Hum Anatomy & Physiology II
Hum Anatomy & Physiology II KINS 2532
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Metabolism Metabolismall chemical reactions necessary to maintain life Anabolism building of molecules 0quotquot 39 quot of 39 39 Cellular Respiration purpose is to efficiently harness energy from glucose ATP yielding reactions are redox reactions Oxidation 7 reduction reactions energy yielding reactions within cells are oxidation reactions Oxidation occurs Via the gain of oxygen or the loss of hydrogen Oxidized substance always loses an electron Reduced substances always gains an electron Enzymes that remove hydrogens are called dehydrogenases Need a coenzyme to hold on to electron Two important coenzymes l Nicotinamide adenine dinucleotide NAD based on niacin 2 FlaVin adenine dinucleotide FAD based on ribo avin Sites of ATP formation during cellular respiration l Glycolysis in cytoplasm 2 Kreb s Cycle in mitochondria 3 Oxidative phosphorylation in mitochondria Mechanisms of ATP Synthesis 1 substratelevel phosphorylation high energy phosphate groups are transferred directly from phosphorylated substrates to ADP 2 oxidative phosphorylation the use of oxygen molecules to attract electrons and add inorganic phosphate to ADP I Carbohydrate metabolism Oxidation of Glucose glucose enters cells by facilitated diffusion aided by insulin converted to glucose6phosphate in cytoplasm Three pathways 1 Glycolysis in cytoplasm cleaved into 2 molecules of pyruvic acid forms net 2 ATP and 2 NADH If Formation of NADH H two electrons and a proton are removed from the substrate and added to NAD the other proton H is released into solution 2 Krebs cycle occurs in the mitochondria Pyruvic acid is converted to 2 molecules of acetyl CoA series of redox reactions produces C02 NADHH FADHz and 2 ATP per glucose can also be used to produce fatty acids and nonessential amino acids 3 Electron Transport Chain and OXidative Phosphorylation occurs across the inner mitochondrial membrane electrons are taken from NADHH and FADHZ electrons travel toward 0 H reenter through ATP Synthase Proton motive force NET RESULT FROM GLYCOLYSISKREBS CYCLEOXIDATIVE PHOSPHORYLATION 36 ATP Glycolysis is turned off by high levels of ATP extra glucose is stored as glycogen process is called glycogenesis when blood glucose is low glycogen is split and converted to glucose process called glycogenolysis II Lipid Metabolism Betaoxidation 7 Fatty acids are converted to acetyl CoA Glycerol is converted to glyceraldehyde phosphate and enters glycolysis Lipogenesis 7 occurs when cellular ATP and glucose levels are high Acetyl CoA molecules are combined to form fatty acid chains Glyceraldehyde phosphate is converted to glycerol Thus excessive carbohydrate intake provides necessary materials for neutral fat production Lipolysis 7 breakdown of stored fats into glycerol and fatty acids Essentially the reverse of lipogenesis Both glycerol and fatty acids enter lipid oxidation When glucose is low molecules in the Krebs cycle are converted to glucose This prevents acetyl CoA from entering the cycle and it accumulates The liver then converts the acetyl CoA to ketones or ketone bodies Ketosis results when ketones accumulate faster than they can be used Ketones are excreted in urine Ketosis is a common consequence of starvation unwise dieting and diabetes mellitus Ketosis can also cause metabolic acidosis Blood pH drops and produces hyperventilation and sometimes coma 111 Protein metabolism Oxidation of amino acids for energy steps 1 Transamination transfer of amine NHz group to alphaketoglutaric acid amino acid now becomes a keto acid 2 Oxidative deamination amine group of glutamic acid is removed as ammonia NH3 and thus aketoglutaric acid is regenerated ammonia molecules combine with CO to form urea and water 3 Keto acid modi cation keto acid produced by transamination is converted to pyruvic acid or another metabolite that can be plugged into the Krebs cycle process is reversible therefore deaminated amino acids that have been converted to pyruvic acid can be reconverted to glucose Body maintains a catabolicanabolic steady state refers to the constant breakdown and buildup of molecules Blood contains nutrient pools nutrient pools amino acid pool and carbohydratefat pool quot quot controls act to equalize concentrations of nutrients between two states 1 Absorptive nutrients rushing in from GI tract anabolic processes exceed catabolic excess metabolites are converted to fat 2 Postabsorptive state period between meals primary goal is to maintain blood glucose levels Sources of blood glucose during postabsorptive state 1 Glycogenolysis in liver 2 Glycogenolysis in skeletal muscle 3 Lipolysis in adipose tissue and liver 4 Catabolism of cellular protein Role of Liver in metabolism 1 Packages fatty acids into forms that can be stored and transported 2 Synthesizes plasma proteins 3 Forms nonessential amino acids converts ammonia to urea 4 Stores glucose as glycogen 5 Store certain vitamins 6 Conserve iron 7 Degrade hormones 8 Detoxify alcohol and drugs Cholesterol Metabolism Cholesterol serves as structural basis for bile salts steroid hormones and vitamin D about 15 of blood cholesterol comes from diet 85 is produced from Acetyl CoA in the liver Lipoproteins lipids and cholesterol need to be bound to proteins in order to be soluble in water the higher the of lipid the lower the density the lipoprotein the higher the of protein the higher the density Three types of lipoproteins 1 High density lipoproteins HDLs transports cholesterol to liver from tissues good 2 Low density lipoproteins LDLs when fat is unloaded residues become LDLs bad transport cholesterol 3 Very low density lipoproteins VLDLs transfer triglycerides to adipose tissue HDL pulls cholesterol from body tissues including blood vessel walls LDL takes cholesterol to tissues for plasma membrane structure and hormone production High HDL levels are good means that cholesterol is being taken to liver for degradation Factors regulating plasma 39 39 39 high levels slow liver from producing cholesterol however liver still makes a certain base amount therefore diet only slightly affects serum cholesterol saturated fatty acids stimulate cholesterol production unsaturated fatty acids stimulate excretion of cholesterol smoking coffee are linked to high LDL levels Metabolic rate and body heat metabolic rate rate of body to expend energy measured as heat produced by calorimeter by respirometer 1 L 02 48 kcal of heat basal metabolic rate BMR heat produced to support basic body functions measured under controlled conditions BMR measured as kcal per square meter of surface area per hour kcalmzh Factors that affect BMR 1 Surface area 7 as the ratio of surface area to body volume increases so does BMR 2 Age 7 younger higher 3 Sex gender 4 Stress 5 Hormones thyroxine increases ATP use in cells Total metabolic rate TMR sum of all voluntary and involuntary actions Regulation of body temperature 980 F 1000 F average 1060 F causes convulsions in adults 1100 F death impedes function of neurons denatures proteins core temperature organs shell temperature limbs skin and body wall Mechanisms of heat exchange 1 Radiation 7 loss through infrared waves 2 Conduction heat transfer between two objects that come in contact 3 Convection warm air replaced by cool air 4 Evaporation 7 water absorbs heat before vaporizing Thermoregulation is controlled by hypothalamus Thermoregulatory centers Heatloss center Heatpromoting center Input received from 1 Peripheral thermoreceptors in skin 2 Central thermoreceptors in brain initiates a response via autonomic effector pathways Heatpromoting responses 1 Vasoconstriction 2 Increased BMR 3 Shivering 4 Enhanced thyroxine production 5 Behavior Heatloss responses Meiosis cell division the produces haploid sex cells two nuclear divisions occur and therefore are referred to as Meiosis l and II Meiosis l 1 Prophase 1 tetrads are formed by synapsis of homologous chromosomes sections of DNA are exchanged between chromatids 2 Metaphase 1 tetrads are arranged along the equator ofthe cell Anaphase telophase and cytokinesis 1 take place like mitosis Meiosis 2 occurs just like mitosis except there is no second replication of DNA Genetics diploid the normal number of chromosomes haploid halfthe number of chromosomes Character heritable feature such as flower color Trait each variable for a character such as white pink etc Karyotype complete set of chromosomes displayed in homologous pairs Alleles similar genes at the same locus from different parents Homozygous when the alleles are the same Heterozygous when the alleles are different Dominant one allele that masks or suppresses the expression of another Recessive the allele that is masked Genotype the genetic makeup of an individual Phenotype the physical characteristics that are expressed Phenotype Genes Environment Sexual sources of genetic variation 1Law of Segregation f blending was correct F1 hybrids from a purpleflowered and a whiteflowered would all have palepurple flowers However Mendel showed that all F1 offspring had purple flowers What happened to the white flowered plants genetic contribution If it were lost then F1 plants could only produce purple flowers in the F2 generation Mende allowed F1 plants to selfpollinate this resulted in white owered plants appearing in the F2 generation There was a ratio of 3 purple flowered plants for every 1 white flowered plant Mendel reasoned that the purple ower was the dominant trait and that the heritable factor causing the white flower was not diluted Four related ideas summarize Mendel s explanation 1Alternative versions of genes account for variations in inherited characters the purple flowered allele and the white flowered allele are examples of two variations for a given gene 2For each character an organism inherits two alleles one from the mother and one from the father 3 If two alleles differ then one the dominant allele is fully expressed in the organisms appearance the other the recessive allele has no noticeable effect on the organism39s appearance 4The two alleles for each character segregate during gamete production thus an ovum and sperm receive only one of the alleles lf contrasting alleles are present 50 of the gametes receive the dominant while 50 receive the recessive this is Mendel s Law of Segregation The Testcross if we have a purple owered plant we cannot know the genotype for sure If we cross this plant with one that has white owers the we can determine the genotype based on the offspring Ifthe genotype is PP then the offspring will be all purple Ifthe genotype is Pp then 12 will be purple and 12 will be white The breeding of a recessive homozygote with an organism dominant phenotype but unknown genotype is called a testcross can be illustrated using a Punnett Square based the Law of Segregation 2Law of independent assortment what would happen if Mendel crossed pea plants that differed in two characters This is called a dihybrid cross Two ofthe seven characters Mendel studied were pea color and shape From monohybrid crosses Mendel learned that the allele for yellow was dominant and the allele for green was recessive Likewise the allele for smooth shape was dominant and wrinkled was recessive yellowround YYRR and greenwrinkled yyrr were crossed Are these two characters transmitted from parents to offspring as one package If so we should nd a 31 ratio of Yellowround to greenwrinkled in the F2 generation Mendel found the offspring of the F2 generation to have a phenotypic ratio of 9131311 this indicated that each pair of alleles is distributed independently this is because chance determines how the tetrads align on the metaphase 1 spindle therefore maternal and paternal chromosomes are randomly distributed to the daughter cells 2quot calculates the number of gamete types from independent assortment n the number of homologous pairs lf n3 then 2quot 8 different gametes or combinations In a human male s testes there are 223 or 85 million possibilities Mendelian inheritance reflects rules of probability the probability scale ranges from 1 t0 0 An event that is certain to occur has a probability of 1 An event that is certain NOT to occur has a probability of 0 For a twoheaded coin the probability of tossing heads is 1 while the probability of tossing tails is 0 With a normal coin the chance of tossing heads is 12 and the chance of tossing tails is 12 Each coin toss is an independent event and is unaffected by previous events The rule of multiplication How do we determine the chance of two independent events happening at the same time like tossing two coins and both of them coming up heads First compute the probability of each single event In this case tossing a heads 12 Then multiply the individual probabilities to calculate the overall probability X With flower color as the character the genotype of a given F1 plant is Pp What is the probability that a particular F2 plant will have white flowers For this to happen both the ovum and sperm must carry the p allele The probability that an ovum will carry the p allele is 12 which is the same for the sperm Therefore using the rule of multiplication the probability that both will come together at fertilization is 12 X 12 1 Rule of addition What is the probability that an F2 plant from a monohybrid cross will be heterozygous According to the rule of addition the probability that an event can occur in two or more different ways is the sum of the separate probabilities of those ways So from a monohybrid cross the chance of Pp is 1A and the chance opris Aso 12 Using rules of probability to solve genetics problems What do we do with trihybrid crosses For example Mendel crossed purple owered plants that have yellow round seeds with purpleflowered plants that have green wrinkled seeds PprRr X Ppyyrr What is the chance that the offspring will have at least two recessive traits all genotypes that ful ll this condition ppnyr pprrr Ppyyrr PPyyrr and ppyyrr next use the rule of multiplication to calculate the individual probabilities of each of these genotypes PPYYRF probability of pp X 12yy x 12 Rr 116 pprrr X12X12 2116 Ppyyrr 12x12xy2 2216 F Pyyrr wxizxyz 2116 ppyyrr wxizxyz 2116 nally use the rule of addition to pool the probabilities for ful lling the condition of at least two recessive traits Chance of two recessive traits 616 or 38 Crossover of homologous and genetic recombination the exchange of segments of DNA produces genetic combinations not seen in parents A Random fertilization fertilization of an egg by any sperm 85 million X 85 million 72 trillion possible zygotes The relationship between genotype and phenotype is rarely simple Incomplete dominance for some traits the F1 hybrids have an appearance somewhere in between the the phenotypes of the parents for example when red snapdragon plants are crossed with white all the F1 hybrids have pink flowers Is this evidence for blending No if blending had occurred then all offspring in the F2 generation would be pink What is a dominant allele in complete dominance we see that the phenotypes of the heterozygote and dominant homozygote are indistinguishable in codominace both alleles are separately manifest in the phenotype For example ABO blood groups The genotype for A blood is AA for B blood is BB and for AB blood is AB For any character dominancerecessive relationship depends on the level we examine the phenotype for example TaySachs disease Brain cells are unable to metabolize a particular lipid which Accumulates in the brain and the cells then die Only individuals with both TaySachs alleles have the disease Theref0re at the organismal level TaySachs quali es as recessive At the biochemical level it is classi ed as incomplete dominance The enzyme de ciency can be detected in heterozygotes who have an activity level ofthe enzyme that is intermediate between normal and diseased individuals Heterozygotes lack symptoms of the disease because half the normal amount ofthe enzyme is sufficient Thus at the molecular level the normal allele and the TaySachs allele are codominant Multiple alleles refers to genes that exist in more than two allelic forms Such as ABO blood groups l leiotropy the ability of a gene to affect an organism in many ways Alleles that are responsible for hereditary diseases often exhibit this characteristic The amino acid substitution in sicklecell anemia leads to a breakdown of RBCs clumping of cells and clogging of small vessels and accumulation of sickled cells in the spleen Epistasis In some cases a gene at one locus alters the phenotypic expression of a gene at a second locus In mice black coat color is dominant to brown B for black and b for brown A second gene locus determines whether or not pigment is deposited Deposition of pigment is dominant The rst locus determines coat color but the second determines if the pigment is produced What happens if black mice who are heterozygous for both genes Bch Polygenic inheritance quantitative characters exist in graduations in human populations and are produced by more than one gene when polygenic traits are plotted on a graph they produce a bellshaped curve Environmental in uences on phenotype UV radiation Drugs Nutrition Hormonal deficits eg influence from other genes Nontraditional inheritance l Genomic imprinting genes marked as paternal or maternal during gametogenesis some genes have different effects ifthey came from the mother or father 2Extrachromosomal inheritance mitochondrial genes Genetic Screening carrier recognition pedigree blood test feta testing used when there is a known risk of a genetic disorder most common is amniocentesis normally reserved for after week 14 tests performed on sloughed off fetal cells in amniotic fluid chorionic villi sampling faster than amniocentesis Discovery of a sexlinked gene Thomas Morgan bred fruit flies to study genes and chromosomes He eventually found a mutant for white eye color He then mated the whiteeyed male with aredeyed normal eye color female His F1 generation all had red eyes suggesting that the allele for red color was dominant His F2 generation produced the expected 31 phenotypic ratio however the whiteeyed trait only showed up in males All females had red eyes while half of the males had red and the other half white Linked genes tend to be inherited together because they are located on the same chromosome Morgan also studied body color and wing size in flies Normal ies have gray bodies and normal wings Mutant ies have black bodies and vestigial wings Morgan crossed female dihybrids with males that had both mutant Phenotypes According to Mendel s law of independent assortment this should produce four phenotypic classes of offspring Morgan found a different ratio than 11 1 1 He found many more of the parental phenotypes and fewer recombinant types Recombination data can be used to map a chromosome s loci the recombination frequency between body color and wing size is about 17 crossingover results in 17 of offspring having a combination of body color and wing size different from the parents different recombination frequencies might be explained by the distance between the loci on the chromosome carried on the same chromosome is a gene for eye color called cinnabar The frequency of cinnabar eyes and black bodies is about 9 Therefore crossovers between body color and wing size are about twice as frequent as crossovers between body color and eye color 17 v 9 The distance between genes is measured by how many map units separate them the loci for black color and the locus for cinnabar are 9 map units apart the distance between wing size and black color is 17 units What is the sequence of the genes We can eliminate the sequence blackwing sizecinnabar since we know cinnabar is closer to black color that wing size is this leaves two possible sequences cinnabarblackwing size and blackcinnabarwing size the frequency of recombination between cinnabar and wing size should reveal the correct sequence the first possible sequence predicts that cinnabar and wing size are about 26 map units apart 179 while the second predicts a separation of about 8 studies found the frequency of recombination between wing size and cinnabar was 95 this suggested the sequence is black colorcinnabarwing size Sometimes genes are so far apart that they cross over all the time Such is the case with Mendel s seed color and pea ower color which are known to be on chromosome 1 they are so far apart that linkage is not observed Sex linked disorders in humans if a sexlinked trait is due to a recessive allele a female will express the phenotype only if she is a homozygote hemizygous is the term reserved for males since they have only one locus Any male receiving the recessive allele Will express the trait lDuchenne Muscular dystrophy present l in every 3500 births Victims rarely live Duchenne Muscular Dystrophy Etiology Xlinked recessive disorder inherited but can be a mutation Exact mechanism is un nown typicaly presents in boys 37y Signs and Symptoms proximal muscle weakness causes waddling gait toewalking lordosis di iculty climbing stairs Develops first in the pelvic girdle followed pectoral girdle most die by age 20 Diagnosis cinical findings family history biopsy Treatment no specific therapy exercise encourage Hemophilia Etiology Xlinked recessive Lack a gene for either clotting factor VIII or IX due to a point mutation or deletions of part of the gene Signs and Symptoms Different abnormal allelic hemophilic genes support different levels of factor Activity The patient with a factor VIII or IX level lt1 will have severe bleeding Episodes throughout life Min0r trauma can result in extensive tissue hemorrhages Patients with levels in the 5 of normal range have mild hemophilia They rarely have spontaneous hemorrhages Diagnosis blood screening pedigreefamily history Ireatment avoid using aspirin Preventative dental care to reduce chances of surgery or extraction Replacement therapy that adds factors to patient s blood Drugs that stimulate factor VIII production Xinactivation in females when inherited one X chromosome is active and the other is inactive The selection of which X to be inactive is random Theref0re females have some cells where the paternal X is inactive and others where the maternal X is inactive If a female is heterozygous for a sexlinked trait half of her cells will express the trait and half won t this is seen in ChristSiemensTouraine syndrome Alterations of Chromosome Number sometimes members of a homologous pair of chromosomes do not move apart during meiosis l or sister chromatids do not separate during meiosis II this leads to an abnormal number of chromosomes called aneuploidy If a cell contains an extra it is called trisomic for that chromosome if a cell lacks a chromosome it is called monosomic for that chromosome Alterations of chromosome structure breakage can lead to fourtypes of changes 1Deletion a chromosomal fragment is lost during division 2Duplication the lost fragment attaches to a homologous chromosome 3lnversion the fragment reattaches to the chromosome but in a different Zill9rtanslocation a fragment rejoins a nonhomologous chromosome Trisomy 21 Down Syndrome 95 have an extra chromosome 21 Overall incidence is 1 in every 700 Closely related to age of mother In early childbearing years is 12000 after 40 yrs rises to 14 Signs and symptoms microcephaly and brachycephaly are present eyes are slanted with epicanthic folds flattened nasal bridge tongue is large furrowed and lack central fissure life expectancy is 4050 yrs Noncoding sequences and gene duplications account for much of the genome Autonomic Nervous System motor neurons to cardiac muscle smooth muscle and glands motor unit of ANS is a two neuron chain a preganglionic neuron With a cell body in the brain or spinal cord a postganglionic neuron with a cell body in an autonomic ganglion preganglionic axons are myelinated postganglionic axons are unmyelinated higher brain centers coordinate visceral motor activities nearly all spinal nerves carry somatic and visceral neurons A Divisions of the Nervous Svstem both divisions serve the same organs but typically have opposite effects circumstance called dual innervation Divisions are distinguished by unique origin sites different fiber length location of ganglia Pouch quot quot 39 W division preganglionic fibers originate from cranial and sacral nerves synapse with postganglionic neurons in ganglia close to or within the target organ postganglionic neurons secrete acetylcholine postganglionic axons are very short generally thought of as resting and digesting system blood pressure respiratory rate heart rate are kept at low levels gastrointestinal tract is actively digesting food S quot quot Division T39 39 39 y supplies internal organs and glands of skin preganglionic bers originate from thoracic and lumbar spinal segments preganglionic neurons exit SC and pass through white ramus communicans to enter paravertebral ganglia paravertebral ganglia are linked together to form the sympathetic chain or trunk Preganglionic bers can 1 Synapse within ganglion of the same spinal segment 2 Can ascend or descend to synapse 3 Can emerge from ganglion and travel to prevertebral ganglion such as the celiac ganglion preganglionic bers that eXit paravertebral ganglia travel along splanchnic nerves postsynaptic neurons from the paravertebral ganglion enter ventral ramus via the gray ramus communicans Innervation to and from collateral ganglia l Celiac ganglion 7 preganglionic from thoracic ganglia 5 to 9 or 10 via greater splanchnic n Postganglionic bers to stomach spleen liver small intestine and kidneys 2 Celiac and superior mesenteric ganglia 7 from thoracic 9 and 10 via lesser splanchnic n postganglionic bers to small intestine and colon 3 Celiac and inferior mesenteric ganglia 7 from lumbar ganglia Via lumbar splanchnic n 7 postganglionic to distal colon urinary bladder and reproductive organs Visceral re ex arcs same as somatic re ex arc except that it has a two neuron motor chain visceral pain inputs follow same pathways in brain as somatic brain interprets as more common somatic pain called referred pain Neurotransmitters l Acetylcholine Ach 7 released by all preganglionic axons of the ANS and all postganglionic axons of the parasympathetic division 1 Norepinephrine NE 7 released by most postganglionic sympathetic axons response activation or inhibition of a target cell to either depends on the type of receptor Cholinergic receptors bind to ACh Two types 1 Nicotinic found on motor end plates all postganglionic neurons and hormone producing cells of the adrenal medulla binding with ACh is always stimulatory and results in excitation of target cell 2 Muscarinic 7 located on all effector cells stimulated by postganglionic cholinergic fibers eg all parasympathetic target organs effect of ACh binding is dependent on target organ it slows cardiac muscle function but activates smooth muscle cells in GI tract Andrenergic receptors Two classes with various subclasses organs that respond to NE display one or both types 1 Alpha 7 generally NE stimulates cells with alpha receptors 1 Beta 7 generally NE inhibits cells with beta receptors Effects of Drugs knowing the location of certain receptor types aids in the prescription of drugs Examples Atropine anticholinergic 7 blocks parasympathetic effects administered before surgery to prevent salivation and dry respiratory tract competes with binding sites Betablockers antiandrenergic 7 blocks sympathetic stimulation of beta andrenergic receptors in cardiac muscle to slow heart rate and reduce arrhythmias Tricyclic antidepressants 7 prolong activity of NE on receptors promotes feeling good Localized versus diffuse effects parasympathetic preganglionic neurons synapse with one or a few neurons ACh is quickly destroyed therefore effects are usually localized and short lived sympathetic is reverse preganglionic neurons synapse with many responds in diffuse and highly interconnected way Interactions of Autonomic Divisions antagonistic interactions in fight or ight syndrome heart rate is increased digestive functions are inhibited when threat passed parasympathetic restores resting rate of heart and breathing cooperative effects parasympathetic increases blood ow to external genitalia sympathetic simulates ejaculation or peristalsis of vagina Control of Autonomic functioning combination of neurons and hormones begins in hypothalamus relays with reticular formation and then motor neurons in brain stem and spinal cord Blood Vessels arteries gt arterioles capillaries veins gt venules Structure of vessel walls three layers surround lumen l Tunica intima 2 Tunica media 3 Tunica adventitia vasa vasorum Capillaries consist of a thin tunica intima sometimes they are just one epithelial cell thick Materials can pass through capillaries 1 By direct diffusion 2 By transport vesicles 3 Through intercellular clefts 4 Through fenestrations pores 3 types of capillaries 1 Continuous tight junctions 2 Fenestrated many pores in cells 3 Sinusoidal large irregular lumen Kupffer cells Capillary beds vast network contain precapillary sphincters Venules consist entirely of tunica intima Veins have three tunics except thinner than arteries sometimes called capacitating vessels contain valves Anastomoses arteriovenous capillary beds Introduction to blood ow blood pressure and resistance blood ow volmin owing through a structure blood pressure force per unit area exerted by blood on vessel wall resistance opposition to ow and friction blood ow F Difference in BP peripheral resistance Arterial blood pressure result of l Elasticity of aa close to heart 2 Volume of blood forced into them systolic pressure blood ow into aorta from L ventricle diastolic pressure bicuspid valve closes walls of aorta recoil to maintain pressure on decrease blood volume Hypertension generally if systolic is above 140 and diastolic is above 90 quotnormalquot BP is approx 1207080 Pulse pressure difference between systolic and diastolic Mean arterial pressure MAP diastolic pulse pressure 3 Some causes ofhypertension l Arteriosclerosis increase in peripheral resistance 2 Increased blood volume some causes are kidney disease adrenal tumor Factors aiding venous return 1 Respiratory pump 2 Muscular pump Control of blood pressure Shortterm Neural l Vasomotor center 2 Baroreceptor initiated re exes 3 Carotidaortic complexes Chemical 1 Adrenal medulla norepinepherine 2 Antidiuretic hormone ADH 3 Atrial natriuretic peptide ANP Longterm Renal regulation Longterm Renal regulation Flow through capillaries oxygen carbon dioxide and most nutrients pass through walls due to diffusion Fluids are forced out through vessels at arterial end and allowed back in at venous end Direction and amount of ow is determined by Hydrostatic pressures Colloid osmotic pressures Hydrostatic pressures force exerted by a uid pressing against a wall Capillary hydrostatic pressure pressure that forces uid through capillary walls Interstitial uid hydrostatic pressure pressure produced by LP and opposes cap HP Pressure of IF is usually zero because it is absorbed into lymphatic vessels Therefore net effective hydrostatic pressure is equal to the capillary pressure at each end of the bed Colloid osmotic pressures created by the presence of large nondiffusible molecules These encourage osmosis when concentration of water is lower than on the opposite side of the capillary membrane Called oncotic pressure Oncotic pressure is usually lower in IF Net osmotic pressure pulls water into vessels Net filtration pressure determined net gain or loss of uid from blood Fluids will leave blood if net hydrostatic is greater than net colloid Fluids will enter blood if net colloid is greater than net hydrostatic At the arterial end Net ltration pressure cap HP 7 IF press 7 cap OP 7IF OP NFP 350 7 26 71 NFP 35 725 10 mm Hg Therefore uid is forced out of the capillary At the venous end NFP 170 7 261 NFP 1725 18 mmHg Therefore uid is drawn back into the blood However more uid enters the IF and results in a net loss of 15 mlmin this is the uid that is eventually returned to circulation via lymphatic vessels CHANGE IN EITHER HYDROSTATIC OR COLLOID PRESSURES WILL SUBSTANIALLY CHANGE FLUID SHIFTS Speci c vessels and pathways Internal carotid a 7upon entering the skull through the carotid canal is divides into the l anterior cerebral a 7 supplies all of the medial cortex from entire frontal lobe to the parietooccipital sulcus 2 middle cerebral a 7 supplies entire lateral surfaces of the hemispheres From subclavian the vertebral a ascends the neck through the transverse foramen of the cervical vertebrae R and L vertebral aa merge to form the basilar a after entering the skull through the foramen magnum vertebral aa supply medulla meninges cerebellum Basilar a posterior cerebral a 7 supplies inferior aspects of the temporal lobe lateral and medial surfaces of occipital lobe and thus supplies the visual cortex Circle of Willis formed from an anastomosis between the two internal carotid aa and the two vertebral aa Anterior and posterior communicating branches anterior and posterior cerebral aa and the basilar a all contribute to the circle Allows blood that enters through either internal carotid a to reach either side of the brain Celiac Trunk Three major branches 1 Left gastric artery 7 supplies stomach and lower esophagus 2 Splenic artery 7 supplies spleen pancreas and stomach 3 Common hepatic artery 7 stomach pancreas duodenum liver and gall bladder Superior mesenteric artery 7pancreas duodenum small intestine cecum ascending colon transverse colon Inferior mesenteric artery 7 transverse colon descending colon sigmoid colon rectum Femoral artery 7 main arterial supply to lower extremity is a continuation of the external iliac artery in the anterior thigh Descends toward the adductor tubercle of the femur and ends at the adductor hiatus where it enters the popliteal space and becomes the popliteal artery Brachial artery7 begins at the lower border of the teres major muscle as a continuation of the axillary artery provides the main blood supply to the arm Terminates opposite the neck of the radius by dividing into the radial and ulnar arteries Azygous vein 7 drains blood from posterior intercostal vv Median cubital v 7 anastomoses between basilic and cephalic vv The Heart Location Coverings l Fibrous pericardium 2 Serous pericardium Heart wall layers 1 Epicardium 2 Myocardium 3 Endocardium Chambers 2 atria pectinate mm 2 ventricles papillary mm trabeculae camae divided by septa Grooves atrioventricular interventricular Pathway of blood through the heart systemic circuit pulmonary circuit m atrioventricular chordae tendinae tricuspid on right side bicuspid on left side semilunar Blood supply to the heart 1 L coronary artery anterior interventricular a circum ex a 2 R coronary artery marginal a posterior interventricular a anastomoses Venous collection in heart 1 Coronary sinus supplied by great small and middle cardiac VV pathway of VV generally follows cardiac aa Cardiac mm cells short branched and interconnected contained Within ct matrix that is vascularized and connected to brous skeleton intercalated discs functional syncytium Features of cardiac cells 1 Contracts based on allornone law 2 Some cells are selfstimulating 3 Long absolute refractory periods Intrinsic conduction system autorhythmic cells have unstable resting potential movement of K ions dictate contraction reduced K ions ef ux causes less negative charge in cell when threshold is reached Ca channels open Seguence of excitation l Sinoatrial SA node 2 Atrioventricular AV node 3 AV Bundle 4 Bundle branches 5 Purkinje bers Consists of three waves 1 F wave 2 QRS complex 3 T Wave Cardiac cycle all events associated with blood ow during one complete heartbeat systole contraction period diastole relaxation period 1 Ventricular lling 2 Isovolumetric contraction 3 Ventricular ejection 4 Isovolumetric relaxation STUDY GUIDE FOR HUMAN AampP 2 Fourth Exam DISCLAIMER This is not a list of the actual questions that will be used on the exam This is simply a tool to help you focus your study time Ifyou successfully answer these questions it does not guarantee that you will make an A on the exam Exam questions will only cover subjects included in this guide 1 List the functions of the urinary system 2 Where is the kidney located 3 What is the function of the kidney hilus 4 List and describe the coverings of the kidney 5 List and describe the important structures of the internal anatomy of the kidney 6 What is the functional unit of the kidney 7 Describe the anatomy of the glomerulus 8 Describe the anatomy of the Bowman s capsule 9 Define renal corpuscle Describe the function of the proximal convoluted tubule 11 How is sodium reabsorbed How is water reabsorbed in the PCT What is solvent drag Describe the function of the loop of Henle How does the loop of Henle work What is the purpose of the loop of Henle What is the function of the distal convoluted tubule What is the function of the collecting duct How does antidiuretic hormone work What are the effects of aldosterone Compare and contrast juxtaglomerular and cortical nephrons Describe the structure of the afferent and efferent arterioles and why this is important What is the driving force behind filtration in the glomerulus 24 Define vasa recta Explain the juxtaglomerular apparatus and how it works 26 Describe the anatomy of the filtration membrane 27 Define filtrate What is glomerular filtration and how does it work Define glomerular filtration rate 30 List and describe the factors that affect GFR 3 1 How is GFR regulated 32 Explain the myogenic mechanism 33 Explain the tubuloglomerular feedback mechanism 34 How can the sympathetic nervous system control GFR 35 Explain how the Renin angiotensin mechanism works 36 What is meant by tubular secretion 37 What kinds of things are secreted and why Nl b b Ib l b D Ib I gt oxopogcxuAwgo o NNN LAND I N UI NM 000 I NFLAMMATN i Nonspeci c Body Dofonsos wlll attack linc of fence cumfacc banicrs w s Intact skin epidermis Acid mantle and keratin s Intact mucous membranes Gastric juica acidic 8 kills bacteria acid mantla of vagina mucus saliva tearsnacrimal secretions urine ushing function protects by not allowing microorganisms to stay in the urinary system x vmund Iim of nnnspeac 3 annular chamical defenms Phagocytes in ammatory response 39 portant component antimicrobial proteins co leme39 t interferons fights viruses fever 2nd line of defense cellular defenses 7L r 391 W r 39 iiiMW 39 wan lie2 1 Macrophages big eaters Dendritic cells of epidermis I Macrophages of the lungs ZNeUtroPh39Is Kuppfer cells in liver Resp39ratorybur3t Microglia in the brain Phagocytos39s 3Eosinophis Weakly phagocytic i151 L WLLEifquot lzil ElL ljti if mCaliwitvii gf fi ti Can lyselkill cancer cells and virusinfected cells Do not depend on specific antigen recognition but detect lack of self cell receptors Do not exhibit a memory response and are nonphagocytic Secrete inflammatory chemicals and perforins In ammation reaction of vascular tissue to injury A Fiy f iii ii JLEEQEL QU iii i0 imiiii y iii o iii imgp M 3 Inerr gsgb kfhem xls W La muffquot L f V UUUU CC L U LF U j MU l 7 3 i If Pumose of in ammation 7w LBJITOB capillary or venule r hawk Viki L Prgvgmm wiglim wig algiali mg M E N U U Causes of acute inflammation V Physical damage Trauma radiation burns frostbite gt Chemical substances Acids and bases V Microorganisms Bacteria with exotoxins V Other agents Necrosis infarction gt Exogenous vs endogenous The inflammatory response gt Changes in blood flow vessel calibre gt Increased permeability of blood vessels and formation of the fluid exudate gt Escape of cells emigration of the neutrophils from the blood into the tissues The changes are essentially the same whatever the cause and wherever the site Cardinal signs of inflammation El Newman gtm gt W 7 A quot L39 Q C 058d sz 39rgmmm 5211 lag c D quot39 sphincter Canzllarles u a N105 A 1RE UJJJI A 39g Q Q Prefarenrr l hannoi ULA J 39 VANJJJJ lt 7 v a Venule 3 x N JISELQ fim 1 le E1 Acute inflammation DHalauon gt gt x v o Qr quotquot 39R pvfbn 591441 01 EN 0144 L Drecapillary Lr ihj w gm 5 p hi n C18 r w f I mrrnea aam Mos caplllanes x r 7 vwx n v 39 2 LUJM m H Dx latauon increased permeability of blood vesseis 1 39F 1 quotH gtgt x quot defLi 392 d 39 iimisii Sigiii ii 9Iriiifrii i aii ii iaswg iliicgg VA 439 L9 E i Exudatiom QiiQ Ej JJ iii iiif iiiiii filing i i riiiigi db ESGEPQ Of Wins E imiigii ifiiigimi iiigm times iilam i iiimim i i iii Ei ii ii ltiii ii i ayggigiyiiign Wifiiriiga iiii i igigiicd ai 39 immifiii i mi iliiigia iicaigaiiz i m r V w x a air LcaJEJLEJ U iiia i icijmi i 4 iii iiili iii l 1930 iii iia39gadiiiiaziii igi i ix iiyiii iii E C ili i iiiii fiiiih ifiiijifisrsiimiiiliyiiii tnf ii milt iiiimiiiia ii PE 4 MECHANISMS OF VASCULAR LEAKAGE IN ACU I I E INFLAMMATIOM Gaps Endmhelial conimctian 1 Vxenuies 39 Hamactive median r5 histamine Ieukolrienes em 7 7 7 Chemical mediators released from cells Histamine vascular dilatation increased vascular permeability mast cells basophils eosinophils and platelets Serotonin from mast cells and platelets Prostaglandins derived from arachidonic acid synthesized by many cell types potentiate vascular permeability and induce platelet aggregation Leukotrienes k synthesized especially in neutrop irg fj Arachidamic Acid Cascade m The Arachidonic Acid Cascade Celt Membrane Phospholipids Nachidonic Acid Gamma Endoperoxides j Hydroperoxides j v prg5tagladdigs membexanes I Leukot enesJ HOWD AV T Z OONUquotquot crophages 00x2 quot1 Plasma factors Coagulation kinin 8 br no y c systems complement system a g gg mg 63m Ems fitn h7 pgs lmrzsy D 3 v Alloml w pathway Chassical pathway is 5mgquot antigen antibody M 333 cannula pmysamhaddas 4 Fantor B Factor D and Faslqr Complex Pm d n Dpaaniastion Causa s In ammation mats bacierjal su acas stimulates hfslamha enhanqu release 39I39IGI39EGEed blood I311an vessel pannaabiliw chamotaclic at racnicm of phagocytas 911 Insermn ul MAC and call lysu holes in targei a 39s membrane Copynghl 2901 Esmamin Cummings 3h Imprlnl CII39 Addison 39I39belSl jv Llilf lglfl39ls ln Inc Fluid Exudate gt The increased vascular permeability means that large molecules such as proteins can escape from vessels gt The exudate fluid a high protein content up to 50 gll immunoglobulins coagulation factors including fibrinogen gt There is a considerable turnover of the inflammatory exudate since it is constantly drained away by local lymphatic channels to be replaced by new exudate M Major Gem of acute in ammation Neutroph s 39 I TBacteria m 3 gocytosis H 77L Bl oidlapil ar Ie W or VBI ILI Margination IE 9 E u1 1mfilg ltx2 i U WEN A J j39q J Emigration of W30 2 eration of laukecytes by active amoeboid movement through the walls of venules and small veins 2 Neutmphi ls eoslnophils and macrophages can insert pseudopodia between endothellal cells migrate through the created gap and then on through the basal lamina into the vessel wall The defen appears ta be selfsealing and the endothelial cells are not damaged by this prom Chemotaxis of neutrophils gt attraction of neutrophils from the vessel lumen into a damaged area gt mediated by chemotactic factors C5a LTB4 bacterial components gt Monocytes follow neutrophils Phagocytosis and respiratory burst Microbe adheres to phagocyle T Q Phagocyte forms pseudopods that event engulf the particle l 77777 7 r 4 quot 7 39 a ng an phagosnme y Phagocylic vesicle is used with a lysosome Fhagolysosome 39 l l G Microbe In fused vesicle l5 killed and digested by Indigesubla and esid Mechanism of neutrophils Phagocytosis Ingestionldigastion of bacteria amp wastes by WHO to rid the wound of infection and debris enhanced by opsonization by antibodies or by complement Respiratory burst Neutrophiis produce hydrogen peroxide su roxide and other oxidizing agents that form a kill ng zone around leadin to Destruction af bacteria Death of neutrophiis Damage to connective tissusf Diapedesis escape of red cells singly or in jets from the capillary process is passive and depends on hydrostatic pressure forcing the red cells out presence of large numbers of red cells in the extravascular space implies severe vascular injury a tear in the vessel wall Role of lymphatics gt In acute inflammation the lymphatic channels become dilated as they drain away the edema fluid of the inflammatory exudate This drainage tends to limit the extent of edema gt The ability of the lymphatics to carry large molecules and some particulate matter is important in the immune response to infecting agents antigens are carried to the regional lymph nodes for recognition by lymphocytes 7 7 7 7 Systemic effects Pyrexia endogenous pyrogens Constitutional symptoms malaise anorexia weight loss Reactive hyperplasia of the reticuloendothelial system Lymph node enlargement splenomegaly in infectious mononucleosis Hematological changes Leukocytosis Anemia blood loss hemolysis Creactive protein Respiratory system major function supply oxygen release carbon dioxide Respiration includes 4 processes 1 Pulmonary ventilation 2 External Respiration 3 Transport of gases 4 Internal respiration Anatom Apex Base Costal surface Mediastinal surface Hilum Root Parietal and Visceral pleurae Right lung is slightly larger than left and has three lobes Oblique and horizontal f1ssures Left lung is diVided into two lobes by an oblique f1ssure and has a cardiac notch for the heart Conducting zone nasal cavity pharynx larynx trachea bronchi and branches warms humidi es and cleanses air Respiratory zone bronchioles alveolar ducts alveoli Nasal Cavity olfactory mucosa respiratory mucosa nasal conchae paranasal sinuses Pha nx l NasopharynX between roof of nasal caVity and soft palate pharyngeal tonsils adenoids 2 OropharynX posterior to oral caVity 3 Laryngopharynx posterior to epiglottis Larynx thyroid cartilage laryngeal prominence epiglottis vocal folds Valsalva s maneuver Trachea RampL primary bronchi secondary bronchi lobar tertiary bronchi segmental bronchopulmonary segments terminal bronchioles Structural changes 1 Cartilage changes from rings to plates 2 Epithelium changes 3 Amount of smooth mm changes Respiratog zone begins with appearance of respiratory bronchioles alveoli protrude from respiratory bronchioles terminal clusters of alveoli alveolar sacs Respiratog membrane combination of alveolar and capillary walls and basal lamina Type I cells 7 participate in gas exchange Type 11 cells 7 secrete surfactant Macrophages 7 roam freely on inner surface Mechanics of breathing consists of two phases 1 Inspiration 2 Expiration respiratory pressures are always relative to atmospheric pressures at sea level atmospheric pressure 760 mm Hg Intral gulmonary gressure pressure within alveoli Intrapleural pressure pressure within pleural cavity 4 mm Hg less than intrapulmonary pressure pleural serous uid keeps lungs quotattachedquot to thorax any condition that equalizes intrapulmonary and intrapleural pressure will result in lung collapse Pulmona ventilation volume changes gt pressure changes gt ow of gases Boyle s law P1V1 13sz when temp is constant Inspiration from action of diaphragm and intercostal mm muscle contraction increases intrapulmonary volume this decreased pressure therefore air rushes in Forced inspiration aided by scalene SCM and pectoral mm Expiration passive relies on relaxation of mm and lung recoil oblique and transversus mm aid in forced expiration Physical factors in uencing pulmonary ventilation l Airway resistance gas ow is directly proportional to pressure gradient gas ow is inverse to resistance resistance from decrease in diameter of airway resistance is greatest in the mediumsized bronchioles 2 Alveolar surface tension forces water draws alveoli together 3 Lung compliance ability of lungs to expand Gas exchanges Dalton s Law of Partial Pressures total pressure exerted by a gas mixture is equal to sum of pressures of each gas in the mixture partial pressure Henry s law Each gas in a mixture will dissolve in a liquid in a manner proportional to its partial pressure External respiration Factors in uencing the movement of gases Factors in uencing the movement of gases 1 Partial pressure gradients and solubilities oxygen diffuses rapidly alveoli into pulmonary capillary blood due to higher partial pressure 2 Structural characteristics of membrane thickness and available surface area 3 Ventilationperfusion coupling Ventilationperfusion coupling local autoregulatory mechanisms adjust to route blood to areas of better ventilation Pcoz affects diameter of bronchioles Poor ventilation causes low P02 and high Pcoz Result is pulmonary capillaries constrict and airways dilate Internal respiration Transport of gases by blood 02 is carried by hemoglobin Hb and dissolved in plasma rst 0 molecule binds and produced a shape change in Hb this makes the binding of other O molecules easier Factors that regulate Hb binding 1 P02 Hb is completely saturated at 70 mm Hg only 2025 of bound 0 is released 2 Temperature Pcoz H concentration or BPG an increase in any ofthese causes a decrease in Oz af nity blood acidity weakens the bond between oxygen and hemoglobin Bohr effect BPG an intermediate in anaerobic fermentation produced by RBCs binds to Hb and promotes Oz unloading HbNO Partnership NO nitrous oxide normally a vasodilator Hb normally a vasoconstrictor NO binds to Hb and is destroyed by heme group then why do capillaries dilate C02 Transport Three forms l Dissolved in plasma 2 Chemically bound to Hb 3 As bicarbonate ion in blood 6070 co2 H20 lt gt H2003 lt gt Ht HCO339 Aided by carbonic anhydrase within RBCs Haldane effect C02 causes 02 to be released by Hb Bohr effect so Hb can then bind with additional C02 In lungs Oz binds with Hb which releases H H bind with HCOg39to produce C02 Control of Respiration inspiratory center in medulla Neurons re and carry signal along phrenic and intercostal nn Produces rate of about 1215 breaths a minute Pons centers pneumotaxic center ne tunes rhythm and prevents overin ating Apneustic center creates deep and slow breathing is inhibited by pneumotaxic center Factors in uencing rate and depth of breathing Pulmonary irritant re exes stimulate a cough or sneeze In ation re ex use stretch receptors in conducting passages to inhibit muscles and allow expiration Higher brain centers Hypothalamus can increase breathing rate when excited STUDY GUIDE FOR HUMAN AampP 2 Fourth Exam DISCLAIMER This is not a list of the actual questions that will be used on the exam This is simply a tool to help you focus your study time Ifyou successfully answer these questions it does not guarantee that you will make an A on the exam Exam questions will only cover subjects included in this guide 1 List the functions of the urinary system 2 Where is the kidney located 3 What is the function of the kidney hilus 4 List and describe the coverings of the kidney 5 List and describe the important structures of the internal anatomy of the kidney 6 What is the functional unit of the kidney 7 Describe the anatomy of the glomerulus 8 Describe the anatomy of the Bowman s capsule 9 Define renal corpuscle Describe the function of the proximal convoluted tubule 11 How is sodium reabsorbed How is water reabsorbed in the PCT What is solvent drag Describe the function of the loop of Henle How does the loop of Henle work What is the purpose of the loop of Henle What is the function of the distal convoluted tubule What is the function of the collecting duct How does antidiuretic hormone work What are the effects of aldosterone Compare and contrast juxtaglomerular and cortical nephrons Describe the structure of the afferent and efferent arterioles and why this is important What is the driving force behind filtration in the glomerulus 24 Define vasa recta Explain the juxtaglomerular apparatus and how it works 26 Describe the anatomy of the filtration membrane 27 Define filtrate What is glomerular filtration and how does it work Define glomerular filtration rate 30 List and describe the factors that affect GFR 3 1 How is GFR regulated 32 Explain the myogenic mechanism 33 Explain the tubuloglomerular feedback mechanism 34 How can the sympathetic nervous system control GFR 35 Explain how the Renin angiotensin mechanism works 36 What is meant by tubular secretion 37 What kinds of things are secreted and why Nl b b Ib l b D Ib I gt oxopogcxuAwgo o NNN LAND I N UI NM 000 Digestive System Digestive processes 1 Ingestion 2 Propulsion 3 Mechanical digestion 4 Chemical digestion 5 Absorption 6 Defecation 1 Digestive activity is provoked by mechanical and chemical stimuli When sensors are stimulated they initiate re exes that 1 Activate or inhibit glands that secrete into lumen and blood 2 Mix lumen contents and moves them along 2 Control of activity is extrinsic and intrinsic either by short reflexes by local plexi enteric or by long reflexes through CNS and autonomic nn also through hormonal cells in various organs GI organs surrounded by peritoneum mesentery retroperitoneal intraperitoneal Splanchnic circulation aa that serve organs and hepatic portal circulation Layers of GI tract 1 Mucosa layers 1 Surface epithelium 2 Lamina propria loose areolar ct 3 Muscularis mucosae 2 Submucosa 3 Muscularis externa smooth muscle 4 Serosa visceral peritoneum in esophagus serosa is replaced by adventitia m 9799 water slightly acidic contains amylase electrolytes lgA antibodies Control of salivation comes from parasympathetic fibers of facial and glossopharyngeal nn Stimulated by chemoreceptors Digestive processes M Mechanical mastication deglutition Chemical mostly involved in breaking down sugars amylase Stomach Chemical pepsin for proteins renin in children for casein milk protein intrinsic factor for absorption of B12 Stomach Microscopic anatomy lining composed entirely of simple columnar epithelium specifically goblet cells Secrete mucus millions of gastric pits are also found in the walls Gastric pits pits lead to gastric glands which are lined with specialized cells In cardia and pylorus the cells primarily secrete mucus In the antrum Gcells produce gastrin Glands in the fundus contain Mucus neck cells produce acidic mucus Parietal cells secrete HCl and intrinsic factor Chief cells produce pepsinogen Enteroendocrine Gcells gastrin serotonin histamine etc Regulation of Gastric Secretion Three phases 1 Cephalic triggered by smell and sight of food 2 Gastric signals from distension peptides and low acidity peptides and alkaline stimulate Gcells to secrete gastrin which in turn stimulates the release of H0 high stomach acidity inhibits gastrin release Mechanism of H0 secretion stimulated by presence of gastrin from Gcells A0h from parasympathetic neurons and histamine from enteroendocrine cells Gastrin and A0h increase permeability of Ca ions Histamine works through cyclic AMP Then H are actively pumped into stomach lumen 0l39 ions are also actively pumped into lumen to stabilize electrical balance 0l39 ions come from blood plasma H come from combination of 002 and H20 Remember 002 H20 lt gt H2003 lt gt H H00339 H00339 is then actively pumped into interstitial fluid it can then bind with H in blood thus making blood that is leaving stomach more alkaline than blood arriving This is called the alkaline tide 3 Intestinal partially digested food enters duodenum intestinal cells secrete hormone that mimics gastrin but this is shortlived high acidity causes small intestine to send signals to inhibit vagal nuclei local re exes also activates sympathetic bers causing constriction of pyloric sphincter Contractile activity of stomach only about 3 ml are sent to duodenum at a time Interstitial cells of Cajal act as pacemakers for contraction rate is constant but initiation and force of contraction are controlled by enteric reflexes and gastrin shape of pyloric region insures that only liquids and welldigested foods pass to duodenu Small intestine villi microvilli lacteals Pyer s patches Intestinal 39uice Secreted by goblet cells and cells of intestinal crypts slightly alkaline to neutralize acidity of stomach w composed of lobules formed by plates of hepatocytes plates radiate around central vein at each corner of the lobule there is a portal triad portal triad 1 Portal arteriole 2 Portal venule 3 Bile duct space between hepatocyte plates sinusoid both arterial and venous blood travel through sinusoid Kupffer cells macrophages reside in sinusoids Hepatocytes 1 Produce bile 2 Store glucose 3 Store fatsoluble vitamins 4 Detoxify eg remove ammonia from blood bile salts and electrolytes are most important functional components bile salts emulsify fats Release of bile when bile sphincter is closed bile builds up and enters gall bladder when fatty chyme enters duodenum intestinal hormone stimulates gall bladder to contract Pancreas Acini clusters of cells surrounding ducts secrete pancreatic enzymes 1 Trypsin for proteins 2 Amylase for starch 3 Lipases for fats 4 Nucleases for nucleotides Pancreas continued lslets of Langerhans alpha cells produce glucagon beta cells produce insulin Large lntestine mostly absorbs water bacterial ora break down cellulose synthesize Bcomplex vitamins and vitamin K Chemical Digestion Carbohvdrates polysaccharides begins in mouth with amylase which works until stomach acidity stops it Breakdown continues in small intestine as pancreatic amylase works The products are oligosaccharides mostly maltose composed of 28 linked monosaccharides Brush border enzymes further digest into monosaccharides eg maltase Proteins begins in stomach with pepsin which breaks down proteins into smaller polypeptides and free amino acids In small intestine pancreatic enzymes such as trypsin break down polypeptides into smaller pieces Brush border enzyme carboxypeptidase removes one amino acid at a time Lipids bile salts coat small fat droplets to make the molecules more accessible to enzymes pancreatic lipases break down fats by removing 2 ofthe fatty acid chains yielding free fatty acids and and a monoglyceride Absorption most nutrients are absorbed through active transport In the case of proteins they are coupled with sodium transport Then travel to capillary blood via diffusion STUDY GUIDE FOR HUMAN AampP 2 Fifth Exam DISCLAIMER This is not a list of the actual questions that will be used on the exam This is simply a tool to help you focus your study time Ifyou successfully answer these questions it does not guarantee that you will make an A on the exam Exam questions will only cover subjects included in this guide 1 2 3 4 5 6 Explain how the digestive activity is provoked Compare and contrast extrinsic and intrinsic control of digestive activity De ne mesentery intraperitoneal and retroperitoneal What is splanchnic circulation and how is it unique List and describe the layers of the digestive tract Describe saliva and its contents 7 List and describe the digestive processes in the mouth 8 9 0 ll ND ID Ib Il D b iD Ib I oxoooquuAgpm NN ND I Explain chemical digestion in the stomach Describe the structure of gastric glands and pits and describe what each cell does Explain how hydrochloric acid is produced Explain the alkaline tide Explain how gastric secretions are regulated Explain how contractile activity of the stomach is controlled Describe the anatomy and microanatomy of the small intestine What is intestinal juice Describe the gross and microscopic anatomy of the liver Explain how the liver lobule works What is a portal triad What does it do Describe hepatocytes and their function What is bile What are its components What is the purpose ofbile Describe the microanatomy of the pancreas and explain the function of alpha and beta cells 23 24 25 the LAWNNNN HOWOONCN LAMB szv 35 List the pancreatic enzymes and their function What is the function of the colon Describe how carbohydrates lipids and proteins are all digested Include processes in oral cavity stomach and duodenum as appropriate Be sure to cover enzymes What are redox reactions Why are they important for making ATP Why is simply burning a molecule of glucose inefficient for ATP synthesis Why is cellular respiration more efficient What are coenzymes Why are they important Explain glycolysis and its products Explain the Kreb s cycle and its products Explain how the electron transport chain and oxidative phosphorylation work Where do NADH H and F ADH2 come from Where do they go In the electron transport chain what is the force that moves the electron At the end of the electron transport chain what happens to the electrons and hydrogen ions The Lymphatic system Functions 1 Transport uids back to blood 2 Plays role in body defense and disease resistance m l Lymphatic vessels oneway system back to heart absent in bone teeth bone marrow and CNS vessels are highly permeable due to 1 Lack of tight junctions between cells 2 Anchoring laments lacteals Lymphatic trunks Lymphatic ducts 2 major 1 Right lymphatic duct 2 Thoracic duct movement of lymph Lymphoid cells tissues and organs 1 Cells Lymphocytes TCells B Cells Macrophages 2 Lymphoid tissue dense network of reticular bers Diffuse lymphatic tissue 3 Lymphoid organs Lymph nodes Inguinal Axillary Functions lter lymph help to activate immune system Structure capsule trabeculae Regions of lymph node Cortex Medulla medullary cords medullary sinus rm Functions extract aged and defective RBCs remove debris Urinary System Functions 1 Filter blood for toxins metabolic wastes and excess ions 2 Regulate blood volume 3 Regulate salt and water levels in blood 4 Produce renin that acts in blood pressure regulation 5 Produce erythropoietin to stimulate red blood cell production Kidney anatomy retroperitoneal hilus vertical cleft permits entry and exit of blood and lymphatic vessels nerves and ureters Fibrous coverings 1 Renal capsule adheres to surface of kidney 2 Adipose capsule helps to hold kidney in place 3 Renal fascia outer covering of dense fibrous connective tissue Internal anatomy 1 Renal cortex renal columns inward extensions of cortical tissue 2 Renal medulla renal pyramids cone shaped tissue masses formed from collecting tubules lobe each pyramid and a portion of associated cortex 3 Renal pelvis major calyx minor calyx Nephron functional unit of kidney Parts 1 Glomerulus capillaries associated with a renal tubule tunica intima is highly fenestrated 2 Bowman s glomerular capsule beginning of renal tubule surrounds glomerulus bilayered l Parietal layer simple squamous epithelium 2 Visceral layer consists of cells called podocytes 3 Renal capsule combination of glomerulus and Bowman s capsule 4 Proximal convoluted tubule 5 Loop of Henle 6 Distal Convoluted tubule 7 Collecting duct Location of Nephrons l Cortical corpuscles are located well into the cortex 2 Juxtamedullary corpuscles located close to medulla loop of Henle extends deep into medulla Capillary Beds of Nephrons l Glomerulus afferent arteriole efferent arteriole diameter of efferent is smaller than afferent creates high blood pressure in glomerulus aids in the forcing of fluid and solutes from the blood 2 Peritubular capillaries cling closely to renal tubules adapted for absorption low pressure porous vasa recta thin walled looping vessels that descend with juxtamedullary nephrons luxtaglomerular apparatus initial portion of distal convoluted tubule found between arterioles juxtaglomerular cells found in arteriole walls smooth muscle cells that contain renin cells are mechanoreceptors that detect blood pressure macula densa tubule cells are chemoreceptors that detect solute content Filtration Membrane porous allows free passage of water and small solutes has three layers 1 Fenestrated capillary walls 2 Visceral membrane of capsule pedicles of podocytes 3 Middle basement membrane prevents large solutes from passing Mechanisms of Urine Formation Filtrate everything in blood plasma except proteins Urine remaining fluid after the tubules have removed most of the water nutrients and essential ions Involves three major processes l Glomerular filtration passive process uids and solutes are forced through membrane by hydrostatic pressure Net filtration pressure approximately 10 mm Hg Glomerular filtration rate GFR total amount of filtrate formed per minute in kidneys Factors 1 Total surface area available 2 Filtration membrane permeability 3 Net filtration pressure normal GFR in both kidneys of an adult 180L per day GFR is directly proportional to net filtration pressure an increase in arterial blood pressure increased GFR dehydration decrease in GFR because of increase in glomerular osmotic pressure Regulation of Glomerular Filtration important to control because it is related to reabsorption in tubules too much filtrate makes it difficult to reabsorb important substances too little facilitates reabsorption of too much including wastes 1 Renal autoregulation intrinsic mechanism Two types of controls 1 Myogenic mechanism smooth muscle cells constrict when pressure is too high helps to restrict blood flow and lower downstream pressure cells will relax when systemic pressure is too low thus allowing maximum flow 2 Tubuloglomerular feedback mechanism directed by macula densa slow moving low osmotic pressure stimulates cells to secrete chemical that dilates afferent arterioles fast moving high osmotic pressure produces vasoconstriction 2 Sympathetic nervous system controls during times of stress sympathetic fibers stimulate release of epinephrine causes strong constriction of afferent arterioles 3 ReninAngiotensin mechanism begins as release of renin by juxtaglomerular JG cells activates smooth muscle of arterioles throughout body also stimulates adrenal cortex to produce aldosterone Aldosterone stimulates reclamation of Na this increases osmotic pressure more angiotensin receptors on efferent arteriole causes more intense constriction than afferent arteriole Renin release is dependent on 1 Reduced stretch of JG cells 2 Stimulation of JG cells activated by macula densa 3 Direct stimulation of JG cells by sympathetic neurons main purpose of reninangiotensin mechanism is to stabilize systemic blood pressure and extracellular blood volume H Tubular reabsorption begins as soon as filtrate enters proximal convoluted tubule transport is transepithelial K and Na sometimes follow paracellular pathway most all glucose and amino acids are reabsorbed 1 Sodium reabsorption always active process requires protein carrier to absorb into cell facilitated diffusion NaK pump moves Na into interstitial uid then moves passively into peritubular capillaries 2 Reabsorption of water ions and nutrients movement of Na establishes electrochemical gradient this favors passive reabsorption of anions negatively charged ions water follows osmotic gradient established by sodium as water leaves concentration of solutes increases these solutes then diffuse out following their concentration gradients this process is called solvent drag 3 Secondary active transport moves glucose vitamins and most cations when carrier molecule transports sodium other molecules quothitch a ridequot all transport molecules have a maximum they can move 4 Nonreabsorbed solutes 1 Some molecules lack carriers 2 Some are not lipid soluble 3 Some are too large to pass through plasma membrane Most important urea creatinine uric acid Absorption in regions of the renal tubule l proximal convoluted tubule all glucose lactate and amino acids 6570 of Na and water bulk of actively transported substances 2 loop of Henle water reabsorption is not coupled with solute reabsorption plays vital role in producing dilute or concentrated urine 3 Distal convoluted tubule and collecting duct finetuning of Na and water reabsorption into blood controlled by aldosterone and atrial natriurectic hormone HI Tubular secretion substances such as H K creatinine and ammonium ions move from blood to tubules therefore urine consists of filtered and secreted substances Tubular secretion important for l Disposing of substances not in filtrate such as some drugs 2 Eliminating undesirable substances that have been reabsorbed 3 Ridding body of excess K ions 4 Controlling blood pH Regulation of urine 39 and volume Osmolality number of solute particles dissolved in lL of water crucial function of kidney is to keep body fluids at 300 mosm similar to plasma Countercurrent mechanism flow of filtrate through loop of Henle flow of blood through vasa recta Loop of Henle countercurrent multiplier l Descending limb is impermeable to solutes and permeable to water osmolality of filtrate increases to 1200 at bottom of loop 2 Ascending limb is impermeable to water and actively transports NaCl to interstitial uid Na and C1 are extruded by ascending limb filtrate becomes increasingly dilute as water moves from descending limb filtrate becomes more quotsaltyquot this salt is removed from the ascending limb and put into interstitial uid the added salt increases the osmolality of the interstitial uid which in turn draws water from the descending limb this process is a positive feedback mechanism that produces high osmolality of filtrate and interstitial uid the opposite ow of filtrate in each limb countercurrent the process of increasing osmolality multiplier 3 Collecting ducts in deep medullary regions are permeable to urea this adds to high osmolality of interstitial uid 4 Vasa recta acts as countercurrent exchanger blood ow is very slow freely permeable to both water and salt blood entering and leaving medulla has same concentration helps to maintain gradient and perform cell exchange at same time Ollt but so what The mechanism of the Loop has two benefits 1 Establishes a vertical osmotic gradient in the medulla gradient is used to concentrate urine therefore it is more concentrated than body uids 2 Because filtrate is hypotonic when it enters ascending limb this allows the kidney to secrete urine that is more dilute than body uids Immunity l Nonspeci c A Tissues integument stomach mucosa saliva mucus B Cells 1 Leukocytes a Monocytes capable of leaving the blood to become macrophages b Neutrophils found in connective tissues most abundant WBC attracted to bacteria and some fungi can create a respiratory burst oxygen is rapidly metabolized into bleach and hydrogen peroxide these surround the neutrophil like a cloud and oxidize the cell wall of bacteria 0 Eosinophils attack parasitic worms too large to be phagocytized also attack a variety of antigenantibody complexes and allergens concentrated in mucous membranes can secrete enzymes that limit action of histamine 2 Natural killer NK kill virus infected and cancer cells destroy by attacking cell membrane with perforins and releasing cytolytic chemicals nucleus then begins to disintegrate C Processes 1 Inflammation Functions 1 Prevents spread of damaging agents to nearby tissues 2 Disposes of cell debris and pathogens 3 Prepares the area for repair process Cardinal signs of acute inflammation 1 Redness 2 Heat 3 Swelling 4 Pain Inflammation begins as a release of chemical signals from injured tissue cells WBCs mast cells and blood proteins Messengers that can stimulate inflammation 1 Histamine from granules of basophils and mast cells 2 Kinins a plasma protein in blood 3 Prostaglandins from fatty acid molecules in plasma membrane 4 Complement refers to a group of 20 plasma proteins in blood U all cause the dilation of local vessels hyperemia or redness some signals also increase the permeability of vessels release of exudate produces edema swelling swelling presses against nerve endings and causes pain pain also produced by sensitizing effects of prostaglandins and kinins edema helps to dilute toxins brings oxygen and nutrients and clotting proteins Phagocyte mobilization during inflammation leukocytosis inducing factors stimulate the increased production of neutrophils characteristic sign of inflammation find damaged area by binding to cell adhesion molecules CAMs called margination continued signaling prompts neutrophils to pass through wall called diapedesis migrate toward chemotactic agents destroy bacteria toxins and dead tissue cells later assisted by macrophages l Fever lnhibits bacterial growth stimulated iron sequestering Accelerates tissue repair Interleukin1 released by neutrophils and macrophages stimulates the release of prostaglandin E PGE raises the core body temperature set point in the hypothalamus Antimicrobial proteins 1 Complement system activation 1 Classical pathway complement binds to antigenantibody complex by complement fixation 2 Alternate combination of complement factors and molecules on cell surface 3 Lectin plasma proteins that bind to carbohydrates each pathway leads to splitting of one particular factor C3 into 03a and 03b Four mechanisms of pathogen destruction from 03a and 03b 1 Inflammation 2 lmmune clearance C3b binds antigenantibody AgAb complexes to RBCs when RBCs travel to spleen and liver macrophages strip off Ag Ab complexes 3 Phagocytosis bacteria and viruses are phagocytized by neutrophils and macrophages C3b assists by opsonization through coating of microbial cells and serves as binding sites 4 Cytolysis C3b catalyzes cascade where other complement proteins are activated and eventually create a membrane attack complex which stabilizes hole in membrane 2 Interferon Some cells infected by a virus secrete proteins that interfere with the virus They bind to the surface of healthy cells and activate a second messenger The activated cell is capable of breaking down viral genes or preventing replication II S ecific Defenses ada tive activity called immune response and its function is to recognize foreign bodies and destroy them Three important aspects of adaptive immunity 1 is antigenspecific 2 is systemic 3 has memory humoral immunity antibodies produced by lymphocytes cellmediated immunity lymphocytes themselves defend body activity called immune response and its function is to recognize foreign bodies and destroy them A Antigens substances that can mobilize the immune system and provoke a response bacteria viruses etc nonself Characteristics of antigens 1 lmmunogenicity ability to stimulate proliferation of speci c lymphocytes and antibodies 2 Reactivity ability to react with products of immunogenicity 1 Haptens molecules that are too small to be noticed M when they combine with the body s own proteins the combination is recognized as foreign 2 Selfantigens MHC major histocompatibility complex proteins molecules on the external surfaces of the body s own cells only immunogenic to other people B Cells of specific immunity immature cells are nearly identical maturity into B or T depends on where they become immunocompetent 1 TCells mature in the thymus lmmunocompetence depends in removing cells that attack MHC proteins process is called negative selection those that interact weakly are allowed to mature into T cells combination of immunocompetence and selftolerance is needed for proper function 2 B cells mature in bone marrow when T and B cells become immunocompetent they display a unique receptor on cell surface these receptors will bind only with a speci c antigen lymphocytes become competent before they meet with antigen this is determined genetically 3 Antigen presenting cells purpose is to engulf foreign particles and display fragments on their own cell surface these fragments are then recognized by T cells major types ofAPCs are interstitial cells Langerhans cells macrophages and activated B lymphocytes these cells also produce signals that activate T cells activated T cells in turn stimulate the production ofAPCs C Processes 1 Humoral Immune Response produced by contact with BLymphocytes binding stimulates endocytosis clonal selection produces many identical Bcells most clones become plasma cells to produce antibodies some remain dormant and serve as memory cells primary response takes 36 days to start serum antibody concentration usually peaks within 10 days a Active humoral immunity occurs when B cells encounter antigen and produce antibodies active immunity can be naturally or artificially acquired vaccines contain attenuated pathogens or pathogen fragments one drawback is that vaccines do not stimulate T cells that generate a strong cellular response many antibodies are produces but cell memory is poor b Passive humoral immunity antibodies are acquired from another human or resistant animal can be from motherto infant or from an injected serum c Antibodies aka immunoglobulins secreted by activated Bcells or plasma cells have variable antigen binding sites have constant regions on which they are classi ed ve groups providing a binding site for macrophages B cells can create diversity by shuf ing order of gene segments during their development can inactivate and tag for destruction form antigenantibody complexes Defensive mechanisms of antibodies Neutralization antibody blocks speci c sites on viruses Agglutination cellbound antibodies become cross linked and cause clumping Precipitation soluble molecules are linked and then settle out Complement fixation 2 Cellmediated response CD4 TH cells primary helper cells CD8 Tc cells cytotoxic and suppressor cells these cells activate through simultaneous recognition of self and antiself proteins a Antigen recognition two types of MHC proteins are useful Class and Class II MHC Class l are constructed from a base protein and a protein fragment The fragments are either bits of self proteins or foreign products synthesized within the cell such as a viral protein MHC Class proteins are displayed by almost all body cells except blood and are recognized by CD8 cells MHC Class II proteins are typically found on mature B cells CD4 cells and APCs Class II proteins are constructed from a self base and a protein fragment from a foreign body that has been phagocytosed Class and II proteins are important because they alert other cells that the body s cells have been infected b Tcell activation Steps 1 Tcell antigen receptors bind to antigenMHC complex TH CD4 bind to MHC Class II proteins and will mobilize B cells and Tc CD8 cells Tc CD8 bind to MCH Class proteins At this point bound T cells are switched on but are not totally functional These cells are called naive T cells 2 Costimulation Prior to cloning Tcell must recognize other factors Examples include other surface receptors on the APC or cytokines released by macrophages or other T cells Cell will not become functional without costimulation this may help to prevent destruction of own cells that may present a foreign protein due to mutation Once activated T cell divides to produce clones After infection has passed some remain as memory cells c Cytokines proteins secreted by activated T cells and macrophages that act like hormones Some stimulate more rapid cell division Activated T cells also release cytokines Some are toxins others enhance inflammation d Specific Tcell roles Helper CD4 primed by APC presentation of MHC Class II protein stimulate proliferation and cloning of T and B cells that have already become bound to an antigen stimulate activated B cells to divide and produce antibodies Can interact directly with B cells to stimulate them Cytotoxic CD8 inserts perforin into plasma membrane of target Suppressor suppress activity of T and B cells I Diseases A HIV destroys helper CD4 cells over time number ofantibodies declines and CD8 cells do not respond to viral cues long asymptomatic period is not dormancy symptoms occur after lymph node has been destroyed B Autoimmune diseases lymphocytes lose ability to distinguish self from nonself CD8 cells destroy own body cells 1 Multiple sclerosis MS destroys white matter of so and brain 2 Type juvenile diabetes mellitus destroys pancreatic beta cells therefore insulin deficient 3 Rheumatoid arthritis destroys capsule of synovial joint C How does the normal state break down Possibilities 1 Inef cientineffective lymphocyte programming self reactive cells are not selected out in thymus 2 Appearance of new self proteins 3 Crossreaction ofantibodies produced against antigens and self antigens antibody produced binds to similar selfantigens D Hypersensitivity vigorous immune response can be acute subacute or delayed 1 Acute most common is anaphylaXis Steps 1 Contact with allergen stimulates antibody production 2 Many antibodies are produced 3 Antibodies attach to mast cells and basophils 4 Later encounter with allergen 5 Allergen binds and stimulates ood of histamine 6 Result is leaky blood vessels mucus production causes smooth muscles to contract aLocak Cells basic structural and functional unit of living organisms most cells have a nucleus cytoplasm and plasma membrane Plasma membrane defines borders and acts as barrier Fluid mosaic model phospholipid bilayer has hydrophilic heads and hydrophobic tails most membrane proteins have phobic and philic ends integral acts with both sides of membrane involved in transport peripheral attached to integral on inside and outside of cell some are enzymes Plasma membrane functions extract substances from interstitial uid when needed and in right amounts PM is selectively permeable Passive substances that can pass without cell energy Active substances that pass only with help of cell energy Passive processes 1 Diffusion molecules move along or down a concentration gradient selectively permeable 2 Osmosis unassisted diffusion of water moves through pores Osmolarity total concentration of all solute particles in water tonicity ability of a solution to change shape of cell by altering internal H20 volume 1 lsotonic solution whose concentrations of non permeating solutes is equal to what is found in cells 2 Hypertonic solutions with higher concentration than cells these dehydrate 3 Hypotonic solutions with lower concentration than cells these hydrate Facilitated diffusion process where carrier molecules combine with non penetrating molecules then release them into cytoplasm does not need ATP Active Processes 1 active transport solute pumps move particles m concentration gradient uses ATP 2 Vesicular transport used for large particles or macromolecules need ATP Exocytosis substances moved to outside of cell kept in membranous sac that fuses with PM Endocytosis enters cells as membrane surrounds membrane pinches off to form vesicle phagocytosis cytoplasm expands and flows around sac formed is called phagosome bulkphase endocytosis minute droplets of intersitial fluid are taken in receptormediated endocytosis cell binds to specific molecule Cytoplasm material inside PM contains cytosol organelles inclusions Organelles Mitochondria Ribosomes Endoplasmic Reticulum Golgi Apparatus Lysosome Peroxisomes Nucleus Nucleus contains DNA controls cells largest organelle nucleoplasm jellylike substance holds chromatin and nucleoli Nuclear membrane two bilayer phospholipid membranes outer membrane is continuous with rough ER membranes may fuse causing pores selectively permeable but less so than the plasma membrane Nucleoli made ofribosomal RNA rRNA not bound by membrane produce ribosomes rRNA is combined with proteins to form ribosome subunits that pass out pores Chromatin network of DNA fibers throughout nucleus periodically wind around histone proteins to form nucleosomes changes in the shape of histones in a nondividing cell exposes genes that will determine which proteins will be produced When cell prepares to divide chromatin coils to form chromosomes this avoids entanglement and breakage of DNA Cell life cycle 2 major periods 1 lnterphase cell grows and carries out usual functions 2 Mitotic 7 when the cell divides into two cells lnterphase metabolic Subphases 1 G1 metabolically active rapid protein synthesis centrioles begin to appear at the end 2 S synthetic DNA replicates histones are made and assembled into chromatin 3 G2 enzymes and proteins for division are synthesized and move to cell parts centrioles are complete cells that have stopped dividing G0 subphase DNA replication 1 DNA helices uncoil from the nucleosome 2 A helicase enzyme untwists the helix breaks H bonds and separates DNA into two complimentary strands this occurs at multiple locations along the DNA at sites called replication bubbles Y shaped regions at the end of the bubble is called a replication fork 3 Each freed nucleotide serves as a template for building a new complimentary strand Always Adenine bonds with Thymine Guanine bonds with Cytosine 4 Short segments of DNA are joined by DNA ligase ea new DNA molecule has 1 old strand and one new strand semiconservative replication 5 When replication ends histones associate with DNA and the chromatin condenses to form chromatids that are united by a centromere Control of Cell Division poorly understood but surfacevolume relationships are important Amount of nutrients needed is directly related to its volume Ce volume can increase significantly with only relatively minor changes in surface area therefore PM inadequate for nutrient exchange when cell reaches critical size could also be related to contact inhibition cells stop dividing when they touch other cells Cell cycle control at the G2 checkpoint a class of proteins called cyclins accumulate in the cell during interphase Enzymes called Cdk proteins are activated by binding to cyclins to form a substance called maturation promoting factor MPF MPF allows the cell to pass the checkpoint and enter mitosis MPF also begins the breakdown of its own cyclin by the end of mitosis M or Mitotic stage Consists oftwo events 1 mitosis or meiosis 2 cytokinesis Mitosis Early prophase chromatin condenses to form chromatids chromosome is formed through joining two sister chromatids nucleoli disappear mitotic spindle begins to form Late prophase nuclear membrane fragments centrioles move to poles mitotic spindle forms microtubules attach to the centromere Metaphase chromosomes line up at equator to form the metaphase plate Anaphase chromosomes split each chromatid now becomes a chromosome microtubules not attached to chromatids push against each other to push the poles apart and elongate the cell process is assisted by the fact that the chromatin is condensed Telophase and cytokinesis chromosomes uncoil nuclear membrane forms from rough ER nucleoli reappear during cytokinesis microfilaments at the periphery contract to form a cleavage furrow Protein synthesis sole function of DNA is to determine structure of proteins only gene a section of DNA that carries instructions for one polypeptide chain ea sequence of three nucleotide bases is called a triplet can be thought of as a quotwordquot for a specific amino acid eg triplet AAA calls for phenylalanine CCT calls for glycine exon portion of DNA used in coding protein intron portion of DNA not used in coding RNA all RNA types are formed by DNA and assist by decoding DNA and serving as a messenger for protein construction RNA differs from DNA Single stranded 1 2 Ribose sugar 3 Uracil U replaces thymine T as a base RNA types Transfer RNA tRNA carries amino acids Ribosomal RNA rRNA forms the structure of ribosomes Messenger RNA mRNA encodes the information in DNA and provides a template for protein construction Transcription the transfer of information from a DNA gene s base sequence to the complementary base sequence of an mRNA molecule Making mRNA 1 A transcription factor binds to a DNA site near the start sequence 2 The transcription factor assists the binding of RNA polymerase 3 RNA polymerase opens the DNA helix and separates the strands The DNA strand that is the template for mRNA is called the sense strand 4 For each triplet on the DNA strand a corresponding triplet on mRNA is called a codon each amino acid is coded for by multiple codons Translation afterthe mRNA is constructed is leaves the nucleus and enters the rough endoplasmic reticulum 1 A small ribosomal subunit binds to mRNA 2 tRNA attached to the amino acid methionine bindsto mRNA and stimulates the binding ofa large ribosomal subunit this completes the construction of a functional ribosome the functional ribosome has an A site forthe incoming tRNA a P site for the tRNA holding the growing polypeptide protein and an E site forthe exiting tRNA 3 The ribosome holds the tRNA and the mRNA tightly togetherto insure the proper positioning of amino acids 4 The ribosome slides along the mRNA one codon at a time bringing the next codon into the A site to be read by tRNA 5 The chain of amino acids on the tRNA in the P is transferred to the amino acid on the tRNA in the A site by the formation ofa peptide bond 6 At this time the ribosome moves along the mRNA to the next codon at the same time the tRNA in the A site is moved into the P site and the tRNA that was previously in the P site is now moved to the E site and ejected from the ribosome several ribosomes will attach to the mRNA and each will begin to construct a protein This is referred to as a polyribosome mRNA strand is continuously read until it reaches a stop codon such as UGA or UAA and the nished structural or functional protein is released from the ribosome KINS 2532 Learning Outcomes Test 2 Topic 4 The blood Gross 8 microscopic anatomy of the blood 1a Three major functions of the blood 0 Distribution 0 Supplies 02 from lungs to cells 0 Supplies nutrients from GI tract to cells 0 Transports metabolic wastes from cells 0 Transports hormones to target tissuesorgans 0 Regulation 0 body temperature 0 pH of body fluids 0 blood volume to support efficient circulation 0 Protection 0 Prevents blood loss 0 Prevents infection through the activity of white blood cells complement and antibodies 1b Chemical and physical characteristics of blood 0 Chemical pH 735745 Maintained by buffers lungs kidneys bicarbonate phosphate and protein systems 0 Physical o Viscosityresistance to flow Determined by red blood cells RBC and albumins Whole blood is 4555 times more viscous than water o Colo cd U 39 Lerial deep cd bluc 39 U 39 venous o Osmolarity total molarity ofdissolved particles Determined by proteins RBC and sodium ions 1c Two major components of blood 0 Plasma liquid part of blood 55 of blood 0 Contains I Water I Hormonesenzymes I Nutrients I Electrolytes I Respiratory gases I Wastes I Proteins for clotting viscosity transport etc o Formed elements cells and cell fragments 45 of blood NOTE Since most of them are red blood cells it is the value of hematocrit 0 Includes I Erythrocytes I Platelets I Leukocytes ldBlood plasma vs serum Plasma is a mixture of water proteins nutrients electrolytes nitrogenous wastes hormones and gases When the clotting proteins are removed the remaining fluid is serum 1e Plasma proteins 0 Albumin 60viscosity and osmolarity 0 Globulin 36antibodies transport 0 Fibrinogen 4clotting all are synthesized in the liver except for gamma globulins which come from plasma cells Erythrocytes red blood cells 1a Site of formation is red bone marrow from hemocytoblast which multiplies continuously to produce ALL formed elements of blood including RBC 1b On average 46 million erythrocytes in blood streamadult 1c Physical characteristics of erythrocytes 0 Shape discshaped cell with thick rim 0 Composition33 of cytoplasm is hemoglobin Hb 0 Life span 120 days 0 Organelles little U quot lack 39 39 during 39 0 Functions gas transport contributes to blood viscosity 1d Four major changes erythrocytes undergo during erythropoiesis Hemocytoblast9 Erythroblast Reticulocyte9Erythrocyte 0 Loses nucleus 0 Increases in number 0 Decreases in size 0 Produces Hb 0 Reticulocye a young RBC with a well developed endoplasmic reticulum and ribosomes that produce Hb 1e Erythropoiesis is stimulated by the hormone erythropoietin EPO secreted in response to Hypoxemia oxygendeficiency in the blood by kidneys and liver mostly The negative feedback mechanism will stimulate erythropoiesis Stimuli are high altitude loss of blood increased trainingexercise blood doping 2a Structure and function of hemoglobin A molecule Hemoglobin A HbA is adult hemoglobin It contains four globin chains 2 alpha chains and two beta chains Each chain is chain has a nonprotein moietypart called the heme group which binds oxygen to Fe2 at its center Each heme can carry one molecule of 02 this means up to 402 for one molecule of Hb Some C02 in bloodstream is also transported by hemoglobin but by the globin moiety instead o Oxyhemoglobin when one or more molecules of 02 are bound to heme group of hemoglobin o Deoxyhemoglobinwhen hemoglobin loses some of the oxygen bound to it 0 Carbaminohemoglobin when carbon dioxide binds to amino groups of Hb 2b Breakdown of hemoglobin Hemoglobin is broken down into its globin and heme parts moieties The globin is hydrolyzed into its free amino acids which are reused The heme is broken down into its Fe2 and organic components The Fe2 is recycled or stored transferin and gastroferitin are transport proteins ferritin is a storage ironprotein complex The heme group is released and is broken down into biliverdin THEN bilirubin bile pigments which are excreted 3 Differences between hematocrit polycthemia and anemia o Hematocrit percent of formed elements in blood but mostly RBC normal is 45 depending on gender 0 Polycthemia excess of RBC Can be caused by cancer of erythropoietic cell line in the red bone marrow dehydration emphysema high altitude or physical conditioning or by blood doping 0 Anemia low oxygencarrying ability of the blood Can be caused by insufficient number of cells low hemoglobin content or abnormal hemoglobin Symptoms include fatigue paleness and shortness of breath Leucocytes white blood cells 1a Site of formation is red bone marrow from hemocytoblast which multiplies continuously to produce ALL formed elements of blood including WBC 1b Physical characteristic of leucocytes 0 Organelles retain organelles throughout life Are TRUE complete cells 0 Life spanvaries depending on type hoursyears o Functionsdefense against infectious microorganisms and other pathogens 1c Factors that stimulate leucopoiesis production of white blood cells Leucopoiesis begins with pluripotent stem cell hemocytoblast which then can differentiate into all types of WBC The production of WBC is stimulated by CSF and IL produced by macrophages and T cells 1d Five types of leucocytes o Granulocyte HAS granules in cytoplasm o Neutrophils 60 to 70increase in bacterial infections Release antimicrobial chemicals 0 Eosinophils 2 to 4increase in parasitic infections and allergies Release enzymes that weaken or destroy parasites o Basophils lt051increase in allergies Release histamine and heparin o Agranulocyte NO granules in cytoplasm o Lymphocytes 25 to 33increase in diverse infection and immune responses Destroy cancer cells cells infected with viruses and foreign cells Secrete antibodies and serve in immune memory T cells and B cells 0 lVlonocytes 3 to 8increase in viral infections and inflammation Differentiate into macrophages and activate other cells of immune system 0 Order ofabundance most to least Never Let lVlonkeys Eat Bananas 1e Differential count of leucocytes is important because looking at the concentration of each type of leucocytes can tell what kind of infection the patient has For instance if there is an increased amount of Eosinophils in the bloodstream then it is likely that there is a parasitic infection 2 Leucocytosis leukemia leucopenia o Leucocytosishigh WBC count for fighting infections allergies and parasites 0 Leukemiahigh WBC count caused by cancer of hemopoietic tissuebone marrow o Leucopenialow WBC count caused by either poisoning infectious diseases or drugs Thrombocytes Platelets 1a Site of formation is red bone marrow from hemocytoblast which multiplies continuously to produce ALL formed elements of blood including platelets 1b 130000 to 400000 thrombocytes in bloodstream 1c Physical characteristics 0 Life span10 days 0 Organellesno it was never a true cell 0 Functionclotting secrete chemicals to promote vascular spasm and clotting attract other thrombocytes to site of injury and initiate the intrinsic pathway of blood clotting 1d Factors that stimulate thrombopoiesis production of platelets Under the influence of thrombopoietin from the liver or kidney hemocytoblasts turn into megakaryoblasts DNA is duplicated until it becomes a megakaryocyte which gives off fragmentsthrombocytes They never were true cells Hemostasis 1a Three phases 0 Vascular spasmblood vessels constrict to reduce bleeding Can be caused by injury to vascular smooth muscle Chemicals such as serotonin are released by platelets and endothelial cells Platelet plug formation platelets adhere to exposed collagen fibers of the vessel wall to reduce or stop minor bleeding 0 Blood clotting coagulation blood clot forms as platelets become enmeshed in fibrin threads 1b Importance of first two phases 0 Vascular spasm allows time for platelet plug formation and blood clotting Platelet plug formationAs platelets aggregate they undergo degranulation the exocytosis of their cytoplasmic granules and release of factors that promote hemostasis They release serotonin a vasoconstrictor ADPwhich attracts other platelets to the area and stimulates their 39 g 39 39 and 39 39 39 Ithat promotes aggregation degranulation and vasoconstriction This is important because it activates a positive feedback mechanism that can quickly seal a small break in a blood vessel A2 an 1c Coagulation Coagulation multistep process that transforms blood from liquid to gel and is dependent on factors of coagulation Final product is fibrin Extrinsic pathway outside blood itself initiated by factors released by tissuestissue thromboplastin Involved in damaged vessels Takes seconds Intrinsic pathway found inside blood initiated by plateletsplatelet releasing factor Involves platelet degranulation Takes minutes Both use Ca2 Both pathways happen together Intrinsic pathway takes longer than extrinsic pathway due to having more steps before factor Xthrombokinase Two pathways are different till formation of factor Xthrombokinase but then both pathways have same final steps see 1 d 1d Final steps of coagulation Once factor X is activated it combines with other factors to produce prothrombin activator enzyme Prothrombin activator converts prothrombin plasma protein into thrombine an enzyme Thrombin converts fibrinogen a soluble plasma protein into fibrin the insoluble protein Fibrin is used to create the framework of a clot Fibrinolysisbreaking down and removing unneeded clot Plasminogen plasmin dissolves the fibrin 1e Clotting Can be accelerated inappropriate clotting see 1f immobility burns atherosclerosis Can be slowed down 0 In thrombocytopenia In hemophilia genetic lack of certain clotting factors Liver disorders insufficient vit K and other factors of coagulation Anticoagulants factors that inhibit clotting I Heparin a natural anticoagulant which prevents clot formation by inhibiting thrombin formation I Sodium citrate an agent used on glassware and instruments to prevent coagulation by tying up calcium OOO 1f Thrombus and embolus thromboembolytic disorders Thrombus clot developed in an unbroken blood vessel Embolus an abnormal object moving though a blood vessel such as a clot air bubble or lipid droplet ABO Blood typing and Rh factor 1 ABO blood types 0 A has type A antigen agglutinogen and AntiB antibodies agglutinins 0 B has type B antigen and AntiA antibodies 0 AB has both A amp B antigens but no antibodies 0 0 no antigens but both AntiA amp AntiB antibodies Rh Factor is determined by whether or not Rh antigens are present on the cell membranes llRh llmeans there are NO Rh antigens and llRh quot means there are antigens 8 genes can help determine ifa person is Rh positive The most common are CD and E genes Normally Rhquot and Rh blood do not have antiRh antibodies in plasma however Rh can develop these antibodies after the first exposure to Rh antigens 2 Agglutinins are antibodies against red blood cell agglutinogensantigens If someone were to receive the wrong type of blood agglutination would occur due to antigenantibody reactions For example if a RBC has A antigen and AntiB antibodies in plasma Type A blood it will cause agglutination clumping of cells when B antigens in type B and type AB blood come in contact with the antibodies in blood plasma This is why Type 0 blood is the universal donor since it does not have A nor B antigens to react with antibodies in receipients plasma In turn Type AB blood is the universal recipient because it has no anti A and antiB antibodies so it can accept all types of bloodantigens Topic 5 The Endocrine System Organization of the endocrine system 1 General function internal communication and control by means of hormones 2 Hormone chemical messengers that are transported by the bloodstream and stimulate physiological responses in cells of another tissue or organ 0 Free hormone not attached to proteins can have biological effects 0 Carrierbound hormonecannot have biological effects unless drops protein and becomes a free hormone Serve as a reserve and increases half life of hormone 3 target cellorgan the cellorgan acted upon by a hormone or other chemical messenger Hormones can have specificity which means a receptor for one hormone will not bind to other hormones Hormones can also exhibit saturation a condition in which all receptor molecules are occupied by hormone molecules 4 Nervous vs Endocrine system I Nervous system I Endocrine system I Communication through neurotransmitters NT I Communication through hormones NT at synapses distribution Sometimes Reacts to 110 msec Reacts more continue to continuous 5 Negative feedback mechanism importance in regulation of hormone level Reminder negative feedback is a selfcorrective mechanism in which a bodily change is detected and responses are activated that reverse the change and restore stability homeostasisand preserve normal body function In terms of hormone levels negative feedback mechanisms insure homeostasis When the level of hormone is too high negative feedback works to decreases it When the level of hormone is too low negative feedback works to increase it 6 Types of stimuli 0 Humoral stimulihormones secreted in response to blood levels of ions and nutrients 0 PT glands 0 Hormonal stimuli hormones secreted in response to hormones o anterior pituitary gland thyroid gland adrenal cortex ovaries and testes o Neural stimulihormones secreted in response to neural stimuli o Adrenal medulla 7 nvolution shrinkage of a tissue or organ by autolysis such as involution of the thymus after childhood and of the uterus after pregnancy This also occurs in the pineal gland as we get older 8 Other hormone producing structures 0 Heartspecialized cells in atria produce natriuretic peptide ANP which relaxes arterioles inhibits the secretion of rennin and aldosterone also inhibits reabsorption of Na by kidneysincreases Na excretion Reduces BP 0 Kidneys produce e 39 r 39 39 which 39 39 e 39 r 0 Skin produces cholecalciferol which is the vitamin Dhelps absorb more Ca ions in intestine 9 Eicosanoids family of paracrine secretions They have 20carbon backbones derivedformed from a polyunsaturated fatty acid called arachidonic acid in the plasma membrane Cyclooxygenase converts arachidonic acid to three other types of eicosanoids Prostacyclin produced by the walls of the blood vessels where it inhibits blood clotting and vasoconstriction Thromboxanes produced by blood platelets During injury they override prostacyclin and stimulate vasoconstriction and clotting Prostaglandins PGs most diverse with multiple effects Produced in most organs Promote fever and painchemical mediators of inflammation Used for vasodilation or vasoconstriction Individual endocrine glands 1 Pineal gland 0 Location roof of 3rd ventricle in diencephalon lnvolutesshrinksregresses after childhood Hormones secreted melatonin in a circadian cycle Target organs brain possibly gonads Physiological effects timing device for lightdark cycle and mood May regulate timing of puberty through effect on gonads 2 Thymus gland 0 Location mediastinum superior to the heart 0 lnvolutesshrinks o Hormones secreted thymopoietin thymosin thymulin 0 Target organs immune cells T lymphocytes 0 Physiological effects stimulate T lymphocytes developmentmaturation and activity 3 Thyroid gland 0 Location on trachea inferior to larynx 0 Hormones secreted thyroid hormone thyroxine T4 triiodothyronine T3 Target organs most tissues Physiological effects T4 and T3 elevate metabolic rate and heat production increase respiratory rate heart rate accelerate breakdown of lipids and proteins promote alertness and quicken reflexes stimulate growth hormone 0 Hormones secreted Calcitonin Target organs bones intestine kidneys Physiological effects decreases level of Ca ions in 39 39 39 39 39 bone 39 I 39 39 increase in excretion of Ca by kidneys and decrease in ca absorption in intestine 4 Parathyroid gland 0 Location thyroid gland usually posterior to thyroid gland o Hormones secreted parathyroid hormone PTH 0 Target organs bone kidneys small intestine 0 Physiological effects raises blood calcium level by 39 39 39 U bone Irgtu p of bone and inhibiting deposition reducing urinary calcium excretion and enhancing calcitriol synthesis with an increase in ca absorption in the intestines II 5 Pancreas 0 Location inferiordorsal to stomachretroperitoneal o Hormones secreted insulin Beta cells6075 and glucagon Alpha cells 20 0 Target organs muscle adipose tissue primarily liver 0 Physiological effects glucagon stimulates glycogen and fat breakdown to raise blood glucose levels 0 Physiological effects Insulin stimulates glycogen fat and protein synthesis to lower blood glucose levels a Hypoglycemia a deficiency of glucose in the blood Hyperglycemiaand excess of glucose in the blood b Polyuriaexcessive output of urine Polydipsia excessive thirst Polyphagiaexcessive hunger Glycosuria glucose in urine normally glucose is reabsorbed 100 in kidneys and is not detected in urine 6 Adrenal gland two parts overall function to help organism cope with stressful situations location atop the kidneys suprarenal gland Adrenal medullaneural tissue at the center of the gland 0 Hormones secreted epinephrine norepinephrine dopamine 0 Target organs most tissues 0 Physiological effects fight or flight response Adrenal cortexglandular tissue around the medulla 0 Hormones secreted aldosterone cortisol and cur 39 39 Three layers 0 Zona glomerulosa most superficial mineralocorticoids aldosterone Target organ kidney 0 Zona fascicilata glucocorticoids cortisol corticosterone cortisone Target organ adipose tissue liver muscle Zona reticularis gonadocorticoids androgens Target organs bone muscle brain reproductive organs etc 7 Gonads 0 Location ovaries in pelvic cavity 0 Hormones secreted by ovaries o Follicles mostly estrogens esradiol less progesterone 0 Corpus luteum mostly progesterone less estrogens 0 Target organs 0 many tissues reproductive organsuterus mammary glands brain skeletal system 0 Physiological effects 0 quot 39 female 39 39 39 39 r and 39 39 growth regulate menstrual cycle and pregnancy inhibits FSH secretion inhibin 0 Location testes in the scrotum o Hormones secreted by testes o interstitial cells testosterone inhibin 0 Target organs 0 Testes many tissues muscle skeletal system brain reproductive organs anterior pituitary 0 Physiological effects 0 stimulate fetal and r r sperm production and libido inhibits FSH secretion inhibin 39 growth 8 Pituitary gland 0 Structure nfundibulum connects the pituitary gland to HTA superiorly nfundibulum houses the HP system and HH tract Hypophysial portal system HP system network of capillaries connecting the hypothalamus with the anterior pituitary gland Hypothalamishypophysial tract HH tractbundle of nerve fibers that arise from certain cell bodies in the hypothalamus and connect it to the posterior pituitary gland o Posterior lobe neurophypophysisnot a true gland as it is nervous tissue 0 Hormones produced by HTA but stored here I antidiuretic hormone ADH Target organs kidneys Physiological effects water retention oxytocin OT Target organs uterus mammary glands Physiological effects labor contractions milk release 0 Anterior lobe adenohypophisis made of glandular tissue Producesstops own hormones in response to releasinginhibiting hormones from HTA o Hormonestarget organphysiological effect SEE TABLE 9 Hypothalamus a neuroendocrine organ produces o Releasing hormones 5 stimulate pituitary cells to secrete hormones of its own see hormones of anterior pituitary 0 Inhibiting hormones 2 suppress pituitary secretion see hormones of anterior pituitary 0 Concept of axis a number of glands 3 that signal each other in sequence 0 Thyroid axis HTA anterior pituitary thyroid o Adrenal axisHTA anterior pituitaryadrenal gland o Gonadal axisHTA anterior pituitarygonads Examples of homeostatic mechanisms 1 Endocrine glands respond to maintain homeostasis in the body 0 Pineal glandsecretes melatonin which helps us fall asleep Sleep is needed for biological maintenance 0 Thymus secretes hormones for the development of Tlymphocytes We need these T lymphocytes to help with immunity for fighting infections 0 Pancreas secretes insulin and glucagon so help stabilize our blood glucose levels 2 Endocrine system works with other systems to maintain homeostasis mainly through producing hormones These hormones in turn affect target organs that are involved in other body systems see pg 678 in textbook Application of homeostatic mechanisms 1 Factor that could disrupt homeostasis o Tumors can form when there are no controls to stop a cell from dividing The cells can then metastasize and spread throughout the body This can negatively affect tissues and organs of the body preventing them from working correctly Autoimmune diseases when the immune system attacks the body Can destroy cells tissues and eventually organs of the entire body 2 If the endocrine system does not maintain homeostasis diseases and conditions can occur including 0 Hypothyroidism insufficiency of thyroid hormone Has symptoms that are seen in slow metabolism low metabolic rate depression of CNS lethargy weight gain etc Hyperthyroidism Grave s disease It is an autoimmune disease where antibodies activate TSH receptors Symptoms include nervousness weight loss hyperphagia and exophthalmos swelling of extracellular muscle and connective tissue Ex bulging eyes Cushing s diseasesyndrome prolonged increase in plasma glucocorticoids as hypersecretion of cortisol Symptoms include high blood sugar high BP poor wound healing and buffalo hump moon face etc Diabetes mellitusmetabolic disease caused by hyposecretionhypoactivity of insulin or peripheral resistance to insulin Symptoms include polyuria polydipsia polyphagia blurred vision fatigue glycosuria hyperglycemia and ketonuria 0 Type 1 idiopathic and immune mediated Usually occurs before 20 Cannot create enough insulin on own Needs insulin for treatment 0 Type 2 caused by obesity andor family history Usually occurs after 30 Target cells are resistant to insulin Requires oral antidiabetic drugs Pregnancy and Human Development pregnancy events from fertilization to birth gestation period from last menstrual period to birth approximately 280 days from conception to two weeks after preembryo from third to eighth week embryo from ninth week to birth fetus at birth infant Fertilization oocyte is viable for 12 to 24 hours after ovulation most sperm are viable for 24 to 72 hours for fertilization coitus must occur between 5 days before ovulation and 24 hours after only a few hundred sperm may reach the oocyte sperm must be capacitated before they can fertilize acrosome secretions breakdown corona radiata and zona pellucida secretions of many sperm necessary for one to penetrate membrane of sperm merges with oocyte membrane when spermatic membrane contacts membrane of oocyte sodium channels open and depolarize this is the fast block to polyspermy Ca is released into oocyte cytoplasm which activates the oocyte to prepare for cell division Ca in ux also causes the cortical reaction granules just deep to PM empty contents into extracellular space material from granules bind to water and cause cell to swell this causes detachment of any remaining sperm this is called the slow block to polyspermy Ca in ux stimulates oocyte to undergo meiosis H and eject second polar body almost immediately chromosomes merge and replicate Preembgonic development from fertilization to implantation at about 36 hours after fertilization the first cleavage division produced 2 identical cells by 72 hours it has become a mass of cells called a morula mass becomes hollow and fluidfilled and is called a blastocyst zona pellucida breaks down and releases the blastocyst blastocyst cells differentiate into trophoblast an outer flattened layer of cells which will become the placenta inner cell mass an inner cluster of rounded cells that will become the embryonic disc and later the embryo Implantation blastocyst binds to endometrium begins to secrete digestive enzymes cytokines control in ammatory response and growth factors endometrium quickly thickens in that area cells of trophoblast divide and form two layers one layer becomes a multinucleated mass and destroys cells of uterine wall blastocyst becomes further embedded in the uterine wall proliferation of endometrial cells completes this process implantation finished by the fourteenth day after ovulation trophoblast cells secrete human chorionic gonadotropin hCG prompts corpus luteum to continue to produce hormones Placentation originates from both embryonic and endometrial tissues cells from trophoblast form extraembryonic mesoderm on the inner surface this layer of cells becomes the chorion from chorion extend projections called chorionic villi chorionic villi contain blood vessels endometrial blood vessels become leaky and fill intervillus spaces with blood chorionic villi and the decidua basalis together form the placenta embryonic barriers prevent free diffusion of substances from embryonic to maternal blood barriers consist of chorionic villi and endothelium of embryonic blood vessels by second or third month placenta begins to secrete estrogen and progesterone Embryonic development embryonic membranes also form during this time 1 Amnion develops from cells of the embryonic disc becomes filled with amniotic uid provides protection and constant temperature 2 Yolk sac from cells on opposite side of disc forms part of the digestive tube early producer of blood cells and source of primordial germ cells for gonads 3 Allantois forms base of umbilical cord 4 Chorion Gastrulation shortly after implantation blastocyst differentiates into gastrula gastrula contains three primary germ layers of cells by second week postfertilization l Ectoderm 2 Mesoderm mesenchyme 3 Endoderm embryonic disc elongates and develops a ridge down the center called the primitive streak mesoderm cells beneath the streak aggregate to form a rod called the notochord serves as first axial support of embryo embryo is about 2mm long Organogenesis By week 8 all adult organ systems are recognizable first major event is neurulation formation of spinal cord from cells of the ectoderm ectoderm on top of notochord thickens to form neural plate plate begins to fold inward producing the neural groove and neural folds by day 23 neural folds fuse and form neural tube by end of first month three primary brain vesicles are observable by end of second month cerebral hemispheres are present and brain waves can be detected embryo continues to fold to assume a cylindrical shape folds partially surround yolk sac part of sac that is enclosed becomes the primitive gut cells of primitive gut eventually become endoderm of digestive tract mesoderm forms the remainder of digestive organ layers clusters of mesoderm form on either side of the notochord the largest of the clusters are called somites each somite gives rise to a segment in the body wall segment vertebra rib muscle and skin folding of embryo produces the coelom or ventral body cavity Development of fetal circulation the first blood cells arise from the yolk sac during the first two weeks of development spaces appear in mesoderm spaces are lined with endothelial cells covered with mesenchyme and linked together two vessels forming the heart have fused and bent into an S shape by the end of the third week by 35 weeks heart is beating Unigue vascular modifications umbilical arteries and veins vascular shunts umbilical vein carries oxygenated blood from the placenta blood enters liver some blood travels to liver sinusoids and then out through hepatic veins most blood enters ductus venosus bypasses liver entirely to enter the inferior vena cava placental blood mixes with deoxygenated blood from lower extremities and organs blood flows from right atrium to right ventricle or through foramen ovale into left atrium blood from right ventricle enters pulmonary trunk blood in pulmonary trunk is diverted to the aorta through the ductus arteriosus this bypasses the pulmonary circuit blood though aorta eventually reaches umbilical arteries from branches of the external iliac arteries blood does not completely mix blood from inferior vena cava is preferentially diverted to foramen ovale blood from superior vena cava diverts to right ventricle Events of fetal development weeks 9 through 40 period of rapid growth cells continue to differentiate into specific tissue types and structures rapid cranial growth development of limbs lags behind Effects of pregnancy on mother Anatomical changes reproductive organs become increasingly vascularized breasts become engorged with blood some experience increased pigmentation of the skin uterus size increases dramatically placental production of relaxin loosens pubic and sacroiliac ligaments weight gain of approximately 30 pounds usually occurs only require 300 additional calories daily Metabolic changes placenta secretes human placental lactogen hPL to stimulate maturation of breasts for lactation maternal cells metabolize more fatty acids than glucose glucose is spared for fetus placenta also secretes human chorionic thyrotropin which raises blood calcium level Physiological changes acid reflux constipation nausea increased urine production vital capacity and respiratory rate increase residual volume declines as pregnancy continues blood volume increases 2540 cardiac output increases 2040 blood return is impaired Parturition usually occurs Within 15 days of due date 280 days from last menstrual period Fluid and Electrol e balance Electrolytes dissociate into ions in water because they are charged they can conduct an electrical current inorganic salts inorganic acids and bases some proteins electrolytes have ability to cause water shifts Water electrolvte and Acidbase balance Cell function is dependent on a carefully controlled uid medium Life threatening disorders can come from an imbalance in osmolarity electrolyte concentration or pH Three types of homeostatic balance are maintained 1 Water balance 7 ave daily intake and los are equal 2 Electrolye balance 7 amount absorbed in the small intestine equals what is lost 3 Acidbase balance 7 removal of H that equals what is created through metabolism Water balance Body water is distributed among uid compartments 65 as intracellular uid or ICF cytosol 35 as extracellular uid ECF 25 of this as interstitial uid 8 blood plasma and lymph 2 transcellular cerebrospinal bile humors of eye Water moves easily through plasma membranes Osmotic gradients between ICF and ECF don t last long and are driven by relative concentrations of solutes Water gains come from two sources 7 1 metabolic water 2 preformed from ingestion and drinking Water is lost from 7 urination in feces expired breath sweat cutaneous transpiration Regulation of intake Dehydration reduces blood volume and pressure and raises osmolarity The thirst center in the anterior hypothalamus that responds to Angiotensin produced in response to low pressure Antidiuretic hormone released in response to rising osmolarity Signals from osmoreceptors in the hypothalamus Regulation of output Kidneys can only slow effect of dehydration Kidneys cannot replace lost water or electrolytes Water output is primarily controlled by sodium ADH provides a mechanism independent of sodium Stimulated by decline in blood volume and increase in sodium concentration Hypothalamus responds by releasing ADH ADH stimulates cells in the collecting duct to synthesize aquaporins Aquaporins increase permeability to water Volume depletion results when water and sodium are lost in equal amounts Caused by trauma diarrhea Dehydration results when more water than sodium is lost Simplest cause is a lack of drinking water This can be a serous problem for elderly who need someone to bring water to them especially for those who can t express their need or have caretakers who are insensitive to it Infants are at increased risk because Increased metabolic rate requires rapid elimination in kidney Kidneys are not fully developed Greater body surface to volume ratio than adults causes them to lose more water from evaporation From sweating uid is extracted from the blood by secretory cells of sweat glands Blood then removes water from the interstitial uid to balance loss of pressure Fluid excess Volume excess does not effect ratio of water to sodium Caused by renal failure or aldosterone hypersecretion Hypotonic hydration due to more water than sodium is retained or ingested ADH hypersecretion can also cause through excessive water retention Electrol e balance Sodium Adult needs about 5 g per day ave diet provides 3 to 7g per day Fluctuations in sodium concentration directly stimulate the adrenal cortex to secrete aldosterone and renin stimulates release due to hypotension Only cells in DCT and ascending limb have receptors for aldosterone Aldosterone binds to nuclear receptors and activates the transcription of a gene for the NaK Pump In 10 to 30 minutes enough sodium is reabsorbed that it sodium concentration in the urine begins to fall and potassium concentration rises Water and Cl passively follow Na So urine will contain less NaCl and more K and have a lower pH However sodium concentration does not change because a proportionate amount of water is absorbed at the same time Hypertension inhibits the r 39 39 39 J 39 39 so the urine may contain up to 30mg of sodium a day ADH can lower the concentration of sodium by permitting water retention and stimulating thirst A drop in sodium concentration inhibits a release of ADH which leads to water loss Atrial naturetic peptide inhibits sodium and water reabsorption and the release of renin and Thus the kidneys eliminate more sodium and water Estrogen copies aldosterone so during the menstrual cycle increased estrogen leads to sodium reabsorption and then water retention Potassium Regulated by aldosterone along with sodium A rise in K concentration stimulates a release of aldosterone that stimulates renal secretion of K Acids bases and buffers Strong acid 7 ionizes freely giving up most of its hydrogen ions Weak acid 7 ionizes only slightly and retains most of its hydrogen Strong base 7 has a strong tendency to bind to H Weak base 7 binds to less of the available H Buffer 7 resists changes in pH by a strong acid or base into a weak one Physiological buffer 7 a system that stabilizes pH by controlling the body s output of acids bases or C02 Chemical buffer 7 a part of a physiological buffer that uses bicarbonate phosphate or protein Bicarbonate buffer CO2 H20 lt gt HzCO3 lt gt HC0339 H Carbonic acid act as a weak acid to the right Bicarbonate ions act as a weak base to the left Lungs help by removing C02 and keeping the reaction moving to the left Kidneys help by removing HCOg39to lower pH Phosphate buffer H2P0439 lt gt HPO4239 H Most important in the renal tubule and ICF Protein buffers COOH gt COO39 Hl Side groups like carboxyl can release H as pH rises Others have amino NHZ which bind to H NH2 H gt NH3 Respiratog control of pH Addition of C02 to body uids lowers pH Removal of CO2 raises pH Increased ventilation will raise pH Renal control of pH Hydrogen ions are transported from the blood to the ltrate contained within water or carbonic acid yes I know several steps have been omitted below See lecture for explanation 2 C02 and H20 enter the cell 4 Carbonic anhydrase catalyzes formation of HZCO3 5 H2C03 dissociates into HC03 7 and H 6 NalHl antiport transports H to ltrate If pH in ltrate is lower than 45 this reaction will not occur due to equal concentrations of H on either side of cell membrane Bicarbonate ions are ltered by the glomerulus gradually disappear from the ltrate due to process in gure 249 and appear in the peritubular capillary blood Bicarbonate ions are not reabsorbed only C02 is reabsorbed Bicarbonate ions come from step 5 Disorders of acidbase balance Respiratory acidosis 7 buildup of CO2 from poor ventilation Respiratory alkalosis 7 from hyperventilation Metabolic acidosis 7 increased production of organic acids such as lactic acid from anaerobic respiration or ketone bodies from alcoholism or diabetes mellitus KINS 2532 Learning Outcomes FINAL Topic 11 Reproductive system Overview and general organization of the reproductive system MaleFemale depending on 0 Sex organs internalexternal Physiologyhormones 0 Chromosomes XX or XY 0 Secondary sex characteristics 0 Anatomy 0 Gender identity 0 Gender rolebehavior 1 Major functions female 0 Makes and transports egg and supports zygote produces hormones o Meiosis l is not completed until menstruation and meiosis II is not complete until fertilization 0 FSH and LH directly regulate ovarian cycle 0 Follicles are induced by FSH and their cells support the oocyte 0 LH induces completion of meiosis 1 to make the secondary oocyte 0 Corpus luteum becomes progesteronesecreting o Progesterone and estrogen directly regulate the uterine cycle 0 Progesterone prepares the breasts and endometrium o Estrogen increases and progestins decrease GnRH gondotropin releasing hormone pulses 0 No direct connection between uterine tubes and ovaries 2 Organization of female reproductive system 0 Primary sex organsgonads o Ovaries internal 0 Secondary sex organsaccessory organs 0 Vagina internal Uterus internal Uterine tubes internal OOO Vulvapudendum external 3 Mitosis vs Meiosis Mitosis Meiosis Where occurs Everywhere in the body Only gonads ovaries and testes Used for Growth embryonic growth tissue repair Produces gametes egg and sperm of cell divisions 1 preceded by DNA replication 2 only the first one is preceded by DNA replication of daughter cells 2 genetically identical 4 not identical Chromosome in daughter cells 46 23 Particularities of DNA replication Chromosomes do NOT change genetic makeup In early stages chromosomes of each homologous pairjoin and exchange portions of DNA During prophase 1 the homologous chromosomes form pairs called tetrads Chromatids often break and exchange segments crossing over This creates new combinations of genes to make genetic variety 4 Internal vs External female genitalia see 2 5 Anatomical boundaries of the perineum Made up of 3 muscle layers that span the pelvic outlet and support the pelvic viscera Has a diamond shape divided into two triangles urogenitalanterior and analposterior 0 Anterior boundary 0 Pubic arch 0 Lateral boundaries 0 schial tuberosities 0 Posteriorboundary o Coccyx 6 Components of the vulva o Mons pubis 0 fat overlying the pubic symphysis covered with pubic hair at puberty 0 Labia majora 0 thick folds of skin and fat covered with pubic hairs o Labia minora o medial thin hairless folds 0 form vestibule has the urethral and vaginal orifices 0 form hoodlike prepuce over clitoris 0 Clitoris o Erectile sensory organ 0 Homologous to glans penis of male 0 Glans and courpus I no corpus spongiosum o Crura attach it to the pubic symphysis 0 Vestibular bulbs 0 Areas of erectile tissue around the vagina 0 Paraurethral greater and lesser vestibular glands 0 Open into the vestibule for lubrication of vagina secrete mucus 7 Components and functions of mammary glands specialized organs of the integumentary system 0 Areola darker pigmented area that surrounds the nipple Together make conical body of breast o Lobes subdivided into lobules 0 Suspensory ligaments attach breasts to muscle and skin 0 AlveoliLactiferous ductsLactiferous sinuses are part of milk producing apparatus 0 Lactation synthesis and ejection of milk from the mammary glands Function produce milk for nourishment If not lactating contains a system of branching ducts and fat tissue Size of breasts is dependent on amount of fat tissue Internal reproductive organs 1 Ovaries 1a Function to produce the oocyte female gamete and hormones estrogen and progesterone 1b location medial pole of ovary is attached to the uterus by the ovarian ligament and the lateral pole of the ovary is attached to the pelvic wall by the suspensory ligament has ovarian artery and vein Anterior margin of the ovary is anchored by a peritoneal fold called the mesovarium The tent like ligament called broad ligament tents the uterus and supports the uterus uterine tubes and vagina It also forms the suspensory ligament and mesovarium 1c Components of the ovary 0 Tunica albuginea covers the ovaries externally o Cortex produces the gametes and contains the ovarian follicles 0 Egg is protected by follicle estrogen and progesterone are produced inside of the ovarian follicles Medulla lrnner layerlr eontarnstne plood yessels and henES 1 Compare pnrnary oozvtss stops at propnase l rnerosrs untrl puberty At n ooevte s formsd Seeondarv oomssformsd wrtn tnenrst polar rate depends on fEnlllzatlorl V fsnlllzsd nnrsnes rnero not dres off Folllzular allss slngle layer ofsquamous eells Granulose allss stratmed granulose eells eloprnent offolllzl pey e Prlmordlal folllzless many at prrtn eontarns a pnrnary ooeyte and a srngle layer ofsquamous folllzular eell Prlmal v folllzlss enlarged ooevte and a srngle layer of eupordal ne a more enlarged ooevt z or more layers e d Granulosa eells seerete zona pelluerda and Mature folllzlE Graan39 one seeondarv folllzle nereased n sue pulges out from tne Merosrs H started Has antrurn lled wrtn folllzular uld Surfazs of oyary Corpus lutgumr rernarns ofthg folllzle attne srte of oyulatron seeretes rnostly progesterone put also lttle estrogen and tnen degenerates pody wnren dres ll V I8 III I Primordial lollicle Q No change a birth In manopauss primary lallIcla Granulosa 7 cells Ann39um 1 acme Granulosa cells at srte of oyulatron z uterrne tubes 23 Furlztlorls passageway rortne oocvte and srte of fsrtllizatlorl n teru s lgarnent 2e ComDon tne u g ofthe proad 0 nfundibulum trumpet like shape Ampulla middle and longest part of the tube 0 Isthmus narrower part of tube leads to uterus 2d Histology of uterine tubes consists of the mesosalpinxoutside layer smooth musclemiddle layer and ciliated mucosa inner layer with nonciliatedsecretory cells The cilia beat toward the uterus and help with muscular contractions of the tube conveying the egg in that direction 2e Ectopic pregnancy pregnancy that takes place anywhere outside the uterus Mostly occurs in the uterine tubes but can happen in pelvic cavity 3 Uterus 3a Functions 0 Passageway for sperm 0 Receives the blastocystusual site of blastocyst implanatation 0 Retains and nourishes the fetus 0 Expels the fetus at term 3b location and support mechanism 0 Broad ligament 0 A pair of uterosacral ligaments attach the posterior side of the uterus to the sacrum and a pair of round ligament arise from the anterior surface of the uterus pass through the inguinal canals and terminate in the labia majora The cervix and superior part of the vagina are supported by cardinal ligaments extending to the pelvic wall 0 Rectouterine pouch a recess between the uterus and rectum 0 Vesicouterine pouch between the urinary bladder and uterus 3c Components of the uterus Body midportion Fundus broad superior curvature 0 Cervix cylindrical inferior end Cervical canal narrow passage in cervix in which lumen communicates with the vagina Two openings 0 Internal os opening into the uterine cavity 0 external os opens into the vagina 3d Differentiate between 0 perimetriumexternal layer of the uterine wall 0 myometrium middle muscular layer 3 4 4 4 o endometrium inner mucos layer 0 cervical glands secrete mucous used for lubrication change under influence of estrogen and progesterone e 2 layers of endometrium 0 functional layer shed during menstruation due to decrease in estrogen and progesterone and ischemia of endometrium Spiral arteries constrictspasm when estrogenprogesterone levels decrease at the end of the cycle causing endometrial ischemia and necrosis Pools of blood accumulate on the stratum functionalis which is then shed 0 basal layer layer that is kept during menstruation and will help rebuild new functional layer Vagina a Functions 0 female organ of copulation 0 receives penis and semen 0 serves as birth canal 0 passageway for menstrual flow b location and particularities location lies between the rectum and the urinary bladder made up ofadventitiaexternal muscularis middleand a mucosa internalwith stratified squamous in adults epithelium with transverse ridges called rugae NO glands Acidic pH in adult females nonspecific defense At vaginal orifice the mucosa folds inward and forms the hymen which stretches across the opening Present until first intercourse Hymen has 1 opening to allow menstrual flow to pass through but it must be ruptured for intercourse to take place Physiology of the female reproductive system 1 Terms Puberty the development of the reproductive system starting with the secretion of hormones by the hypothalamus GnRH Menarchethe first menstrual period at puberty usually occurs around age 12 Pubarchethe development of pubic and axillary hair also the apocrine and sebaceous glands Amenorrhealack of menstruation Menopause the midlife change in hormone secretion in women is accompanied with menopause which is the cessation of menstruation o Hormone replacement therapylow doses of estrogen and progesterone used to replace the hormones NOT produced after menopause 2 28day ovarian and uterine cycle Happen in parallel Events in uterus not possible without events in ovaries 2a Phases OVARIAN Follicular phase from menstruation to ovulation characterized by development of follicles and oocytes Most variable part of the cycle hard to predict date of ovulation s divided into menstrual phase and preovulatory phase The 25 primary oocytes that were formed on day 25 of the previous cycle are transformed into secondary follicles GnRH levels high FSH and LH levels high Follicles and oocytes are developing but only one usually will achieve a mature Graafian stageOvaries secrete mostly estrogen UTERINE A series of changes in uterus under the influence of ovarian hormones Also called the menstrual cycle Involves the endometrium First halfof cycle is divided into menstrual phase and proliferative phase 0 Menstrual phase Blood serous fluid endometrial tissuefunctional layer and fibrinolysin are discarded About 40 ml of unclotted blood and 35 ml of serous fluid 0 Proliferative phase growth of the endometrium of the basal layer by mitosis due to estrogen Development of progesterone receptors on the endometrial cells OVULATIONtriggered by LH midcycle short process in which secondary oocyte is expelled from Graafian follicle into pelvic cavity to be picked up by fimbriae The spike in LH is due to an increase in estrogen from the follicles An increase in blood flow to the follicles causes them to swell rapidly collagenase weakens the walls of the ovary and fluid flows out of the Graafian follicle with the secondary oocyte which is swept up by the fimbriae into the uterine tube OVARIAN Postovulatary phase second half mostly regulated by corpus luteum secreting high levels of progesterone s divided into luteal and premenstrual phases 0 Luteal phase corpus luteum is formed at site of ovulation from the ruptured follicle under the direction of LH INCREASE in progesterone stimulates the secretory phase of the menstrual cycle 0 Premenstrual phases if pregnancy does not occur the corpus luteum becomes the corpus albicans which causes a DECREASE in progesterone leading to menstruation Spiral arteries constrict causing endometrial ischemia and necrosis as discussed in section 3e of internal reproductive organs UTERINEMENSTRUAL Second half of cycle is divided into secretory and premenstrual phases and is mostly regulated by corpus luteum o Secretory phase o thickening of the 39 39 due to r C that 39 39 glands to secrete glycogen Functional layer is thickening because ofaccumulation of fluid NOT DUE TO MITOSIS 0 Premenstrual phase o If pregnancy does not occur the corpus luteum in ovaries becomes the corpus albicans by the beginning of the next ovarian cycle which causes a DECREASE in progesterone leading to menstruation Pools of blood accumulate on the stratum functionalis which is shed during menstrual phase of next cycle 2b Hormonal control of the ovarian cycle Hypothalamus pituitary ovaries9 uterus 0 Step 1 Gonadotropin releasing hormone GnRH from hypothalamus 0 Step 2 GnRH stimulates the anterior pituitary lobe to produce FSH and LH 0 Step 3 FSH and LH directly stimulate the ovarian cycle 0 FSH leads to the development of follicles and release of estrogen o LH stimulates ovulation and leads to the development of the corpus luteum and release of progesterone o Estrogen and progesterone directly stimulate the menstrual cycle 3 28day menstrual uterine cycle 3a Events that occur during uterine cycle See 2a 3b Hormonal control of the menstrual uterine cycle the follicles produce estrogen which stimulates the uterus to replace its endometrium through MITOSIS The corpus luteum produces progesterone which stimulates the uterus to replace its endometrium by secretions and fluid accumulation First half of cycle ovaries produce mostly estrogen high levels second halfmostly progesterone high levels 4 Physiological effects of estrogen and progesterone SEE TABLE ON HORMONES Overview and general organization of the male reproductive system 1 Functions Makes stores and delivers semen PRODUCES hormones The testes are the source of sperm cells and androgens The scrotum is outside the body to cool the testes o Spermatogenesis involves mitosis meiosis and spermiogenesis 0 The vas deferens pumps spermatozoa to prostate o 3 accessory glands add fluids necessary for sperm function reproductive health 0 The penis is a hydrostat and is NOT stiffened by muscular contraction o FSH and testosterone promote spermatogenesis and hormonal negative feedback to FSH releasing pituitary via inhibin 0 LH induces testosterone and is limited by negative feedback to hypothalamus via testosterone 2 Organization 0 Primary sex organsgonads O Testes 0 Secondary sex organsaccessory organs 0 O O Penis Ducts Glands 3 Internalexternal male genitalia 0 Internal 0 O O O O Testes Epididymis Ductus vas deferens Ejaculatory duct Spermatic cord 0 External 0 O 4 Define Penis Scrotum 0 Cryptorchidism undescended testes testes at different levels in abdominal cavity 0 Vasectomy cutting the vas deferens so that sperm cannot be transported to the prostate Male birth control 0 Impotence erectile dysfunction the inability to fertilize an egg Sterility infertilityinability to reproduce 0 Circumcision removing the prepuce or foreskin on the penis Male reproductive organs 1 Testes 1a Functions to produce testosterone and sperm 1b location and blood supply Testes are located in the scrotum The scrotum is a pouch of skin or superficial fascia that holds the testes It is separated into two compartments by the median septum The spermatic cord arises from the scrotum and enters the abdominal wall through the inguinal canal The spermatic cord holds the testicular arteries veins nerves and lymphatic vessels 1c Thermoregulation of testes o Pampiniform plexus formed by a network of testicular veins surrounded by testicular arteries and is important for thermoregulation of testes The testicular veins ascend near the testicular arteries which are branches of the abdominal aorta o This countercurrent exchange cools the arterial blood as it descends into the testes The arterial blood cools as it descends because the venous blood takes the heat from it while it rises o Dartos muscle smooth muscle that wrinkles the skin to decrease the surface area of the scrotum 0 Cremaster muscle segments of the internal oblique that pulls the testes toward the body to warm them 1d Histology of the testes 0 Tunica vaginalis outer tunic of the testes descended into the scrotum with the testes 0 Tunica albugineawhite fibrous capsule with septa dividing the testes into lobules o Lobules house the seminiferous tubules lined with a thick germinal epithelium composed of germ cells at different levels of development Drain into rete teses Interstitial cells located in the septa and produce the testosterone O Sustentacular cells located in the seminiferous tubules and aid with the development of 0 sperm support germ cells and form BT barrier o Efferent ductules 12 small ciliated ducts that collect sperm from the rete testes and transport it to the epididymis 1e Spermatogenesis vs spermiogenesis Spematogenesisthe production of sperm that happens during pubertyincludes spermiogenesis 0 Type A spermatogonia will remain outside the BTB bloodtestesbarrier and produce daughter cells through mitosis until death 0 Type B spermatogonia are the cells that will become the sperm and travel across the BTB inward toward the lumen tight junctions are formed behind them 0 Will undergo meiosis to become a primary spermatocyte a secondary spermatocyte and then a spermatid 0 Spermiogenesis is the final cellular changestransformation that turn spermatids into spermatozoa This is when excessive cytoplasm is discarded and it grows a tail 1f importance of spermatozoa The acrosome contains enzymes that are later used to penetrate the egg if the sperm is successful The mitochondria produce ATP needed for the beating of the tail when the sperm migrates up the female reproductive tract 1g BTB Bloodtestesbarrier Components made out of sustentacular cells with tight junction Function prevents antibodies from reaching the sperm because the antibodies would identify the sperm as foreign and destroy it 2 Male ducts 2a Epididymis 0 Locationon posterosuperior surface of testes 0 Particularities of structure Is a highly coiled duct that has a head body and tail 0 Functionsite for sperm maturation and storage 2b Vas Deferens 0 Location 45 cm muscular tube that passes from the scrotum to the posterior surface of the bladder o Particularities of structure 0 Ampulla exhibits peristalsis during orgasm 0 Functioncontraction of the smooth muscle moves the sperm from the epididymis to the prostate 0 Ligated in vasectomy 2c Ejaculatory ducts 0 Location2 cm long cord formed from the ampulla of vas deferens and seminal vesicles Passes through prostate and empties into the urethra 0 Particularities of structurefunction passes through prostate empties into urethra 2d Urethra 0 Locationin prostate urogenital diaphragm penis 0 Particularities of structure 20 cm long 3 parts 0 Prostatic o Membraneous o Penilespongy 0 Functionexcrete urine and passageway for semen 3 Accessory glands 3a Seminal vesicles 0 Location posterior to the bladder 0 Particularities of structure Empty into ejaculatory duct 0 Functionproduce 60 of seminal fluid 3b Prostate gland 0 Locationbeneath the bladder and encircles the urethra and ejaculatory duct 0 Particularities of structureproduce prostatespecific antigenused for detection of prostatic cancer 0 Functionproduces 13 of semen 3c Bulbourethral glands 0 Locationnear bulb of penis o Particularities of structureempty into penile urethra 0 Functionproduces a lubricating fluid to neutralize the acidic pH First fluid to be produced 4 Penis 4aFunctionmale copulatory organ Delivers the sperm into the female reproductive tract Homologue to the female clitoris has erectile tissue 4b Particularities of structure external portion is 4 in long when flaccid 0 Internal root 0 Visible shaft 0 Glans penis 0 Prepuce foreskin allows expansion 0 3 erectile tissues 0 Corpus cavernosum paired and diverge like the arms of a Y The crus of the corpus cavernosum is attached to the pubic arch and is covered in ischiocavernosus muscle 0 Corpus spongiosum single and extends along the ventral side of the penis I Encloses the penile urethra and ends as a dilated bulb ensheathed in the bulbospongiosis muscle Physiology of the male reproductive system 1 Physiological effects of testosterone SEE TABLE 2 Male reproductive function 2a Hormonal regulation of the male reproductive system 0 As hypothalamus matures it begins producing GnRH o Triggers male reproductive function at puberty and stimulates the anterior pituitary to produce FSH and LH o LH stimulates the interstitial cells of the testes to secrete testosterone o FSH stimulates the sustentacular cells to a protein called androgen bindin protein ABP into the lumen of the seminiferous tubules o ABP raises the testosterone level in the tubules and the epididymis by binding and accumulating the hormone 0 The body can modulate FSH secretion and sperm production without having to reduce LH and testosterone secretion 0 The mechanism for this is a hormone called inhibin secreted by the sustentacular cells if the seminiferous tubules o nhibin selectively suppresses FSH output from the pituitary N U Male sexual response 0 Erection Parasympathetic reflex PS refelex with nitric oxide NO release in response to thoughts visual or auditory signals direct sensory stimulation of penis or both When NO is present it stimulates the production of cGMP that dilates the arteries in the penis The deep artery of the penis dilates erectile tissue becomes engorged and the penis becomes erect Then the bulbourethral gland secretes bulbourethral fluid 0 Ejaculation Sympathetic reflex 0 Emission Seminal vesicles and the prostate gland secrete their components of the seminal fluid the ductus vas deferens goes through peristalsis which moves the sperm into the ampulla The ampulla contracts and moves sperm into the urethra point opf no return Ejaculation will happen and should not be stopped Internal urethra orrifice closes to prevent passage of urine into urethra o Expulsion ejaculation of semen The prostate gland and seminal vesicles secrete any additional components they have then the bulbocavernosus and ischialvacernosis contract the root and bulb of the penis are compressed rhythmically and the sperm s ejected Orgasm can accompany ejavulation 15 sec long reaction of pleasure 2c Role of PS and S systems in erection and ejaculation 0 Erection autonomic reflex mediated by parasympathetic nerve fibers 0 Fibers trigger secretion of nitric oxide which leads to the relaxation of the deep arteries and the lacunae 0 Ejaculation2 stages reflex mediated by sympathetic nerve fibers and somatic influences 0 Emission when sympathetic nervous system stimulates peristalsis in the smooth muscle of the ductus vas deferens and sperm is transported into ampulla o Expulsion when semen in the urethra activates somatic and sympathetic reflexes M Components formed elements erythrocytes RBC leukocytes WBC platelets plasma 90 H20 proteins albumin 60 of plasma proteins nitrogenous wastes nutrients electrolytes respiratory gases pH 735 745 Volume 56Lmales 45Lfemales Functions of Blood 1 Distribution 2 Regulation 3 Protection Erythrocytes RBC anucleate no organelles biconcave no area of cytoplasm is far from surface 97 hemoglobin Hb Hbg Hb made of protein globin and pigment heme group is globular protein contained within cells to prevent loss through vessel walls prevents increased blood viscosity or osmotic pressure Blood Cell Production called quothematopoiesisquot takes place in red bone marrow all formed elements arise from hematopoietic stem cell becomes committed to specialization through unique plasma membrane receptor proteins Red Blood Cell Production called quoterythropoiesisquot stem cell develops into early erythroblast many ribosomes are produced Hb is synthesized and begins to accumulate nucleus is ejected when Hb rises to 34 now cell is called a reticulocyte enters blood and matures as clusters of rer are resorbed Regulation and Requirements of RBC production keeping a constant number is important too few hypoxia deficiency of oxygen too many high viscosity erythropoiesis regulated by kidney cells that respond to hypoxia kidney produces erythropoietin EPO a hormone EPO stimulates red marrow to produce erythrocytes Why a drop in 02 anemia high altitude increased tissue demand RBC last 100120 days removed in spleen Fe cleaved off for storage and reuse bilirubin picked up in liver excreted in feces globulins are metabolized into AAs Leukocytes WBC only formed element with nuclei and organelles immune function fewer than RBC exhibit diapedesis by amoeboid motion approach enflam ed areas by positive chem otaxis 2 major categories 1 Granulocytes neutrophils esinophils basophils 2 Agranulocytes lymphocytes monocytes Production of WBC stimulated by hormones produced from macrophages and Tlymphocytes most granulocytes believed to die after attacking microorganisms Platelets cytoplasmic fragments of megakaryocytes Hem ostasis refers to stoppage of bleeding involves l3 coagulation factors 5 Steps to Coagulation 1 Vascular spasms 2 Plug formation 3 Coagulation Phases of coagulation Phase I pathways to prothrombin activator intrinsic extrinsic Phase II prothrombin catalyzes thrombin Phase III fibrinogen modified to fibrin 4 Clot retraction 5 Fibrinolysis Factors that limit clotting 1 Removal of coagulation factors 2 Inhibition of clotting factors 3 Thrombin absorbed into fibrin strands Blood Groups agglutinogens ABO based on presenceabsence of A or B agglutinogen O is most common for Euros AfAm Asian AB is least common agglutinins STUDY GUIDE FOR HUMAN AampP 2 Third Exam DISCLAIMER This is not a list of the actual questions that will be used on the exam This is simply a tool to help you focus your study time Ifyou successfully answer these questions it does not guarantee that you will make an A on the exam Exam questions will only cover subjects included in this guide 1 What is nonspeci c immunity and what are its components 2 Describe the function of monocytes neutrophils eosinophils basophils and natural killer cells 3 What is the function of in ammation and what are the cardinal signs 4 List the important messengers involved in in ammation and describe their function 5 Explain how phagocytes are mobilized during in ammation 6 What is the role of fever in nonspecific defense 7 Explain how the complement system works 8 Describe the four mechanisms of pathogen destruction 9 How does interferon work 10 What does specific defense mean 11 What are three important aspects of adaptive immunity 12 Compare and contrast humoral and cellmediated immunity 13 What is an antigen 14 Describe haptens 15 What is the major histocompatibility complex 16 Compare and contrast Tcells and B cells 17 What is an antigen presenting cell and what is its function 18 Explain the humoral immune response 19 Explain active humoral immunity 20 Explain passive humoral immunity 21 Describe antibodies and how they work 22 What are the defense mechanisms of antibodies 23 Explain antigen recognition 24 Explain Tcell activation 25 How do cytokines work 26 What is the function of the CD4 cell 27 What is the function of the CD8 cell 28 How does HIV work 29 Explain what happens to people suffering from rheumatoid arthritis type I diabetes mellitus and multiple sclerosis 30 How could the immune system break down 31 What is hypersensitivity How does one become hypersensitive 32 Explain what happens when someone suffers from anaphylactic shock 33 List the four processes involved in respiration 34 Describe the gross and microscopic anatomy of the respiratory system 35 What is the function of the tracheal rings 36 Describe the structural changes observed in the trachea Endocrine System endocrine glands influence metabolic processes using hormones works together with the nervous system are called endocrine because they lack ducts and release hormone directly into blood Endocrine glands pituitary pineal hypothalamus thyroid thymus parathyroid pancreas adrenal gonads hypothalamus is considered a neuroendocrine organ hormone chemical substances secreted by cells into the extracellular fluids that regulate the metabolic function of other cells almost all can be classified as amino acidbased or steroids Paracrine Messengers secreted from a source other than an endocrine gland local hormones that do not typically in uence distant target cells ortravel in blood Eicosanoids One family of paracrine secretions 4 types 1Leukotrines mediate inflammation 2Prostacyclin Inhibits blood clotting and vasoconstriction 3Prostaglandins multiple effects eg raise blood pressure increase uterine contractions local controllers of metabolic activity 4Thromboxanes override prostacyclin to stimulate vasoconstriction and clotting Mechanisms of hormone action hormones increase or decrease rates of normal cellular processes precise response is dictated by target cell hormones typically produce 1 Changes on plasma membrane permeability andor electrical state 2 Synthesis of proteins or certain regulatory molecules 3 Enzyme activation or deactivation 4 Induction of secretory activity 5 Stimulation of mitosis Cell activation amino acidbased hormones cannot enter target cell must use second messengers cyclic AMP cAMP is the best understood second messenger three plasma membrane components determine intracellular levels of cAMP 1 Hormone receptor 2 Signal transducer 3 Effector enzyme Steps 11 ligand hormone binds with receptor the rst messenger G protein dissociates from effector by converting GTP to GDP Pi 2 The G protein travels to activate adenylate cyclase 3 Adenylate cyclase produces cAMP second messenger from ATP 4 7 6 cAMP stimulates a cascade of protein kinase enzyme production within the cell a single kinase enzyme may trigger hundreds of reactions some cells have G proteins that inhibit cAMP production cell reaction to CAMP production depends on specific protein kinases it contains a single cell may have different types of protein kinases that each have a distinct substrate PIPCalcium mechanism Some hormones act through third messengers such as calcium Steps 1 and 2 same as cAMP 3 Activated phospholipase splits PP2 now have diacylglycerol DAG and P3 Both act as second messengers 4 DAG activates specific protein kinases 5 and 6 P3 binds to gated calcium channels or it triggers the release of calcium from the smooth ER 79 Ca in turn become thirdmessengers opens other ion channels functions as a cofactor to activate enzymes binds to calmodulin which in turn activates protein kinases Steroids and Direct Gene Activation steroid hormones are lipid soluble therefore they can easily enter the cell and bind to intracellular receptor this activates receptor so it can bind to speci c protein on the surface of DNA thus speci c genes can be turned on Hormonetarget cell specificity cell must have specific protein receptors to respond to a particular protein Target cell activation is dependent on 1 Blood levels of hormone 2 Relative number ofreceptors 3 Af nity strength of bond between hormone and receptor often target cells will produce more receptors in response to rising blood levels process is called upregulation in other cases prolonged exposure to hormone will desensitize cells process is called downregulation some hormones are rapidly degraded by enzymes in target cells most are removed by enzymes in kidneys and liver Control of hormone release most hormones are regulated by some form of a negativefeedback system 1 Humoral stimuli secretion based on response to changing blood levels of ions and nutrients cells of parathyroid glands monitor Ca levels when too low PTH is released 2 Neural stimuli stimulation of adrenal medulla by sympathetic neurons causes release of norepinephrine and epinephrine 3 Hormonal stimuli anterior pituitary is stimulated to release hormones by the presence of hormones from the hypothalamus hypothalamus pituitary neuroendocrine axis in some cases nervous system can override normal endocrine controls blood sugar levels rise in response to activation of the sympathetic nervous system Major endocrine organs 1 Pituitary gland often called the hypophysis located in sella turcica connects to the hypothalamus by the infundibulum posterior lobe produces oxytocin and antidiuretic hormone both are released directly into the blood from neurons that originate in hypothalamus no direct neural connection between posterior and anterior lobes there is a vascular connection between posterior lobe and anterior lobe Hormones produced by anterior pituitary adenohypophysis 4 hormones are called tropins they regulate the secretory action of other endocrine glands adrenocorticotropic hormone ACTH thyroid stimulating hormone TSH follicle stimulating hormone FSH luteinizing hormone LH 2 hormones are somatotropes somatotropes exert their effects on nonendocrine targets growth hormone GH prolactin PRL all but growth hormone and prolactin act through cAMP secondmessenger systems Functions 1 Adrenocorticotropic hormone ACTH stimulates cells of adrenal cortex helps body to resist stressors 2 Thyroid stimulating hormone TSH stimulates normal development and secretory activity ofthyroid gland thyroid hormones increase metabolic rate 3 Follicle stimulating hormone FSH stimulates gamete production 4 Luteinizing hormone LH jointly with FSH to cause maturation of ovarian follicle stimulates production of testosterone production in males 5 Prolactin stimulate milk production is inhibited in males Posterior pituitary and hypothalamic hormones two hormones are produced in hypothalamus and stored in posterior pituitary 1 Oxytocin strong stimulator of uterine contraction may play a role in sexual arousal of nonlactating females and males 2 Antidiuretic hormone ADH inhibits or prevents urine formation Other endocrine glands Thyroid Thyroid hormone increases metabolic rate Calcitonin lowers blood calcium levels largest pure endocrine gland in the body gland is composed of hollow follicles surrounded by follicle cells between follicles are clusters of cells called parafollicular cells Parathyroid parathyroid hormone PTH raises calcium level in the blood Adrenal su rarenal Corticosteroids from cortex of gland regulate electrolyte concentrations and stimulate glucose production Three types 1 Minleralocorticoids regulate electrolyte concentrations in extracellular fluids particularly potassium and sodium most abundant is aldosterone aldosterone reduces excretion of sodium from the body its primary target are special cells in the kidneys that are stimulated to absorb sodium from the forming urine it also enhances reabsorption from perspiration saliva and gastric juice because water will follow sodium aldosterone plays a role in blood pressure management secretion of aldosterone is stimulated by rising blood levels of potassium low blood levels of sodium decreasing blood volume and pressure 2 Glucocorticoids cortisol is most abundant cortisol release is promoted by ACTH triggered by the hypothalamus cortisol is released in bursts that occur in a patter throughout a 24 hour period levels peak in the morning and are lowest around the beginning of sleep STUDY GUIDE FOR HUMAN AampP 2 First Exam DISCLAIMER This is not a list of the actual questions that will be used on the exam This is simply a tool to help you focus your study time Ifyou successfully answer these questions it does not guarantee that you will make an A on the exam Exam questions will only cover subjects included in this guide and anything from the lecture or book is fair game for an exam 1 Compare and contrast preganglionic and postganglionic neurons of the ANS 2 Compare and contrast the divisions of the ANS 3 Describe the possible pathways that can be taken by the preganglionic neurons of the sympathetic division 4 What are collateral ganglia and what is their function 5 Describe a visceral re ex arc 6 What are neurotransmitters Give examples and explain their function 7 What are cholinergic receptors 8 How are cholinergic receptors classified 9 What are adrenergic receptors and how are they classified 10 Describe the effects of various drugs on the function of the ANS ll Explain how the two divisions of the ANS can work together and give an example 12 Explain the basic function of the endocrine system 13 List the endocrine glands 14 Define a hormone and explain the general function of a hormone 15 What are paracrine messengers 16 What are eicosanoids 17 List the 4 types of eicosanoids and give an explanation of each 18 What do hormones typically produce 19 Explain the cyclic AMP cell activation mechanism 20 Explain the PIPcalcium mechanism 21 How do steroid hormones work 22 Compare and contrast upregulation and downregulation 23 List and explain the three stimuli leading to hormone release 24 Describe the anatomy of the pituitary gland the hormones it produces how it functions 25 Describe the anatomy of the thyroid and parathyroid glands and the hormones they produce 26 Describe the anatomy of the adrenal gland the hormones it produces and how it functions 27 List the hormones the pancreas ovaries and testes produce and what they do 28 What are the components of blood 29 What are the functions of blood 30 Describe the anatomy and function of erythrocytes 31 Describe the structure and function of hemoglobin 32 Explain hematopoiesis 33 Explain erythropoiesis