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FIU / Biology / BIOL 2023 / What is the content of cell theory?

What is the content of cell theory?

What is the content of cell theory?

Description

School: Florida International University
Department: Biology
Course: Human Biology
Professor: Paul sharp
Term: Spring 2016
Tags: Biology, humanbio, and FIU
Cost: 50
Name: Final Exam Study Guide
Description: Covers everything we've seen in class that will be on the final, detailed.
Uploaded: 04/29/2016
58 Pages 31 Views 7 Unlocks
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d_gardier (Rating: )

Part of the notes are distorted and I am unable to read the text.



Exam 1 Study Guide 4/28/16 11:22 PM


What is the content of cell theory?



Living Organisms 

• Basic characteristics of living organisms:

• Organized (has cells, sistems, etc)

• Ability to reproduce

• Have homeostasis

• Respond to stimuli

• Acquire and store energy and materials

• Have an evolutionary history

• Grow and develop

• Homeostasis: body equilibrium, the body’s internal environment remains  constant and between physiological limits.  

• Negative feedback: reduces and eliminates changes in the body, allows  homeostasis. Eg: sweating when hot to get back to normal temperature. • Osmosis: diffusion of water


What is the meaning of negative feedback in organism?



• Tonicity: the osmotic characteristics of a solution across a membrane. • Isotonic: a solution that has the same concentration of water and non diffused solutes on both sides of a membrane.

• Hypertonic: a solution that has high concentration of solutes and low  concentration of water outside the cell.

• Hypotonic: a solution that has a low concentration of solutes and high  concentration of water oustide the cell.  

Cell 

• Smallest unit that has life.  

• There are over 200 different types of cells in the human body

• There are over 50 to 60 trillion cells in the human body.  

• They are so small because they need a large surface area to volume ratio (the  distance between the nucleus and the membrane has to be smaller so that  materials can get to and from the nucleus faster).


What are the parts of the mitochondria?



If you want to learn more check out What is the content of lincoln’s 10% plan?
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• Diffusion: when molecules go from being in a place of high concentration of  them to a place where there is low concentration of them. Also how materials  and nutrients get into the cell. Requires no energy (Passive transport). • Cell theory:

1. Cell: basic unit of life

2. All living things are made of cells

3. New cells only arise from pre-existing cells

• Types of cells:

• Eukaryotes: have membrane bound nucleus and organelles. Eg: animal and  plant cells.

• Prokaryotes: non-membrane bound nucleus and organelles. eg: Bacteria • Parts of the cell:

• Plasma membrane: regulates what enters and leaves the cell, the boundary  between outside and inside the cell. Selectively permeable. Composed of a  phospholipid (has a head that is hydrophillic and a tail that is hydrophobic)  bilayer, sugars and embedded proteins (some allow materials to pass through  them). Named the Fluid Mosaic Model (named for the changing location and  patterns of protein molecules in fluid phospholipid bilayer)

• Facilitated transport: type of passive transport that uss a plasma membrane  carrier (proteins) to carry a substance into or out of a cell, going from a higher  concentration to a lower one.

• Active transport: use of plasma membrane carrier to carry substance from  higher to lower transportation. Requires energy (usually ATP). Eg: sodium potassium pump We also discuss several other topics like Which pr agency was one of the first to have a global presence?

• Metabolism: chemical reactions that happen in the cell

• Enzymes: proteins that speed up chemical reactions by lowering the required  activation energy (the lowest amount of energy needed for it to happen) • Active site: on the surface of an enzyme, it’s where the substrate binds and  the reaction occurs. Specific to each substrate (like a keyhole) • Substrate: reactant in the reaction that is controlled by enzyme. (like the key) • Mitochondria: organelle with 2 membranes  responsible for cellular respiration  (converts glucose into ATP)

• Cellular respiration formula:  

• Parts of the mitochondria:

• Cristae: folded extensions of the inner membrane that produce ATP • Matrix: gel-like fluid inside the inner membrane that contains enzymes  for breaking down glucose found between the cristae. If you want to learn more check out Do campaigns matter?

• Intermembrane space: found between the two membranes • Bomb calorimeter: measures the amount of calories in food • Pathways of cellular respiration:

• Glycolisis:

o Happens in the cytoplasm.

o Doesn’t need oxygen (anaerobic)

o Produces 2 ATP

o Break down of glucose: splits a molecule of glucose C6 into 2  pyruvates of C3  

o Converts 2 molecules of NAD+ (a coenzyme that carries  

hydrogen and 2 electrons) into NADH.

• Citric Acid cycle/Kreb cycle:

o The pyruvates enter the mitochondria’s matrix and are broken  down further and produce 2 ATP per glucose molecule

o Happens in the matrix

o Aerobic process (needs oxygen)

o NAD+ accepts hydrogen and electrons and converts to NADH • Electron transport chain:

o Happens in the inner membrane of the mitochondria

o Electrons pass through membrane-bound carrier molecules from  a higher energy level to a lower energy level.

o Hydrogen is moved to the intermembrane space by active  transport

o Oxygen makes the electrons go from one carrier to the next (like  a parent making their child go down the slide) If you want to learn more check out What is multisystemic theory?
We also discuss several other topics like What happens during menopause?

o When the electrons move, energy is released, and it is used to  pump the hydrogen into the intermembrane space.  

o The hydrogen wants to go back to the matrix because of diffusion  (it’s in a high concentration in the intermembrane space), so it  passes through a protein that spins and produces ATP

o The electrons and hydrogen come from the NADH

o Produces H2O and 32 ATP

• ««Remember: ATP is like a dollar bill, NAD+ is like a giftcard without money,  and NADH is like a giftcard with money for a specific time and place»» • Fermentation: anaerobic process. Allows the NADH to release its electrons  and its hydrogen to pyruvate. Converts pyruvate to lactate to do this.  Produces 2 ATP per glucose. Yeast produces alcohol and C02 • Endocytosis: a portion of the plasma membrane invaginates to envelop a  substance or fluid. Types:

• Phagocytosis: solid particles

• Pinocytosis: fluids

• Receptor-mediated: uses membrane protein receptor to concentrate  specific molecules.

• Exocytosis: vesicles in cell fuse with the plasma membrane during secretion  (reverse of endocytosis) Eg: Neurotransmitters, hormones.

• Cytoplasm: cytosol and organelles

• Cytoskeleton: mantains cell shapes, anchors organelles and allows cell  movement. Composed of:

• Microtubules: long hollow protein cylinders found in the cytoplasm and  in cilia and flagellas, used as tracks for organelle movement.

• Intermediate filaments: protein fibers that provide strength and support • Microfilaments: actin protein fibers that move cell and organelles (like  little motors)

• Centriole: short cylinders of microtubules that divide and organize spindle  fibers during mitosis and meiosis

• Centrosome: 2 centrioles that function as a microtubule organizing center.  Active during cell division.

• Nucleus: houses chromosomal DNA

• Nuclear envelope: double membrane that encloses nucleus with nuclear  pores

• Chromatin: diffuse threads containing DNA (DNA not in form of  chromosomes)

• Nucleolus: region that produces subunits of ribosomes.

• Nucleoplasm: semifluid medium inside nucleus

• Nuclear pores: allow ribosomal subunits to exit and proteins to enter. • Ribosomes: synthesize proteins using mRNA (messenger RNA: a copy of  DNA that has genetic information) template

• Endomembrane system: a series of membraneous organelles that process  materials for the cell:

• Nuclear envelope

• E.R. (endoplasmatic reticulum): continuous of the nuclear envelope, has  saccules and channels:

• Rough E.R.: has ribosomes embedded on the side that faces the  cytoplasm. The ribosomes synthesize proteins and then the proteins  enter the ER interior for processing and modifications

• Smooth E.R.: has no ribosomes. Synthesizes phospholipids. • Golgi apparatus: modifies lipids and proteins from the ER and sorts,  packages and distributes molecules synthesized by cell (like the Fedex  of the cell)

• Lysosomes: membraneous sacs produced by the Golgi, contain  hydrolitic enzymes that break down things inside them. Can fuse with  endocytic vesicles.

• Vesicles: tiny membraneous sacs

• Meiosis: cell division in sperm and ovules (only in sexual reproduction).  Daughter cells receive haploid number of chromosomes in varied  combinations.

• Mitosis: cell division for growth, development and repair. Daughter cells  receive exact chromosomal and genetic info that parent cell has.  • Cell cycle: repeating sequence of cellular events

•  

• 1. Interphase: has 3 stages:

• a. Growth (G1): cell returns to normal phase, resumes its functions and  doubles its organelles

• b. Synthesis (S): DNA replication (now a chromosome has 2 sister  cromatids)

•  

• c. Growth (G2): increase in growth and final preparations for division • 2. Mitosis

• 3. Cytokinesis: division of cytoplasm

MITOSIS AND DNA REPLICATION 

• DNA (deoxyribonucleic acid): composed of two complimentary strands of  nitrogenous bases (Thymine (T), Cytosine (C), Adenine (A) and Guanine (G)).  Never leaves the nucleus. Has a sugar-phosphate backbone (sugar is  deoxyribose) and the nitrogenous bases are like the rungs of a ladder.  (always T+A, G+C)

• Centromere: part of the chromosome where the sister  

chromatids attach, also where the mitotic spindle  

attatches to separate them.

• Mitotic spindle: formed by centrosomes where  

microtubules move chromosomes

• DNA replication: happens during S phase of the interphase. The original  strand of DNA is ‘unzipped’ by enzymes and each strand is completed by a  new strand with the complimentary bases of each part. (Green= old strand,  yellow= new strand)

• Chareotype: shows the 23 pairs of homologous chromosomes laid out.  (similar in size and colour, the pair has the same genes for hair, etc, but not  the same sequence because one comes from the mother and the other from  the father)  

• Mitosis: daughter cells are identical to father cells

• Prophase: centrosomes form and shoot microtubules (formation of the  mitotic spindle starts) and the nuclear envelope breaks down.

• Metaphase: chromosomes align in the middle of the cell and the mitotic  spindle is fully formed

• Anaphase: sister chromatids are separated and pulled to opposite sides of the cell

• Telophase: mitotic spindle breaks down, nuclear envelope rebuilds • Cytokinesis: cleavage furrow allows cytoplasm to divide.

• Cancer: mutations. Sometimes during replication, enzymes make mistakes. A  cancer cell cannot communicate with other cells so they continue to grow  even when it is no longer needed.

• Checkpoints: if a mistake during replication happened, these checkpoints  ensure that it’s taken care of. (sometimes it also fails)

• G1 and G2: apoptosis (cell death) will happen if DNA is damaged and  can’t be repaired

• M: mitosis doesn’t occur if cells aren’t aligned correctly.

• Diploid: 46 chromosomes in humans, “2n”

• Haploid: 23 chromosomes in humans, “n”

MEIOSIS: 

• Only sex cells (sperm and eggs)

• Goal: produce haploid cell

• Meiosis 1: reductional division (homologous pairs  

separate), 1 cell produces 2 haploid cells

• Prophase 1: chromosomes have duplicated, mitotic spindle starts,  nuclear envelope starts to break down. Crossing over: homologous  pairs synapse (‘get freaky’), where they cross or join, they exchange  material, that place is called the chiasmata. Crossing over increases  genetic variability.

• Metaphase 1: homologous pairs align in the middle of the cell.  Independent assortment: random orientation of the homologous pairs. • Anaphase 1: whole cromosom is pulled apart (the pairs are separated) • Telophase 1: interkinesis (type of cytokinesis) occurs. Same as mitotics  telophase

• Meiosis 2: sister cromatids separate, produces 4 haploid cells • Prophase 2: no crossing over (this only happens in prophase 1, meiosis  1). The nuclear envelope breaks and the spindle begins to form • Metaphase 2: the chromosome aligns in the middle

• Anaphase 2: sister cromatids are separated

• Telophase 2: same as mitotis telophase, interkinesis also takes place.

⇦MEIOSIS I⇦MEIOSIS II

 

• Spermatogenesis: production of  

sperm. Starts off with one sperm that produces 4 viable sperm cells. Starts in  puberty.

 <--- Oogenesis

• Oogenesis: production of eggs. 1 viable egg is produced. Starts since the  baby girl is in the womb. The secondary oocyte will only go through meiosis 2  if it has been fertilized by a sperm.

• Polar body: has the same genes as the oocyte

GENETICS 

• Gene: DNA sequence found in chromosomes

• Allele: version of a gene (for the gene of hair color, there are alleles for dark  hair, blond, red, etc)

• Locus: site where the gene is on the chromosome

• Genotype: genetic information responsible for a specific trait (written as Aa,  BB, cc)

• Phenotype: the physical expression of a gene (blue eyes,  

⇦ Legend

long fingers)

• The capital letter (A) means that the gene is dominant (masks  the other gene), while a lowercase letter (a) means that the gene is recessive  (will only express itself in the phenotype if the other gene is also recessive

aa)

⇦Punnet square

• Heterozygote: two different alleles for a gene (Aa)

• Homozygote: two of the same alleles for a gene (AA, aa)

• Punnet square: the female always goes on top, the male goes downwards.

• Phenotypic ratio: proportion of dominant:recessive. eg: the ratio for the punnet  square above would be 3:1.

• Dominant always masks the recessive in a heterozygote

• Principle of segregation: 2 alleles of a gene segregate during gamete  formation and are rejoined at random during fertilization. (like independent  assortment)

• Remember: heterozygote is a capital letter and a lowercase letter (Aa) • Incomplete dominance: happens when the heterozygote is intermediate  between the 2 homozygotes. Eg: you have HH= straight hair, hh= curly hair  but Hh= wavy hair. If the parents are HH and hh, all of the children will be Hh  and therefore have wavy hair.

• Codominance: happens when alleles are equally expressed in the  heterozygote (one doesnt mask the other) (eg: blood type)

• Multiple-allele inheritance: inheritance pattern in which there are more than 2  alleles for a particular trait. eg: blood type, because A, B, O

• Polygenic inheritance: inheritance pattern in which more than 1 gene affects a  trait. eg: skin tone, height--3 genes involved in these: A,B,C

• Autosomes: any chromosomes other than the sex chromosomes • Sex chromosomes: determine the sex of an individual (XX-female,XY-male) • Sex-linked: refers to an allele that occurs on the sex chromosome but may  

control a trait that has nothing to do with the sex characteristics of an  individual.

• X-linked: refers to an allele located on the X chromosome.

• eg: XB- normal vision, Xb=red/green colorblind  

• Pedigree: a graphical representation of matings of offspring over multiple  generations for a particular trait (like a family tree that  

indicates the family members' genotype and phenotype).  

• How to do pedigree problems: look at each trait and do a  

punnet square to find the parents' possible genotype.

4/28/16 11:22 PM

Nervous System 

• Organ system consisting of the brain, spinal cord, and associated nerves that  coordinates the other organ systems of the body

• Central nervous system:

• Brain and spinal cord

• Peripheral nervous system:

• Nerves: composed of axons and dendrites

• Divides into:

• Somatic nervous system: nerves that serve the skin, skeletal muscle and  tendons, voluntary and involuntary control (reflexes)

• Autonomic nervous system: regulates the activity of cardiac of smooth  muscles (many associated with gastrointestinal tract and blood vessels that  control blood flow to the body), organs and glands, also involuntary control  (remember: autonomic=automatic things--no control over heart beating etc).  Divides into:

o Sympathetic: activities associated with emergency (fight or flight) AKA:  E division (think of Emergency)

o Parasympathetic: active under normal conditions (rest and digestion)  AKA: D division (think of Diaresis--production of urine)

• Functions:

1. Receives sensory input: senses (touch, hearing, smell, etc) eg: the smell of baking  cookies is picked up by the PNS and that info is sent to the CNS

2. CNS performs information processing and integration: the CNS reviews info and  stores it as memories. eg: the smell of baking cookies evokes pleasant memories of  their taste

3. CNS generates an appropriate motor response: eg the smell of baking cookies  makes the CNS actives the PNS to activate muscles, glands, organs (move to eat  the cookies)

• Nervous tissue contains 2 types of cells:

• Neurons: nerve cells that transmit impulses between parts of the nervous  system:

o Nerve signal: action potentials traveling along a neuron, conveys info o Action potential: change in electrical conditions at a neurons  

membrane (like a line of dominoes, one falls and then each one keeps  falling after that). Normal state: negative on the inside, positive on the

outside: Neuron communication happens through nerve signals and  action potential. The inside of the axon is negative and the outside is  positive when it's at rest, but when a nerve signal is happening it flips  the charges of the inside and the outside.

o Refractory period: portion of axon immediately following the action  potential is unable to conduct and action potential that ensures a one way direction of a signal (cell body to axon)  

o Parts:

▪ Cell body,  

▪ Dendrites  

▪ Axon

o Types:  

▪ Sensory neurons: sensory receptors in the PNS that take the  

info to the CNS

▪ Interneurons: found entirely in the CNS (work as a relay)  

▪ Motor neurons: move the info from the CNS to the PNS so that  the body moves

• Neuroglia: nonconducting nerve cells that support the neurons

o Schwann cells: found connected to the axons, nucleus can be seen,  like insulation for the cells, conducts saltatory conduction (jumping: the  info jumps between cells which is faster--100 times faster)  

• Afferent: going to the spinal cord (the info of the mallot hitting the knee is going to be  processed)

• Efferent: away from spinal cord (the info goes to the muscle to make it move) • Na+: sodium, starts an action potential when is rushes inside the plasma membrane  causes the flip of the signs

• Membrane potential: difference in electrical change between 2 sides of a membrane. • Resting membrane potential: polarized plasma membrane (-70 mV--you are -70  negative inside compared to the outside), the net number of positively charged ions  outside and the negatively charged ions inside it

• Sodium-potassium pump: membrane protein that uses ATP to pump 3 Na+ out and  2 K+ into the cell, there's always going to be a negative charge on the inside of the  membrane this way. This sets things up for diffusion, because the Na+ will be in high  concentration outside and will want to go inside and vice versa with the K+, when  this happens, the action potential is happening.

• Orange= sodium channel, pink=potassium channel

• Potassium can sometimes leak out, this makes the inside even more negative. • What happens during action potential?

1. Conductance of a nerve signal in axons

2. All or nothing event (either works or doesn't work), self propagating 3. 1st sodium gates open resulting in depolarization (the first domino has fallen  down) (once the gate opens, the sodium rushes inside the membrane  because of diffusion, so the inside of the membrane will no longer be  negative)

4. Next potassium gates open resulting in repolarization (lifting the domino back  up) (the potassium rushes outside because of diffusion)

5. Sodium-potassium pump restores original ionic distribution

• Stimulus: activates neuron and begins action potential (causes first domino to fall) if  threshold is met (-40 Mv, when the voltage changes from -70 to -40, then the sodium  gate opens up), eg: pricked by a pin

• Protein channels (gates):  

1. Voltage gated: opens and closes in response to voltage changes across  membrane

2. Ligand gated: opens and closes when a specific chemical binds to it 3. Mechanically regulated: responds to physical distortions of the membrane  surface

• Synapse:  

• The junction between neurons (empty space between axon  

terminal/presynaptic membrane and cell body or dendrites/postsynaptic  membrane); nerve signal can not jump synaptic cleft

• 1st: presynaptic membrane (axon terminal)

• 2nd: synaptic cleft

• 3rd: postsynaptic membrane (usually dendrite)

• Neurotransmitters: chemicals responsible for transmission across a synapse. Closer  ti -40mV you will communicate, if its getting further from the -40mV, then no. The  neurotransmitters get out through exocytosis. Stored in synaptic vesicles at axon  terminal. Also transmits signal between:  

• Nerve--- muscle

• Nerve--- organ

• Nerve--- gland

• Events at synapse:

1. Nerve signal travels along axon to an axon terminal

2. Ca2+ ion gates open and Ca2+ rushes in axon terminal

3. Ca2+ ions promote fusion of synaptic vesicles with presynaptic membrane 4. Exocytosis of neurotransmitter into synaptic cleft and diffusion occurs 5. Neurotransmitters attach to receptors on the postsynaptic membrane. Only  single type of channel opens

6. Excitatory or Inhibitory synapse, depending on the neurotransmitter 7. Integration: summing up of excitatory and inhibitory signals

8. Termination of neurotransmitter effects: degraded by enzymes

9. Reuptake by presynaptic membrane

10.Diffusion out of synapse

• Neurotoxins: include numerous chemicals that poison the nerve. Ex. Novocain • Central Nervous System: where sensory information is received & motor control is  initiated

• Meninges: protective membranes that cover brain and spinal cord. Eg. Meningitis infection of the meninges

• Cerebrospinal fluid: cushions and protects CNS; fills spaces between meninges.  Helps maintain blood-brain barrier

• Ventricles: interconnecting chambers that produce and serve as a reservoir for  cerebrospinal fluid.

1. Lateral ventricles: proximate to cerebrum

2. Third ventricle: proximate to diencephalon

3. Fourth ventricle: proximate to cerebellum (extends all the way down to the  spinal cord)

• Grey matter: contains cell bodies and short, nonmyelinated fibers • White matter: contains neuron fibers that run together in bundles called tracts (the  myelinated axons make it look white):

• Ascending tracts take info to the brain

• Descending tracts take info away from the brain

• Tracts cross paths just after they enter and exit the brain

• (spinal cord diagram)

• Spinal cord: extends from base of brain and proceeds inferiorly in the vertebral  column, allow for communication between brain and peripheral nerves, center for  thousands of reflex arcs. Has grey matter on the inside and it looks like a butterfly,  white matter on the outside (opposite to brain--brain has white inside and grey  outside).  

• The bulb structure (dorsal root) is where the sensory information goes to brain  and is ascending

• The ventral root is of motor neurons that is descending

• Brain: enlarged superior portion of the CNS located in cranial cavity of the skull • Cerebrum: largest part of brain, consists of 2 cerebral hemispheres (left and  right). communicates with and coordinates the activities of the other parts of  the brain

o Left hemisphere: has greater control over language and mathematical  abilities, logic, analysis

o Right hemisphere: more visual-spatial skills, intuition, emotion and art  and music

• Sulci: grooves that divide each hemisphere into lobes:

o Frontal lobe: motor functions, permits voluntary muscle control,  enables one to think, problem solve, speak and smell 

o Parietal lobe: receives info from sensory receptors in skin and taste receptors in mouth

o Occipital lobe: interprets visual input and combines it with other  sensory experiences

o Temporal lobe: sensory areas for hearing and smell

• Cerebral cortex: outer layer of cerebral hemisphere, composed of grey matter,  receives sensory info and controls motor activity. Accounts for sensation,  voluntary movement and thought processes. Very thin layer (2-4mm) but  makes up 40% of the biomass of the brain and has over 1 billion cell bodies.  Enables us to perceive, communicate, remember, understand, appreciate and  initiate voluntary movements (associated with consciousness).

o Higher mental functions: memory (ability to hold a thought in mind or  recall events from the past) and learning (retain information)

• Diencephalon: part of the forebrain between the 2 hemispheres and midbrain.  has the thalamus, 3rd ventricle and hypothalamus

• Thalamus: "gatekeeper to the cerebrum" by controlling which received  sensory info are passed on to the cerebrum (filters noises you don't pick up  for example)

• Hypothalamus: helps maintain homeostasis: regulates hunger, sleep, thirst,  body temp, heart rate, etc and forms floor of 3rd ventricle.

• Corpus callosum: extensive bridge of nerve tracts, enables communication  between left and right hemispheres

• Cerebellum: coordinates equilibrium and motor activity to produce smooth  movement (looks like a tree)

• Hypothalamus: endocrine system (hormone secretion)

• Brain stem: contains midbrain pons and medulla oblongata

• Midbrain: bellow thalamus and above pons. Reflex centers for the eye  muscles and tracts (closing eye/flinching/blinking)

• Pons: bellow midbrain and above medulla oblongata. Assist the medulla  oblongata in regulating breathing rate. Respiratory reflexes: apneumatic (stop  breathing while sleeping/doesn't allow you to hold your breath very long--cant  die) and pneumotaxic (allows for normal shallow breathing). Provides linkage  between upper and lower levels of the CNS.

• Medulla oblongata: posteriorest part of the brain stem. Where tracts (from  Right to left) cross. Regulates heartbeat blood pressure and breathing. Reflex  centers: sneezing coughing hiccupping and swallowing

• Senses:

• General sense: touch

• General sensory receptors:

1. Mechanoreceptors: touch pressure vibration and strech

2. Thermoreceptors: temp changes (located in hypothalamus and skin)

3. Nociceptors: pain: respond to damaging stimuli

• Skin: composed of epidermis (outermost layer), dermis (thick, has cutaneous  receptors)

• Special senses: hearing vision taste smell and balance

• Sensory receptor: dendritic end organs or parts of other cell types specialized to  respond to a stimulus

• Sensation: conscious perception of a stimuli

• Sensory adaptation: when we stop taking into account a sense after its been  consistent after a long period of time (why we cant smell our perfume after a while  even though its there)

• Chemoreceptors: respond to chemical substances (are plasma membrane receptors  that bind to specific molecules) (olfatory and taste cells)

• Taste buds: sense organ containing receptors for taste. Approx 10000 in adults most  in tongue. Includes supporting cells and taste cells that end with microvilli. When  molecules bind to receptor proteins of microvilli, nerve signals are generated. 4  primary types of taste (saliva is needed to taste)

• Olfactory cells: located within olfactory epithelia high in the roof of the nasal cavity.10  to 20 million in adult humans. Modified neurons, each with tuft of 6 to 12 olfactory  cilia. Each olfactory cell has only 1 type of several hundred possible receptor  proteins

• Types of Sensory Receptors Associated with Sight:

• Photoreceptors: sensory receptor in the retina that responds to light stimuli.  o Rod cells: dim-light and peripheral vision receptors; more numerous.  Ubiquitous throughout the entire retina except the fovea centralis (no  color vision). When rod absorbs light, rhodopsin splits into opsin and  

retinal. A cascade of reactions results in ion channels closing in rod  plasma membrane.

o Cone cells: operate in bright light and provide high-acuity color vision.  Located primarily in the fovea centralis. Slight differences in protein  opsin structure account for three different types of cones: B (blue), G  (green), R (red)

• Parts of the eye:  

• Retina: innermost layer of the eyeball that contains rod and cone cells • Fovea centralis: small pit where cones are densely packed (light is normally  focused on the fovea)

• Optic nerve: sensory fibers from the retina that take nerve signals to the visual  cortex

• Lens: capable of changing shape too focus on things in a far distance or in a  small distance. When one gets older older, it starts getting more difficult for it  to change shape.

• Rhodopsin: complex molecule made up of the protein opsin and the light  absorbing molecule retinal

• Types of Sensory Receptors Associated with Hearing:

• Mechanoreceptors: stimulated by mechanical forces when they or adjacent  tissue are deformed by touch, pressure, vibrations, and stretch. Cells that are  going to respond to mechanical stimuli

• Hair cells: cell with stereocilia (long microvilli) that is sensitive to mechanical  stimulation

• Mechanoreceptors for hearing and equilibrium are located in the inner ear • The Ear:

• Outer ear: functions in hearing; filled with air. The sound waves pass through  here

o Pinna: the external ear flap that catches sound waves

o Auditory canal: directs sound waves to the tympanic membrane. Not  the same as the auditory tube → auditory tube is much smaller than  the auditory canal.  

o Fine hairs and modified sweat glands that secrete earwax (cerumen) • Middle ear: functions in hearing; filled with air.  

o Tympanic membrane (eardrum): vibrates to carry the wave to three  small bones (ossicles)

o Ossicles: amplify sound waves x20 → smallest bones in the body. ▪ Malleus  

▪ Incus  

▪ Stapes: called this because it looks like the stirrup (the thing that  you put your feet on to ride a horse). It kicks on the oval window  

each time it vibrates (after oval window there's the liquid of the  

cochlea)

o Eustachian tube (auditory tube): equalizes pressure so the eardrum  doesn't burst. Connects throat to the middle ear

• Inner ear: functions in hearing and balance; filled with fluid. Important for both  hearing and balance

o Cochlea: converts vibrations into nerve impulses

▪ Organ of Corti: spiral organ (looks like a snail), contains hairs  

that bend with vibrations or waves, this sends impulses to the  

cochlear nerve that sends them to the brain. Pitch is determined  

by varying wave frequencies detected by different parts of this  

organ. Volume is determined by the amplitude of the wave.

o Semicircular canals: rational equilibrium, 3 canals

▪ Detects angular movement (rotational equilibrium)

▪ Depends on hair cells at the base of each canal (ampulla), they  are embedded in cupula

o Vestibule: gravitational equilibrium,  

▪ Utricule: hair cells that have a jelly-like membrane on top, it  

swings the opposite direction of the movement. You know which  

way you're going (horizontally) even if you have your eyes  

closed. In a horizontal plane

▪ Saccule: in a vertical plane, helps to know if you're going up or  

down, the jelly-like membrane on top of hair cells swings the  

opposite direction of the movement.

• Auditory tube: equalizes pressure in the ear, connects the middle ear to the back of  the throat

• How we hear:

1. Pinna catches sound waves

2. Auditory canal directs sound waves to tympanic membrane

3. Tympanic membrane vibrates and wave is carried to ossicles (little bones) 4. Stapes vibrates and strikes the membrane of the oval window

5. Vibration of oval window causes fluid waves within the cochlea

6. Pressure waves move from vestibular canal to tympanic canal crossing  basilar membrane

7. Basilar membrane moves up and down, stereocilia of hair cells embedded  intectorial membrane bend

8. Nerve signal begins in the cochlear nerve and travels to the brain • Round window: relieves pressure  

Blood: 

• It's a type of connective tissue in which cells are separated by plasma

• Plasma: liquid portion (90% is water) of blood ( makes up 55% of blood)that includes  nutrients, waste, salts, and proteins. Types of plasma proteins:

1. Albumins: contribute to the plasma's osmotic pressure (water pressure, like  little sponges that absorb the water so that it doesn't leak out of veins), found  in egg whites

2. Globulins: antibodies, hemoglobin (provide oxygen), etc (like an archer's  arrows that are made of globulin, that attack any virus or pathogen) 3. Fibrinogen: forms blood clots when activated, blood clots are important so  that when we cut ourselves we don't keep on bleeding forever.  

• Test question: which proteins are associated with blood?

• Formed element: includes red and white blood cells and platelets, make up 45% of  blood

• Platelet: aka thrombocyte, cell fragments of Megakaryocyte, involved in clotting • Functions of blood:

• Primary transport medium: carries oxygen, CO2, hormones, nutrients, etc 1. Defends against pathogens and helps seal damaged blood vessels:  antibodies, phagocytes and platelets do this

2. Regulatory functions: regulates temperature, osmotic pressure, buffers to  stabilize the pH 7.4

3. Red blood cells: aka RBC, erythrocyte. Contains the protein hemoglobin.  Produced in red bone marrow. It looks like a pizza dough because it has a  larger surface area this way

• Hemoglobin: has iron and carries oxygen. Each one contains 4 heme groups (little  proteins) and each heme group can transport 1 oxygen molecule, so one  hemoglobin protein carries 4 oxygen molecules. Approx. 280 million hemoglobin  molecules in one red blood cell. Carbon monoxide binds more strongly to the heme  than oxygen, this is bad because it leads to us not being able to breathe in situations  like being in a garage with car running and door closed.

• Anemia: insufficiency in the oxygen carrying ability of blood, due to shortage of  hemoglobin. Females are more likely to be anemic because of the loss of blood they  experience every month in their period

• If you go to a higher place like a mountain where there's less oxygen, there's gonna  be a low level of oxygen in the blood so the kidney will produce a hormone called  erythropoietin that will cause stem cells to increase red blood cell production in red  bone marrow so that the blood's oxygen level returns to normal (see picture below) • Clotting: process of blood coagulation, usually initiated when injury occurs

1. Blood vessel is punctured

2. Platelets congregate and form a plug

3. Platelets and damaged tissue cells release prothrombin (like scissors, super  sharp) activator (this activator will "remove the safety lock on the scissors,  and turn prothrombin intro thrombin) which initiates a cascade of enzymatic  reactions

4. Fibrin threads form and trap red blood cells

• Blood transfusions: whole blood of just a component of blood (red blood cells, etc),  introduced into the bloodstream

• Agglutination: clumping of red blood cells due to reaction of antigens on red blood  cell surface and antibody in the plasma. Happens when two blood types that aren't  supposed to mix, mix during a transfusion, causes the blood to become more solid  instead of a liquid form.  

• ABO blood typing: based on the presence or absence of 2 possible antigens (Type A  antigen or type B antigen). Depending on the blood type, the rbc produces different  antibodies.

• Type A: red blood cells have type A surface antigens. Plasma has anti-B antibodies  that look like Y

• Type B: rbc have type B surface antigens, plasma has anti-A antibodies that look  like a moon.

• Type AB: rbc have both type A and type B surface antigens, and the plasma does  not have type A or type B antibodies.

• Type O: rbc have neither type A or type B surface antigens, plasma has both anti-A  and anti-B antigens.

• Test question: what blood types can safely donate blood to a type O? Only a person  with type O, because type O has antibodies against type A and type B. •

• When your antibodies attack your own rbc, then you have an autoimmune disease. • Rh blood groups: based on the presence of Rh factor (antigen) on rbc • Rh-: has antibodies against Rh+

• Rh+: 85% of Americans are this type

• Hemolytic disease of newborn (HDN): happens in a newborn when the mother is Rh and the father is Rh+. In a normal pregnancy no blood is mixed between mother and  baby, but when the baby is coming out, things can get messy and blood can mix. So  if the baby is Rh+, the blood from the mother containing Rh- will have antigens that  

attack the baby's rbc.  

• RhoGAM is an antibody that is administered around 7 months into the pregnancy,  contains small amount of antibodies that attack the baby's rbc if they leak into the  mother's blood, quickly so that the mother doesn't produce many antibodies that  attack the baby, so both the baby and the mother are safe.

Cardiovascular system: 

• Organ system in which blood vessels distribute blood by the pumping action of the  heart.

• Parts:

• Heart: muscular organ located in the thoracic cavity. Rhythmic contractions  maintain blood circulation

• Blood vessels: closed delivery system that begins and ends at the heart. • Functions:

1. Contraction of the heart generates blood pressure (moves blood)

2. Blood vessels transport blood from heart to arteries (big transport vessels,  like the turnpike or the i-95), capillaries (where all the action takes place) and  veins (to go back to the heart)

3. Gas exchange occurs at the capillaries (CO2 is picked up and O2 is dropped  off--because the cells need the O2 for cellular respiration). Nutrients are  delivered to the cells by blood, while the blood picks up their waste.

4. Heart and blood vessels regulate blood flow, according to the body's needs • It has to send blood to the kidneys for the blood to be cleansed, to the digestive  system to pick up the nutrients from the food we ate, to the respiratory system to  pick up the oxygen (because after taking oxygen to the cells, the blood leaves  without oxygen and needs more)

• Types of blood vessels:

1. Arteries: they conduct blood away from the heart, they carry oxygenated  blood (has one exception)

2. Capillaries: smallest of the blood vessels (it has to be small so that diffusion  can take place), takes oxygen to the cells and exchanges it with CO2, "where  all the action happens"

3. Veins: they return blood towards the heart. Always have deoxygenated blood  (has only 1 exception)

(the little dots in the purple parts are nucleuses) • Capillaries: found between veins and arteries, very small and diffusion happens very  easily and quickly in them

• Smallest blood vessels

• In some cases, only one endothelial cell forms the entire circumference (they  are just 1 cell thick)

• They provide for exchange of materials like gases, nutrients, etc by diffusion. • Arterial system: the arteries near the heart withstand and smooth out large pressure  fluctuations, they expand and recoil as the heart beats to propel blood onward • Pulmonary Artery: exception to the rule, it carries deoxygenated blood (takes it to the  lungs)

• Pulmonary vein: only vein that is oxygenated in the body

• Arterioles: small arteries,

• When the muscle fibers contract, the vessel constrict; when the muscle fibers  relaxes, the vessel dilates.

• Constriction or dilation controls blood pressure

• They lead into the capillary bed

• Capillary bed: interweaving network of capillaries

• Pre-capillary sphincter: controls blood flow through a capillary bed (sends it through  something like a shortcut). It's regulated by vasomotor nerve fibers and local  chemical conditions.

• Arteriovenuous shunt: enables blood to pass directly from an arteriole to a venule  (the shortcut mentioned above)

• Veins: same 3 layers as arteries, but less smooth muscle and connective tissue,  they have thinner walls and they have valves

• Venous valves: they resemble semilunar valves in heart in structure and function, so  what they do is prevent blood to go backwards. They are most abundant in veins of  the limbs. They depend on our movement, if we cross our legs we smush some  veins and the blood is forced to go back to the heart.

• Varicose veins: veins that have become dilated because of damaged valves.  They can be influenced by: heredity, obesity, prolonged standing, pregnancy  (they go away after pregnancy). Eg: hemorrhoids, they are varicose veins in  the anus.  

• Venules: small veins that drain blood from the capillaries.

• Heart: muscular organ located in the thoracic cavity. Like a double pump. Its  rhythmic contractions maintain blood circulation. Left side is systemic (body), right is  to the lungs, that blood doesn't mix. Has 4 chambers (left and right atriums and  ventricles). Authorhythmicity: it beats on its own and never gets a rest.

• Myocardium: composed of cardiac muscle formed by muscle fibers tightly  joined together by intercalated disks (like puzzle pieces):

o Gap junctions: aid in simultaneous contractions of cardiac fibers o Desmosomes: protein fibers that prevent overstretching of the heart • Pericardium: protective membrane that surrounds the heart and secretes  pericardial fluid (a lubrication fluid that allows the heart to move freely without  friction)

• Septum: wall that separates the right and left sides of the heart, so that  oxygen poor blood and oxygen rich blood never mix

• Atrium: superior chambers (left and right) that receive blood

• Ventricles: inferior chambers (left and right)

• Atrioventricular valves (AV): located between the atrium and the ventricles  and prevent backflow of blood into the atria when ventricles are contracting: o Tricuspid: right side of the heart

o Bicuspid: aka Mitral valve, left side

• Semilunar valves: prevent blood return into the ventricles after contraction • Heart strings (chordae tendineae): prevent the flaps of the valves from  overextending, like a tight seal, prevent valves from inverting.

• Sound of the heart is called "Lub-Dub": Lub is the AV valves slamming shut, the Dub  is when the semilunar valves slam shut.

• Heart murmur: a leaky AV valve, a sight swishing sound after the "Lub" • Systemic circuit: blood vessels transport oxygenated blood from left ventricle to  body, deoxygenated blood returns to right atrium

• Pulmonary circuit: blood vessels that take deoxygenated blood from right vent to  lungs, oxygen blood returns to left atrium

• Coronary artery: supplies blood oxygen and food to the wall of the heart (septum). If  a person eats a lot of fatty foods, plaque accumulates and creates a blocked  coronary artery results in a myocardial infarction. To solve this, surgeons create a  bypass surgery.

• Cardiac cycle: one heart beat, composed of two parts:

• Systole: contraction  

• Diastole: relaxation  

• When doctors take blood pressure, they look for the first beat and the last beat after  the thing around the arm is loosened and the blood starts going to the arm again.  The result will show (for example): 120/80 pressure, 120 is systole and the 80 is  diastole.

• Diastole is more stable, it doesn't change if we are anxious or not. • Normal blood pressure reading: below 120/below80

• Cardiac conduction system:

• SA (sinoatrial) node:  

o Specialized myocardial cells in the wall of the right atrium

o Like the pacemaker of the heart, 70 beats per minute

o Initiates the heartbeat, sends the information to the heart

o If this node is damaged, you will only have 50 beats per min

• AV (atrioventricular) node: specialized mass of conducting cells located at the  atrioventricular junction in the heart. If this node is damaged, you will only  have 30 beats per min

• There's a space between the two nodes so that there's time between  electrical impulses. So that the atria contract before the ventricles.

• Nodes create the information that makes the parts of the heart contract, like  the brain sends signals to the body for it to move via neurons, the nodes are  like the brain and send the signals through the atrioventricular bundle and the  Purkinje fibers.

• Atrioventricular bundle: bundle of specialized fibers that conduct impulses  from the AV node to the right and left ventricles. (they carry the information  that the nodes send: it tells them to contract or not)

• Purkinje fibers: modified cardiac muscle fibers of the cardiac conduction  system

• ECG (Electrocardiogram): recording of electrical activity associated with the  heartbeat.

• P wave: atria about to contract

• QRS wave: ventricles about to contract

• T wave: ventricular muscle fiber recovery

• Ventricular fibrillation: the heart is not pumping properly.

• When this happens, the person needs to be defibrillated using the 2 shock things  that are put on people's chest in movies, and the doctors say "clear". What this does  is apply a strong electrical current for short time so that all heart cells discharge  electricity at once.

4/28/16 11:22 PM

Digestive System: 

• Gastrointestinal tract: a continuous hollow tube extending from the mouth to the  anus. AKA: alimentary tract

• It's made up of the:

• Oral cavity: the mouth

o Hard palate: bony anterior part of the roof of the mouth

o Soft palate: only muscular portion at the back roof of the mouth

o Uvula: tissue tag hanging from the soft palate

o Salivary glands: glands associated with the mouth, they secrete saliva.  Saliva isn't secreted under the tongue

o Saliva: solution of water, mucus, salivary amylase, lysozyme, and  bicarbonate. (salivary amylase is the first enzyme that begins the  

digestion of starch--carbs)

o Tongue: occupies the floor of the mouth. Has 4 functions:

1. Grips food

2. Repositions food between teeth

3. Mixes food with saliva (because the saliva has salivary  

amylase- an enzyme that starts to break down the  

carbohydrates in food we eat)

4. Movements form the bolus (the mush of the food we are  

chewing that goes down when we swallow)

o Teeth:

▪ Lie in sockets in the gum covered margins of the maxilla and  

mandible

▪ 2 main divisions: crown and root

▪ 32 teeth in adults

▪ Composed of:

???? Enamel: hard material composed of calcium compounds  

that cover the crown (the part of the tooth that is above  

the gum)

???? Dentin: thick layer of bone-like material beneath enamel

???? Pulp: inner tissue containing blood vessels and nerves

▪ Problems:

▪ Dental caries (cavity): hole in the tooth that results from acids  

produced by bacteria metabolizing sugar, the hole is close to the  

pulp when it starts to hurt the person.

▪ Periodontitis: inflammation of the periodontal membrane that  

lines tooth sockets, this causes loss of bone and loosening of  

tooth

• Pharynx: the back of the throat

• Esophagus

• Stomach

• Small intestine: absorbs nutrients

• Large intestine: absorbs water

• Accessory organs: the ones that aren't part of the tubing (tract) • 5 processes necessary so that the digestive process happens: 1. Ingestion: taking of food or liquid into the body through the mouth 2. Digestion: breaking down of large nutrient molecules into smaller molecules  that can be absorbed

o Mechanical digestion: cutting and mastication of food, peristalsis o Chemical digestion: digestive enzymes hydrolyze macromolecules 3. Movement (mixing): food is passed from one organ to the next via peristalsis 4. Absorption: taking in of subunit molecules (like sugars, etc) by cells or  membranes. Happens in the small intestine

5. Elimination: process of expelling substances from the body via defecation  (pooping)

• Peristalsis: we don't have to think about our body digesting to make it happen, it  happens on its own.

• Reverse peristalsis: when there's something wrong with the food and makes us  vomit or expel it.

• Pharynx:  

• Fancy word for throat

• Portion of the GI tract between the mouth and esophagus

• Serves as a passageway for food and also air on its way to trachea (the  trachea is parallel and in front of the esophagus)

• Esophagus: muscular tube for moving swallowed food from the pharynx to stomach • Swallowing: composed of a voluntary phase and involuntary phase (reflex action): • Soft palate moves back to close off nasal passage via uvula. This is so that  food doesn't get into the nasal passage.

• Epiglottis: covers the glottis, which is the opening to the larynx (voice box). The  epiglottis is like a lid on the glottis, it opens up either the path to the trachea or the

esophagus. The epiglottis doesn't work when we are swallowing and laughing at the  same time.

• Peristalsis: wavelike contractions that propel the bolus along the esophagus (smooth  muscles in the GI tract)

• Sphincters: muscle that surrounds a tube to open or close by relaxing or contracting.  • Lower gastroesophageal sphincter: marks the entrance of the esophagus to  stomach. It contracts to prevent the stomach acids from going up the  esophagus (although, when this happens it's called heartburn)

• Heartburn: lower gastroesophageal sphincter fails to open and allow food to go into  the stomach or it fails to close and the stomach acids go up the esophagus. • Stomach: a muscular sac that mixes food with gastric juices to form chyme which  enters the small intestine:

• 1L capacity, has a pH of 2 (same as a car battery)

• Stores food, doesn't absorb nutrients. It empties 2-6 hours

• Initiates digestion of proteins with enzyme pepsin

• Controls the movement of food into the small intestine

• Gastric juice: produced by gastric glands of the stomach, includes pepsin  mucus and hydrochloric acid (HCl)  

• The HCl destroys bad bacteria that enter in the food

• Chyme: thick semi-fluid food material that passes from stomach to the small  intestine

• Pyloric sphincter: regulates chyme entry into the small intestine

• The first place that chemical digestion happens is in the mouth, then in the stomach. • Pancreatic juice joins with the bile

• Small intestine:

• Long tube-like chamber of GI tract between stomach and large intestine • Contains enzymes secreted by pancreas and enters via duct in duodenum to  digest carbs, fats and proteins

• Receives bile produced by the liver and is stored by the gallbladder that is  released into the duodenum. The bile breaks things down into small globules  • Parts:

o Duodenum: first 10 inches of the small intestine

o Jejunum: 2nd part of the small intestine, 8 feet long

o Ileum: 3rd part of the small intestine, 12 feet long

• Nutrients are absorbed by the small intestine

• Villus: small fingerlike projections of the inner small intestine wall (mucosa) o Outer layer has cells that have microvilli (brush border)

o Blood capillaries and small lymphatic capillaries (lacteal) are present. • Lactose intolerance: inability to digest lactose because of an enzyme deficiency • People that aren't lactose intolerant are mutants, what is supposed to happen is that  

the only time that people are supposed to break down lactose was when they were a  baby so they could break down the mother's milk. But after a mutation, the gene that  stopped the breakdown of lactose after being a baby was changed in some people  so that people can breakdown lactose their whole lives.

• Accessory organs:

• Pancreas: internal organ that produces digestive enzymes, it also produces  hormones insulin (helps lower sugar levels) and glucagon (helps elevate  sugar levels). Produces pancreatic juice that contains:

o Pancreatic amylase: enzyme in the pancreas that digests starch to  maltose

o Trypsin: protein-digesting enzyme  

o Lipase: fat-digesting enzyme secreted by the pancreas

• Bile: emulsification agent that is produced by the liver and stored in the gallbladder.  It splits one big globule into tiny droplets of fat that are easier to break down. • Test question: what is the enzyme responsible for breaking down proteins in the  stomach? Answer: pepsin.

• Accessory organs: they don't make up the tubing of the GI tract

• Pancreas: produces pancreatic juice that has 3 important enzymes:  pancreatic amylase, trypsin and lipase. The pancreatic juice is dispersed into  the duodenum in the small intestine.

o Glucose is stored in the human body as glycogen

o Plants store glucose as starch

o Diabetes:

▪ Type 1: pancreas doesn't produce enough amounts of insulin  

(so the glucose can't get into the cells), typically diagnosed  

before 15 years of age

▪ Type 2: pancreas doesn't make enough insulin or the body's  

cells are insulin resistant, typically diagnosed after 40 years of  

age

• Liver: dark red internal organ that:

o Detoxifies blood: hepatic portal vein brings food to liver from the GI  tract capillaries

o Stores glucose as glycogen, iron, vitamins A,D,E,K and B12

o Produces plasma protein and urea  

o Produces bile (that is stored in the gallbladder)

o Regulates cholesterol

o Liver diseases:

▪ Jaundice: skin turns yellowish from abnormal bilirubin (bile  

pigment) in blood meaning the liver is malfunctioning

▪ Hepatitis: inflammation of the liver, often caused by the Hepatitis  B virus

▪ Cirrhosis: chronic irreversible injury to the liver tissue, caused by  excessive alcohol consumption over long periods of time and  

Hepatitis C virus.

• Large intestine: last major portion of the digestive tract that extends from the small  intestine to the anus and contains:

• Cecum: the vermiform appendix is at the end of the cecum, the cecum is a  blind pouch at the beginning

• Vermiform appendix: small tubular appendage that extends out from the  cecum that aids in fighting infections. If the appendix is infected it is removed  because the infections it fights might explode into the body

• Colon: major portion of the large intestine, consists of the ascending colon,  transverse colon, descending colon and sigmoid colon

• Rectum: terminal end of the digestive tube, last 20 cm of the large intestine,  stores feces

• Anus: outlet of the digestive system, where excretion occurs

• Main function: absorb water

• DOES NOT absorb nutrients, only vitamin K and B complex

The Skeletal System: 

• System of protection and support

• The skeleton is composed of bones, cartilages (prevents the bones from rubbing),  joints and ligaments (connect bones together)

• Skeleton starts forming when the embryo is 6 weeks old

• 206 named bones in the skeletal system

• Make up 20% of body weight

• Tendon: connects bone to muscle

• Functions:

• Supports the body

• Protects soft body parts (heart)

• Produces blood cells

• Stores minerals (calcium and phosphate, these are what human bones are  made of) and fats (fat is stored in the middle of the bone in yellow bone  marrow)

• Allows flexible body movement (along with the muscles)

• Parts of the skeleton:

• Axial skeleton: main axis, forms the long axis of the boxy and includes the  bones of the skull vertebral column and the rib cage

• Appendicular skeleton: consists of bones of the limbs

• Cartilage: white flexible semi opaque connective tissue, chondrocytes (exocytosis of  matrix that makes the cartilage) are the mature cell form of cartilage, has no nerves  or blood vessels, it prevents bones from rubbing each other. Takes long to repair

• Ligament: band of fibrous tissue that connects bone to bone, has cells called  fibroblasts

• Tendons: cord of fibrous tissue attaching muscle to bone, has cells called fibroblasts • Every week we recycle 5 to 7% of our bone mass

• Chemical composition of bones:

• Organic components: osteoblasts, osteocytes and osteoclasts. They are  composed of living tissue.

o Osteoblast: they form the bone by exocytosis of matrix and they  promote the deposition of calcium salts into the matrix

o Osteocytes: maintain the structure of the bone, they are mature bone  cells derived from osteoblasts

o Osteoclasts: large cells that reabsorb or break down bone matrix, they  assist in returning calcium and phosphate to the blood. These acts  when there is a weak bone. Also these are the cells that allow the body  to grab calcium from bones if it needs it

• Inorganic components: hydroxyapatites (mineral salts), largely composed of  calcium phosphate.

• When we don't ingest enough calcium, the body needs it so bad that it grabs it from  the bones.

• Ossification: formation of bone

• Structure of a long bone:

• Compact bone: highly organized and composed of tubular units called  osteons (like coffee stirs) These have osteocytes that occupy small cavities  (lacunae). Canalicuni connect lacunae to one another and to the central  canal. The central canal contains small blood vessels and nerve fibers.

• Spongy bone: has an unorganized appearance. Its composed of numerous  struts or thin plates (trabeculae) separated by uneven spaces, these spaces  are often filled with red bone marrow

• Intramembranous ossification: flat bones that develop between sheets of embryonic  fibrous connective tissue membranes e.g. skull clavicles and mandible • Endochondrial ossification: happens in long bones: arms and legs: occurs at 6  weeks into the embryo. First a cartilage model is formed, then it grows, then there's  a development of primary ossification center (spongy bone) (starts to provide  resources for the bone to form), then the medullary )marrow) cavity develops, then  the secondary ossification center (happens after the baby is born), lastly the  formation of articular cartilage and epiphyseal plate (cartilage lining). • When do our bones stop growing: Girls on average 18 and boys on average 21. • Muscle types;

1. Smooth muscle: consists of spindle shaped, nonstriated muscle cells: they  are located in the walls of hollow internal organs and blood vessels, has a  single nucleus in cell, involuntary muscle that is slow to react, does not fatigue  easily.

2. Cardiac muscle: specialized muscle lf the heart, striated (areas of dark light  dark light dark light),has 1 or 2 nuclei per cell, cardiac cells interlock at  intercalated disks, involuntary muscle

3. Skeletal muscle: composed of cylindrical multinucleate cells with obvious  striations, consists of muscles attached to the body's skeleton, voluntary  muscle.

• Functions of Skeletal Muscle:

• Support: allows us to stand erect

• Movement of bones and other body structures

• Maintenance of constant body temp

• Movement of fluids in the cardio and lymphatic systems

• Protection of internal organs and stabilization of joints:

o Muscles pad the bones

o Muscular wall in abdominal region protect internal organs

o Muscle tendons

• How do muscles move bones?

• They work in pairs:

o Each muscle is concerned with the movement of only 1 bone

o When muscles contract they shorten

o Muscles can only pull, not push

• Origin: the end of a muscle attached to a stationary bone  

• Insertion: the end of a muscle attached to a movable bone

o When muscle contracts it pulls on tendons at its insertion and the bone  moves

o The nervous system stimulates an appropriate group of muscles o EG: the prime mover and synergists

• Antagonist: muscle that acts opposite another muscle (eg: bicep and triceps)  photo

• Structures of muscle cells:

• Sarcolemma: plasma membrane of a muscle fiber, forms the tubules of the T  system. Encases hundreds to thousands of myofibrils

• T (transverse) tubules: membranous channel that extends inward toward  sarcoplasmic reticulum

• Sarcoplasmic reticulum: smooth endoplasmic reticulum of muscle cells.  Surrounds myofibrils and stores calcium ions

• Myofibril: rod-like bundle of contractile filaments found in muscle cells. They  are made out of repeating units called sarcomere (they lie between z lines, as  seen in the picture)

• Hierarchical order of a muscle:

1. Fascicle: a bundle of muscle fibers surrounded by connective tissue 2. Muscle fibers (Myofiber): muscle cells

3. Myofibrils: contractile portion of muscle fiber (cells) that contains a linear  arrangement of sarcomeres

▪ They run the entire length of the muscle (so they are as long as your  bicep or triceps etc)

▪ They are composed of even smaller myofilaments

4. Myofilament: responsible for the actual contraction of muscles.  

▪ Sliding filament model: muscle contraction based on the movement of  actin fibers in relation to myosin filaments.

▪ Two types:

1. Actin: makes up thin filaments in myofibrils.

2. Myosin: one of the contractile proteins of muscle. Makes up  

thick filaments in myofibrils. They have little arms going out of  

the sides and at the end of each arm there's a myosin head, and  

these are like tugging and pulling the muscle in opposite  

direction to contract the muscle. Picture.

5. Sarcomeres: the smallest contractile portion of muscle that is arranged  linearly within myofibril and extends from one z line to the next z line. • Neuromuscular junction:  

• Where the axon of a motor neuron is attached to a muscle.  

• The axon terminal communicates with the muscle through neurotransmitters.  • The muscle has ligand gated channels that allow the sodium to rush in and  cause the action potential to move along the muscle until it hits the  sarcoplasmic reticulum which releases calcium.  

• There's tropomyosin, that's like a rope that covers the myosin binding sites  (what causes the myosin to grab onto the actin and contract the muscle).  • Attached to the tropomyosin are troponin, and these are turned on by calcium,  when this happens it lifts the tropomyosin up and allows the myosin to bind to  the actin and contract the muscle.

• Rigor mortis: when a person or animal dies and the limbs stiffen out because of a  chemical change in the muscles.

Immunity and Lymphatic system: 

• Lymph organs: organ of lymphatic system other than lymphatic vessels

• Primary: red bone marrow and thymus gland

• Secondary: lymph nodes, spleen, tonsils, appendix and Peyer's patches • Red bone marrow: produces red blood cells, like:

• Leukocytes (allergies, especially pollen): neutrophils (phagocytosis),  eosinophils and basophils (both degranulate, throw chemicals at things that  shouldn't be in the body). These are like the "common people in the castle"

• Lymphocytes: B cells (mature in bone marrow and produce antibodies), T  cells (mature in thymus), natural killer cells. These are like the "military, king's  guard".

• Thymus: involved in the maturation of T cells, only about 5% pass autoreactivity test.  Located between the trachea and the sternum superior to the heart. • Spleen: stores and filters blood; macrophages phagocytose pathogens and debris.  Largest lymphatic organ

• Lymph nodes: mass of lymphatic tissue located along the course of a lymphatic  vessel, macrophages phagocytose pathogens and debris.

• Tonsils: patches of lymphatic tissue, first to encounter pathogens • Peyer's patches: lymphatic tissue located within the appendix and encounters  pathogens.

• Autoimmune disease: when your own body attacks itself. The thymus is responsible  so that this doesn't happen.

• One of the functions of the lymphatic vessel is to pick up what the circulatory system  leaks out:

Immune system:

• Functional system whose components attack foreign substances or prevent their  entry to the body

1. Innate immunity: skin, mucous membranes. A mechanism of defense that doesn't  depend on prior exposure to the invader, nonspecific (broad) (the skin protects  against everything). Immediate.

a. First line of defense:

▪ Skin: layer of protection associated with the innate immunity system.  Like the castle wall. Oil and sweat glands give skin surface pH of 3-5,  sweat contains lysozyme (digests bacterial cell wall), normal flora  

include non-pathogenic bacteria and fungi, epidermis 10-30 cells thick  and dermis 15-40 times thicker.

▪ Mucous membranes:  

1. Digestive tract: saliva contains lysozyme (also found in tears),  

acidic environment of stomach pH of 1.5-3.5, digestive enzymes  

in intestine, nonpathogenic normal flora, vomiting and diarrhea  

may expel pathogens.  

2. Respiratory tract: pathogens trapped by mucus in bronchi and  

bronchioles, ciliated epithelial cells sweep mucus toward the  

glottis, coughing and sneezing expels pathogens.

3. Urogenital tract: vaginal secretions viscous and acidic,  

secretions promote growth of normal flora, acidic urine of both  

sexes may wash out pathogens.

2. Adaptive (acquired) immunity: specific to the particular non-self material, requires  time for development, occurs more quickly and vigorously on secondary response.  • Second line of defense: phagocytes, inflammation, complement and  interferon, chemical signals:

o Recognize a wide spectrum of pathogens without a need for prior  exposure

o Key players include neutrophils, monocytes that become macrophages o These cells phagocytose pathogens and trigger the release of  

cytokines (chemical signals, protein hormones that let other immune  system "soldiers" or cells where the problem is)

o Results in inflammation and specific immune responses

o Inflammation: occurs over seconds, minutes, hours and days

▪ Histamine: chemical that dilates blood vessels

▪ Bradykinins: make the spaces that make the blood vessels  

leaky even larger so there is more leakage

▪ Prostaglandins: responsible for the pain (eg: sunburnt skin pain) 1. Dilation of blood vessels increases blood flow at site (RED &  

WARM)

2. Increased permeability of capillaries causing edema (tissue  

SWELLING). This allows the cells to move to the site of the  

harm quicker.

3. Tissue swelling puts pressure on nerve endings (PAIN and  

potential loss of function)

4. Macrophages and neutrophils release cytokine tumor necrosis  factor (TNF) which acts on hypothalamus to raise the body temp  (fever)

5. Cell death (necrosis) always occurs to some degree during  inflammation

o Complement: 30 proteins that are produced by the liver. They circulate  freely in blood plasma. When activated, one forms a domino effect on  another causing a cascade of events that form a membrane attack  complex (MAC) that form pores in pathogens that have lipid membrane  to induce lysis (causes the bad bacteria to explode by making holes in  its membrane)

o Interferon: antiviral agent produced by an infected cell that blocks  infection of an uninfected cell (degrades RNA and blocks protein  production). It works especially with virus. Type of cytokine.

o Cytokines: protein hormones used by immune cells to communicate.  Can affect same cells that produce them, cells nearby or cells distant in  body. EG: interferon.

• Third line of defense: ADAPTIVE IMMUNITY

o Important aspects of the immune response:

1. Non-self recognition: ability to distinguish self-antigens from  non-self

???? Antigen: foreign substance that stimulates and immune  

response. EG: dust, pollen

???? Antibody: protein produced in response to the presence  

of an antigen

2. Antigen-specific: recognizes and is directed against specific  antigens

3. Systemic response: immunity is not restricted to initial infection  site

4. "Memory": recognizes and mounts stronger attack on previously  encountered pathogens.  

o Major histocompatibility complex (MHC): cell surface glycoproteins,  polymorphic. Think of them as flag poles on the surface of cells. Only T  cells can decipher them.

▪ MHC class 1 protein: found in eukaryotes (cells that have  

nucleus), has cytotoxic T cells (CD8) respond to endogenous

antigen (generated inside the cell) bound to MHC class 1  protein. The CD8 is the only cell that understands the signal.  When the CD8 connects with an infected cell and realizes that  something is wrong, it produces cytokines that communicate  with the infected cell through its own cytokines which cause the  CD8 to clone itself and attack the infected cell until it causes  apoptosis (to explode)

▪ MHC class 2 protein:

???? Found only on professional antigen presenting cells like  Macrophages and B cells

???? Helper T cells (CD4) respond to exogenous antigen  

(comes from outside the cell) bound to MHC class 2  

proteins

???? When bacteria is engulfed by macrophages, the Helper T  cell connects with the macrophages, then clones itself,  

and then has 2 choices: to produce a humoral response  (communicates with a B cell that clones and the "general"  (CD4) signals them to fire their arrows towards the  

infected cell) or a cellular response (it "juices up" the  

macrophage and destroys the bacteria)

o Two overlapping arms of immunity:

▪ Cell-mediated immunity: (like hand to hand combat), associated  with cell surfaces, T-cell receptors that are unable to see free  antigens

???? T cells: 2 main types that include CD8 (directly attack  cells that carry specific antigens) and CD4 (regulate  

immune responses of other cells, they are like the  

"general" during battle)

• Produced in red bone marrow, they migrate to the  

thymus to mature and be selected

• T cell receptors recognize antigen presented on  

self MHC molecules

▪ Humoral immunity: (like archers shooting arrows), based on  antibodies on cell surfaces and in body fluids (blood, lymph,  etc).

???? B cells: bind to specific antigen with its antibody (B cell  

receptor) and also serve as antigen presenting cell to  

Helper T cells. They are produced in red bone marrow.  

Immunoglobulin synthesis happens in bone marrow.  

Tested for accuracy in red bone marrow as well. Types:

• Plasma B cells: are large B cells that have been  

exposed to antigen, they produce and secrete  

large amounts of antibodies, are short lived cells  

that undergo apoptosis

• Memory B cells: are specific to the antigen  

encountered, they live for a long time and can  

respond quickly following a second exposure to  

the same antigen.

• HIV (Human immunodeficiency virus): a retrovirus that attacks the body's immune  system, causes AIDS.

• HIV mounts direct attack on TH cells by binding to CD4 proteins on cell surface • HIV kills TH cells faster than they can proliferate over time

• When CD4 and T cell numbers decline bellow 200 cells per microlitre of blood, the  cell mediated immunity is lost.

Respiratory System: 

• Ensures oxygen enters body while carbon dioxide leaves body

• Composed of:  

• Upper respiratory tract: conditions air as it enters the body.  

o Nasal cavity: air is humidified, heated. Has flaps of tissue. Has large  hairs that filter air and mucus membranes that produce mucus.  

Capillaries of sub-mucosa warm and moisten air. Tear (lacrimal)  

glands drain into the nasal cavity (when we cry we get runny noses  because the tears that don't drip out of our eyes go to our nose, this  helps clean the nasal cavity.

o Pharynx: place where pathways for air and food cross. Connects nasal  and oral cavities to the larynx,

▪ Tonsils: primary defense during breathing

▪ Epiglottis: covers the entrance to the larynx. Prevents food from  going to the larynx. Like the doors to the larynx (they open and  

close)

▪ Uvula: tab of tissue at the back of throat it contracts when  

touches by food and prevents food from going into the nasal  

cavity.

o Glottis: entrance to the larynx (covered by the epiglottis). Like the  doorway to the larynx.

o Larynx: voice box. Cartilaginous organ between pharynx and trachea. ▪ Vocal cords: fold of tissue that vibrates to create vocal sounds]

▪ Glottis: opens air flow in the larynx

• Lower respiratory tract: allows oxygen to enter the blood and waste gases to  leave blood.  

o Trachea: windpipe, passage of air to bronchi. In front of the esophagus  so that when we eat something big there's room for the trachea to  

move and not collapse. Consists of connective tissue, smooth muscle  and cartilaginous rings. Has mucosal membrane that produces mucus  (from goblet cells) and is lines with cilia that push the mucus upward. o Bronchus/Bronchi (plural): passage of air to lungs  

o Bronchioles: passage of air to alveoli  

o Lungs: contain alveoli (air sacs lined with surfactant which reduces  water tension) that carry out the gas exchange. The right lung has 3  lobes and the left one has 2 because of the cardiac notch.

o Diaphragm: skeletal muscle, functions in ventilation. What separates  the abdominal cavity from the thoracic cavity. When we inhale it  

pushes down because the lungs expand and when we exhale it pushes  up because the lungs compress.

• The groups of alveoli are called lobules.

• The pulmonary artery takes deoxygenated blood to the capillaries of the alveoli and  then the pulmonary vein takes oxygenated blood from the capillaries of the alveoli to  the heart.

• Air (oxygen) gets into the capillaries that go to the alveoli by diffusion. It goes from a  high concentration in the capillaries to a lower concentration inside the alveoli. • External respiration: pulmonary gas exchange. CO2 from the capillaries is  exchanged for O2 by the alveoli.

• Internal respiration: systemic gas exchange by systemic tissue cells. Oxygen goes to  tissue cells in organs and is exchanged for CO2 which goes into the capillaries •

• Our cells produce CO2 when they do cellular respiration and when they separate  glucose molecules. This is the CO2 that will be exchanged for the O2. It's also  exchanged through diffusion

• The right side of the heart pumps deoxygenated blood.

• If we didn't have a diaphragm we could not breathe

• Valsalva maneuver: forceful attempt to exhale against a closed airway, like pinching  the nose shut and closing the mouth while pressing out air as if blowing a balloon.  This is done to equalize air pressure.

• Spirometer: measures the volume of air that is inspired and expired by the lungs. • Total capacity of the lungs is 5800 ml.

• Tidal volume: normal, shallow breaths. They amount 5000 ml approx. • There's always some air left in the lungs because if we get rid of all of the air, then  the lungs collapse. This air is called residual volume. When someone "knocks the  wind out of you", you can't breathe, you lost some of the residual volume.

4/28/16 11:22 PM

Urinary System: 

• Organ system consisting of the kidneys and urinary bladder.

• Excretion: rids the body of nitrogenous waste and metabolic waste • Helps regulate the water-salt balance of the blood. It filters the blood • Urea: primary nitrogenous waste of human derived from amino acid breakdown

• Kidneys: organ of the urinary system that produces and secretes urine • Fist sized organ

• Produces hormone called calcitriol which increases blood calcium levels • Produces hormone called erythropoietin which stimulates red blood cell  production

• The outer part is called the renal cortex. Appears granular

• Renal medulla: has the renal pyramids, the inside part of the kidney. • Renal pelvis: hollow chamber of the kidney that lies inside the renal medulla  receives freshly prepared urine and takes it to the bladder.

• Renal artery: vessel that transports blood to be filtered from the aorta and  delivers it to our body

• Renal vein: vessel that takes filtered blood away from the kidney to the  inferior vena cava.

• Ureters: one of 2 tubes that take urine from the kidneys to the urinary bladder. is  25cm long and 5mm in diameter

• Urinary bladder: organ where urine is stored, approx. 800ml.

• Has small folds of mucosa that prevent backward flow to ureters. When there  is backward flow, the kidneys stop working

• Internal sphincter (involuntary) and external sphincter (voluntary) • Approx. 300ml stretch receptors send the 1st nerve signal to the CNS. (when  300ml go into the bladder, it stretches and causes the internal sphincter to  give way and the urine starts going down to the urethra. But there's an  external sphincter that prevents it from going any further, it's the feeling we  get when we need to pee but are holding it for a while.

• When the bladder gets to 800 ml, you're gonna pee your pants.

• It takes until a person is 3 or 4 years old to be able to control the external sphincter • Urethra: tubular structure that receives urine from the bladder

• Carries urine to the outside of body

• Micturition: emptying of the bladder, urination, peeing.

• Nephrons: (where the action takes place, the filtration) microscopic kidney unit that  regulates blood composition by:

1. Glomerular filtration

2. Tubular reabsorption

3. Tubular secretion

• The part of the kidney where the filtration actually happens is the Nephron.  • Nephron:  

• Glomerulus: capillary bed, ball shaped, surrounded by the glomerulus capsule  where glomerular filtration takes place. There's more leakage than other  capillaries. Water, salts, uric acid, glucose and other molecules leak out and  enter the proximal convoluted tubular

• Glomerulus capsule: double walled cup that surrounds the glomerulus • Peritubular capillary network: capillary network that surrounds a nephron and  functions in reabsorption during urine formation. Purple tubes seen around  the nephron in the picture above.

• Proximal convoluted tubule: next to the glomerular capsule. The things that  got filtered out in the glomerulus but that we need like glucose and amino  acids are put back into the capillaries by Tubular Reabsorption. Inside it has  villi which increase surface area.

• Loop of the nephron: where we get water that got filtered out, found between  the proximal and distal convoluted tubules. Water reabsorption takes place. • Distal convoluted tubule: distant to the glomerulus. The toxins and other  things that didn't get filtered out of the blood are taken in by this tubule from

the capillary next to them through active transport called Tubular Secretion  (only for toxins or things that should be removed from blood flow).  

• Collecting duct: once anything reaches here it becomes part of the urine and  will be excreted from the body in hours.

• Afferent arteriole (brings blood to the glomerulus) is much larger than the efferent  arteriole(takes blood from the glomerulus to the peritubular capillary network), this  puts the capillary bed under a lot of pressure which pushes the liquids to go out  faster.

Endocrine System: 

• Organ system that includes internal organs that secrete hormones • Endocrine gland: a ductless gland that secretes hormone(s) into the bloodstream.  EG: pituitary, thyroid, adrenal, etc

• Exocrine gland: glands that have ducts through which their secretions are carried to  a particular site. Eg: mucous, sweat, oil and salivary glands, the liver (secretes bile) • The pancreas is both exocrine (secretes digestive enzymes through pancreatic juice  through a duct) and endocrine (secretes insulin and glucagon to the bloodstream, no  duct)

• Hypothalamus: master gland because it has control over the other glands in the  body

• Hormone: protein or steroid produced by a cell that affects a different cell (target  organ). Only cells with receptors for a particular hormone can respond to it (like the  cells have a lock that can only be accessed by a certain key which is a certain  hormone). Hormones communicate through chemical signals. They leave the  capillaries through leakage. Types of hormones:

• Peptide hormone:

o Hormones that are peptides, proteins or modified amino acids.  o They work super fast but are not long lasting. EG: adrenaline  

(epinephrine)

o They bind to receptors on the plasma membrane (not allowed inside  the cell)

o 1st messenger: hormone bound to plasma membrane (doesn't enter  cell)

o 2nd messenger: mediates intracellular response

o Class example: boys night, the guys need a pizza cutter so one of  them calls his girlfriend to bring it to them, she does but they don't let

her come in because she is a girl and they are in a boys only night.  (the girlfriend is the 1st messenger and the pizza cutter is the 2nd  

messenger).

• Steroid hormone:

o Hormones derived from cholesterol. EG: testosterone (puberty)

o They enter cell via plasma membrane

o Goes into the nucleus and binds to a receptor, and the receptor knows  where to put it into the nitrogenous bases, as a result there's more  production of mRNA of a certain gene.

o They act more slowly, but last longer

o Only produced by adrenal cortex, ovaries and testes.

o Class example: the girlfriend got mad because she wasn't allowed in.  So the boyfriend has to redeem himself and organizes her a night with  her friends and offers to make them a pizza from scratch.

• Pheromones: chemical signal released by an organism that affects the metabolism  or influences the behavior of another individual of the same species. How animals of  the same species recognize themselves (they can't talk with each other so this is  how they find the right mate). Through pheromones, women can sync their  menstrual cycles.

• Negative feedback: mechanism of homeostatic response in which a stimulus initiates  reactions that reduce the stimulus (what the body does to maintain homeostasis)  EG: body temp regulation (through sweating when hot or shaking when cold for  example).

• Positive feedback: the goal is to get a job done even if it means getting out of  homeostasis. The stimulus initiates reactions that lead to an increase in the stimulus.  For example: lactation (when the baby is suckling, more milk is released) and child  birth (when more pressure is put on the cervix, more oxytocin is released which  causes more contractions that cause the vagina to dilate), blood clots, orgasms. • Hypothalamus: "master gland"  

• Link between the nervous and endocrine systems.  

• Regulates internal environment of the body.  

• Controls secretions of the anterior pituitary, which controls secretions of the  thyroid, adrenal cortex and gonads.  

• Produces 2 hormones stores and secreted by the posterior pituitary: o Antidiuretic hormone (ADH): stimulates kidneys to reabsorb more  water reducing urine volume. (during dehydration)

o Oxytocin: stimulates contraction of the uterus during childbirth and  ejection of milk during nursing.

• Pituitary gland: connected to hypothalamus, consists of anterior and posterior  pituitary. The anterior produces: (think of All Friendly Girls Like To Meet People) 1. Adrenocorticotropic hormone (ACTH): stimulates the adrenal cortex to  produce cortisol

2. Follicle-stimulating hormone (FSH): stimulates ovarian follicle production in  females and sperm production in males

3. Growth hormone (GH): promotes skeletal and muscular growth

4. Luteinizing hormone (LH): aids maturation of cells in the ovary, triggers  ovulation. Causes interstitial cells of testes to produce testosterone. 5. Thyroid stimulating hormone (TSH): regulates secretion of thyroid hormones 6. Melanocyte-stimulating hormone (MSH): stimulates production and release of  melanin (skin pigment)

7. Prolactin (PRL): stimulates breasts to produce milk.

• Thyroid Gland: endocrine gland in the neck that produces and secretes the following  hormones:

• Thyroxine (T4): promotes growth and development, increases metabolic rate • Calcitonin: decreases blood calcium level

• Parathyroid glands: embedded in the posterior surface of thyroid. A total of 4  parathyroid glands. Produces and secretes:

• Parathyroid hormone: increases the blood calcium level

• Calcitriol: hormone produced by the kidneys, so that the intestines can absorb  calcium easier.

• Pancreas: produces digestive enzymes and the hormones insulin and glucagon • Insulin: lowers blood glucose levels by promoting uptake by cells and  converting glucose to glycogen in liver and skeletal muscles

• Glucagon: raises blood glucose level by causing the liver to break down  glycogen.

• Adrenal glands: found on top of each kidney, consist of inner adrenal medulla and  outer adrenal cortex

• Medulla: secretes the hormone epinephrine (adrenaline). This hormone is  short term effective.

• Cortex: secretes mineralocorticoids (like aldosterone) and glucocorticoids (like  cortisol). These hormones are for long term effect.

Reproductive system: 

• Organ system that contains male of female organs specialized in the production of  offspring

• Gonad: primary sex organs that produce gametes

• Ovary: produces eggs

• Testis: produces sperm

• Gamete: haploid sec cell, the egg or sperm which join in fertilization to join a zygote • Germ line cells: cells that are set aside from somatic cells during zygote  development. These cells will eventually undergo meiosis to produce gametes • Somatic cells: any human cells except those that are destined to form gametes • The average length of the un-stimulated vagina is 3.25 inches. When stimulated, the  vagina is 4.75 inches.

• Sperm can last in the female reproductive system for 4-5 days. The fertilized egg  lasts 6-24 hours.

• When women are born they already possess all of the eggs that they will ever need.  Once they reach puberty, a small amount of these eggs are chosen to develop  further.

• Males ejaculate between 2-5ml of semen (one teaspoon)

• Vasectomy: procedure that prevents sperm from going into the urethra because the  vas deferens is cut or knotted. Doctors make the most vasectomies in March  because of March Madness (basketball tournament).

• Spermatogenesis: A spermatogonium undergoes mitosis and produces 2 daughter  cells. One of these undergoes spermatogenesis while the other stays behind and  then that's the one that will do mitosis the next time.

• Male external genitalea: external (can be seen), penis and scrotum. The average  size of a penis is approx. 5.5 inches. 30% of the world, 75% in US, and 58% of  newborns today are circumcised.

• Male reproductive parts:

• Penis: organ for copulation and urination. Designed to deliver sperm to the  female reproductive tract

• Glans penis: enlarged tip of the penis

• Foreskin: loose skin covering penis that slides distally to form a cuff of skin  around glans. This is what's removed during circumcision.  

• Scrotum: pouch of skin that covers the testes. Hangs outside abdominopelvic  cavity. It's 3 degrees lower than the temperature inside the body.

• Testes: paired male gonads within the scrotum that produce sperm and male  sex organs. The testes are outside the body, inside the scrotum because if  they were inside the body, that temperature would not be ideal for sperm  production. If it gets cold outside, the scrotum pulls them closer to the body so  that they receive heat. Parts:

o

o Seminiferous tubules: long coiled tubules contained within chambers of  the testes, where sperm are produced. "Sperm factories"

o Spermatogenic cells: give rise to sperm and make up most of the  epithelial wall of the seminiferous tubules. Sperm is produced everyday  from puberty until death

o Interstitial cells: located in connective tissue surrounding seminiferous  tubules. They produce and secrete androgens (testosterone) into  

interstitial fluid.

o Epididymis: coiled tubule next to the testes where sperm mature and  may be stored for a short time. It serves as a final maturation center  and empties into vas deferens

o Vas deferens: tube that leads from the epididymis to the urethra in  makes and stores sperm up to several months.

• Accessory organs: paired seminal vesicles and bulbourethral glands and the single  prostate gland. They produce the bulk of semen

• Seminal vesicles: convoluted structure attached to the vas deferens. Adds  nutrients and 60% of fluid to semen

• Prostate gland: gland located around the male urethra below the urinary  bladder. Adds secretions to semen that help activate sperm

• Bulbourethral glands: 2 small structures located below the prostate gland.  Contributes mucus-containing fluid to semen. Neutralize traces of acidic urine  in the urethra prior to ejaculation. Lubricates glans penis.

• Semen: fluid mixture that contains sperm and secretions of the male accessory  reproductive glands. The pH is of 7 (basic), this is because the vagina is pH 4-5, so

the semen has this pH because it will neutralize the vagina's pH. Transport medium,  nutrients and chemicals that protect and activate sperm. 2-5ml (a teaspoon) fluid  containing 50-100 million sperm per ml.

• Chief phases of male sexual response:

• Erection: enlargement and stiffening of the penis allows penis to penetrate  vagina

o Parasympathetic reflex is triggered during sexual arousal:  

parasympathetic=relaxation of the body, so if you are stressed there's  going to be a parasympathetic reflex so that you can get aroused (if  you are stressed it's harder to get aroused)

o Promotes local release of nitric oxide that relaxes smooth muscle o Causes arterioles to dilate in erectile tissue

o Vascular spaces of erectile bodies fill with blood compressing veins. • Ejaculation: propulsion of semen from the male duct system, occurs when  impulses provoking erection reach critical level, spinal reflex is initiated. Aka  climax/orgasm: generates intense pleasure, muscle contraction, rapid heartbeat, elevated blood pressure.

o Reproductive ducts and accessory organs contract releasing contents  to urethra

o Bladder sphincter muscle constricts

o Muscles of penis undergo rapid contractions to propel semen from  urethra

• Female reproductive system:

• External:

o Vulva: all of the external genitals, consists of:

o Mons pubis: fatty rounded area covered with pubic hair

o Labia majora: posterior from mons pubis and consists of 2 elongated,  hair covered fatty skin folds. Female equivalent of the scrotum

o Labia minora: 2 thin, fair free skin folds enclosed by the labia majora.  Female equivalent of the ventral penis.

o Vestibule: area enclosed by the labia minora, has the urethra and  vaginal openings

o Clitoris: small protruding structure composed largely of erectile tissue  (meaning it enlarges during sexual stimulation-2 to 3 times as large)  located anterior to the vestibule. Female equivalent of the glans penis.

o Prepuce of the clitoris: hooded skin fold of the clitoris formed by the  junction of the labia minora folds

• Internal: consists of:

o Ovary: 2 ovaries, flank the uterus on either side, female gonad,  produces eggs and the female sex hormones (estrogen and  

progesterone)

o Uterine tubes/ fallopian tubes/ oviducts: tube that transports eggs to  the uterus:

▪ They extend fro the uterus to the ovaries but are not attached to  the ovaries

▪ Fimbria: finger like projections of uterine tube that sweep over  

ovary

▪ When the egg bursts out of the ovary during ovulation it is swept  into the oviduct by the fimbria and beating of cilia that line  

oviducts.

▪ Egg lives from 6-24 hours unless fertilization occurs.

▪ Fertilization usually takes place in the oviduct.  

Egg+sperm=zygote. A zygote is not enough to get pregnant,  

successful implantation has to happen.

o Uterus (womb): hollow, thick walled organ located in the female pelvis  where it receives retains and nourished a fertilized ovum.

▪ Developing embryo arrives at uterus several days after  

fertilization

▪ Implantation occurs when embryo embeds in prepared uterine  

lining

▪ Endometrium: mucous membrane lining the interior surface of  

the uterus

▪ Cervix: lower end of uterus, enters the vagina at nearly a right  

angle.

o Vagina: organ that leads from the uterus to the vestibule and serves as  the birth canal and organ of sexual intercourse in females.

• A pregnancy test looks for the presence of a hormone that's secreted by the zygote  (this hormone tells the body to prepare for pregnancy)

• The ovarian cycle: on the 14th day into the cycle ovulation happens.

• When fertilization is unlikely (before ovulation), the mucus in the cervix is going to be  very thick to form like a plug. When ovulation happens, the mucus becomes watery  so it allows sperm to go through easier.

• Sexual Female Response:

• Labia minora, vaginal wall and clitoris become engorged with blood (grow 2-3  times)

• Breasts swell and nipples become erect

• Labia majora enlarge, redden, spread away from the vaginal opening • Vaginal wall releases lubricating fluid

• Mucus-secreting glands beneath the labia minora also provide lubrication. • During orgasm: blood pressure and pulse rate rises, breathing quickens, and  the walls of the uterus and oviducts contract rhythmically without a refractory  period (this means that women can have multiple orgasms, something males  cannot have because they do have a refractory period)

• Ovarian cycle: monthly follicle changes occurring in the ovary that control the level of  sex hormones in the blood and the uterine cycle, repeats every 28 days • Uterine cycle: monthly occurring changes in the characteristics of the endometrium,  produced by the hormones that the ovaries produce (progesterone) • Primary oocyte: at birth a female has a lifetime supply of 700,000. They are stuck in  late prophase 1 of meiosis until selected and activated after puberty • Follicles: structure in the ovary that produces a secondary oocyte and the hormones  estrogen and progesterone. This secondary oocyte is stuck in metaphase 2 of  meiosis until it's fertilized.

• Estrogen: female sex hormone that helps maintain sex organs and secondary sex  characteristics (breast growth, hair under arms)

• Progesterone: hormone partly responsible for preparing uterus for the fertilized ovum • Secondary oocyte: product of meiosis 1, stuck in metaphase 2, is ovulated. • Oogenesis: production of an egg in females via meiosis

• Polar body: in oogenesis a non-functional product. 2 or 3 occur in meiosis. The  secondary oocyte becomes an egg

• Only one usable gamete is produced by the female reproductive system • Ovulation: release of a secondary oocyte from the ovary

• If fertilization occurs, the secondary oocyte becomes an egg (ovum) • Occurs in the middle of the ovarian cycle

• Usually 1 per month

• Stimulated by LH

• Corpus luteum: yellow body that forms in the ovary from a follicle that has  discharged its secondary oocyte, it secretes progesterone and some estrogen, if the  egg is fertilized it remains for 3 months until placenta takes over. This is necessary  during the beginning of pregnancy because the progesterone keeps the  endometrium strong and thick and stops it from coming down.

• Menstruation: loss of blood and tissue from the uterus at the end of the uterine cycle.  Women lose from 10-85 ml of blood. (35ml is the average)

• If two eggs were fertilized, the woman will have twins that aren't identical, for the  twins to be identical there has to be only one fertilized egg that splits into two  fertilized eggs.

• Human chorionic gonadotropin (hGC): hormone through which the embryo lets the  woman's body know that it was fertilized and that it has to nurture it now. Pregnancy  tests look for this hormone using an antibody that is directed against hGC in blood or  urine, because hGC in the woman's blood 1 week after fertilization. Secreted by  blastocyst, tells the corpus luteum to continue secreting progesterone and estrogen.

• Implantation: begins 6 days after ovulation, takes 1 week to complete. 50% chance  of success.

• Placenta: temporary organ formed from both fetal and maternal issues • Provides nutrients and oxygen to developing fetus

• Carries away fetal metabolic waste

• Produces the hormones of pregnancy

• Umbilical cord: structure bearing arteries and veins that connect the placenta to the  fetus (where the belly button is after birth)

• Gestation: period of pregnancy. About 280 days

• Menopause: ovulation and menstruation cease. Prompted by hormonal changes,  usually occurs between 45-55 years old. A whole year without menstruation. • Contraceptives: medication or device used to reduce the chance of pregnancy • Birth control pills: oral contraceptive containing estrogen and progesterone,  shuts down the pituitary production of LH (the one that produces ovulation)  and FSH, follicle development is prevented (no ovulation). Tricks the body  into thinking it's already pregnant so it does not ovulate.

• Intrauterine device: small piece of plastic or copper inserted into the uterus,  alters uterine environment so fertilization does not occur.

• Diaphragm: soft rubber or latex cup that fits over cervix used with spermicidal  jelly. This blocks the entrance to the vagina so that the sperm do not get in,  especially when they are killed with spermicidal jelly.

• Female condom: large polyurethane tube that with a flexible ring fits onto  cervix

• Male condom: latex sheath that fits over erect penis

• Contraceptive implants: uses synthetic progesterone to prevent ovulation, can  remain effective for about 3 years.

• Contraceptive injection: uses progesterone and/or estrogen to disrupt the  ovarian cycle. Not long term, effective for several months.

• Emergency contraceptive pills (ECPs): known as the morning after pill o Plan B (Levonorgestrel) is a way to prevent pregnancy after  

unprotected sex

o Prevents ovulation, may prevent a fertilized egg from implanting o No prescription needed if older than 16, works up to 72 hours after  intercourse

o Not to be confused with mifepristone (RU486, Mideprex): "abortion pill" • Sterility: inability to reproduce (permanently)

• Vasectomy: both vas deferens are cut and sealed

• Tubal ligation: uterine tubes are cut and sealed.

Sexually Transmitted Diseases: 

• Sexually transmitted disease (STD): an illness that has a significant probability of  transmission by means of human behavior including but not limited to: vaginal  intercourse, oral sex and anal sex. They can be viral, bacterial, fungal, protist and  animal origin.

• Most effective way to prevent them: abstinence from sexual relations. Techniques to  help reduce the risk of STDs include:

• Having sex only with people who have testes negative for STDs • Remaining in a mutually monogamous relationship that started free of STDs • Using barrier techniques, primarily condoms that reduce risk of STD  transmission

• For sexually active people with multiple partners, getting vaccinated (although  vaccines are not available for all STDs).

• Viral STDs:

• Hepatitis:

o A:  

▪ usually acquired by contaminated drinking water, but also  

sexually by anal-oral contact.

▪ Symptoms appear 2-7 weeks after exposure, they include  fatigue, fever, sore muscles, headache, nausea, weight loss,  

jaundice, liver pain.  

▪ Does not result in chronic infection. (Antibodies confer  

protection against reinfection)  

▪ There is a vaccine for it

o B:

▪ Spreads through sexual contact and by blood-borne transfusion ▪ Symptoms appear 6 weeks-6 months after exposure

▪ Symptoms similar to Hep. A and may include skin rash, diarrhea  or constipation.

o C:

▪ Not efficiently transmitted sexually

▪ Most common chronic blood-borne infection in the United States ▪ Chronic (can return)

▪ Even though there's a vaccine for Hepatitis A and B, there is  none for hepatitis C

• Herpes: viral STD caused by herpes simplex viruses type 1 or type 2 o Type 1: Usually causes cold sores and fever blisters

o Type 2: most genital herpes is caused by it. It can still be transmitted  even though if there is no visual sign of an outbreak. Symptoms: o May occur 2 weeks after exposure, the blisters rupture leaving painful  ulcers that take 5 days to 3 weeks to heal

o Blisters may be accompanied by fever, pain on urination, swollen  lymph nodes in groin, copious discharge in women

o Usually 4-5 outbreaks a year

o No cure but there's medication that can reduce the outbreaks. • HPV (Human Papillomavirus): causative agent of genital warts o Warts are located on the penis and foreskin in men and near the  vaginal opening in women

o Visible warts may be removed by surgery, freezing or burning with  laser or acids

o Removed warts may recur

o A newborn can become infected while passing through the birth canal o Genital warts are associated with the cancer of the cervix as well as  tumors of the vulva, vagina anus and penis

o There is a vaccine but it only defends against some strains of the virus,  not all of them

o HPV Vaccine (Gardasil): protects against types, 6,11,16 and 18. Types  6 and 11 are associated with warts. Types 16 and 18 are associated  with cancer.

• HIV (Human immunodeficiency virus): retrovirus that attacks the immune  system

o Causative agent of AIDS: Acquired Immune Deficiency Syndrome o HIV infects cells of the immune system

o HIV mounts direct attack on helper T cells

o Monocytes are also infected

o HIV kills T helper cells (CD4) faster than they can proliferate over time o T cell count under 200 cells per microliter means cell-mediated  immunity is lost (AIDS)

• Bacterial STDs: sexually transmitted diseases caused by bacteria • Gonorrhea: caused by the bacterium Neisseria gonorrhoeae

o Symptoms usually appear 2-5 days after infection

o Males: easy to diagnose, pain upon urination and thick, greenish  yellow urethral discharge

o Infection may lead to pelvic inflammatory disease which can cause  sterility in both sexes

o Can spread to internal body parts causing heart damage and arthritis o If a baby is exposed at birth an eye infection may result in blindness o 40% of all strains are now resistant to therapy

• Syphilis: involves 3 stages

o Stage 1: a hard chancre indicated site of infection, usually heals  leaving little scarring

o Stage 2: victim breaks out in rash over body that does not itch, hair  loss, infectious grey patches on mucous membranes, these symptoms  disappear on their own

o Stage 3: lasts until the patient dies, may affect the cardiovascular  system resulting in aneurysms, may affect the nervous system  

resulting in psychological disturbances, large gummas appear on or  within certain organs, penicillin is an effective antibiotic.

• Chlamydia:

o Symptoms are usually mild or asymptomatic, especially in women

o 18 to 21 days post infection men may experience mild burning  sensation upon urinating and a mucoid discharge

o Women may have vaginal discharge along with symptoms of urinary  tract infection, also causes cervical ulcerations

o Can lead to pelvic inflammatory disease

• Fungal STDs:

• Candida Albicans: yeast infection

o Candida normally lives harmlessly on skin in mouth intestines and  vagina when kept under control by normal bacterial flora

o When conditions in the body change to favor Candida growth,  symptoms may occur. Like nylon underwear or tight clothing, taking  certain antibiotics, bubble baths.

o Can also be transferred between sexual intercourse

o Symptoms in women include itching, redness and soreness around  vagina vulva and anus as well as a cottage cheese like discharge o Symptoms in men include itching under foreskin or at tip of penis,  discomfort when urinating, unusual cottage cheese like discharge o The antifungal drug clotrimazole commonly used

• Protozoan STDs: caused by protists

• Trichomonas vaginalis: single celled flagellated protozoan STD o Vagina most common site of infection in women

o Urethra most common site of infection in men

o Transmitted through sexual intercourse

o Symptoms occur 5 to 28 days post exposure

o Most men are asymptomatic or have slight burning upon urination or  mild discharge

o Symptoms in women include frothy, yellow green vaginal discharge  with strong odor called leukorrhea

• Animal STDs: caused by insect

• Phthirus pubis ("Crabs")

o Insects called crabs that are about 1.5-2 mm in diameter

o Notorious for infesting human genitals where they feed exclusively on  blood

o Main symptom is intense itching in pubic hair area because of  hypersensitivity to louse saliva

o Can be treated with permethrin 1% cream rinse, shaving off hair or  using a fine toothed comb

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