Ch 18 cont'd, Ch 19 Blood
Ch 18 cont'd, Ch 19 Blood BIOL 224
Popular in Human Anatomy and Physiology II
Popular in Biology
This 12 page Class Notes was uploaded by Gail Chernomorets on Sunday September 18, 2016. The Class Notes belongs to BIOL 224 at University of Nevada - Las Vegas taught by Sean Neiswenter in Fall 2016. Since its upload, it has received 64 views. For similar materials see Human Anatomy and Physiology II in Biology at University of Nevada - Las Vegas.
Reviews for Ch 18 cont'd, Ch 19 Blood
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 09/18/16
9/13 & 9/15 Notes Chapter 18 cont’d The Adrenal Medulla • Response to sympathetic stimulation Adrenal Glands Epinephrine & Norepinephrine • Skeletal muscle and the liver store their own energy • Skeletal muscle burn lipids at rest • In the lungs, inhibitory affect on smooth muscle The Pancreas • Integral in digestion • Endocrine - secrete into bloodstream • Exocrine - secrete into ducts Exocrine Pancreas • Consists of clusters of gland cells called pancreatic acini and their attached ducts - digestive system • Take up 99% of pancreatic volume Endocrine Pancreas • Small % in hormone secretion • Consists of cells that form clusters - known as pancreatic islets • islets of Langerhans 1. Alpha cells • Produce glucagon - response to low blood sugar - increase blood sugar levels 2. Beta cells • Produce insulin - antagonists - response to high blood sugar levels - decrease blood sugar levels 3. Delta cells and F cells • Produce hormones that influence digestive system function **Not a main focus Insulin • A peptide hormone released by beta cells • Effects of insulin on target cells - nutrient uptake - nutrient utilization • ** Functions - accelerates glucose uptake - accelerates glucose utilization and enhances ATP production →burn it - stimulates glycogen formation →store it →skeletal muscle and liver - stimulates amino acid absorption and protein synthesis - stimulates triglyceride formation in adipose tissue →lipids broken down Glucagon • Released by alpha cells • Encourages mobilization of energy • Effects of glucagon on target cells - mobilizes energy reserves • Functions - stimulates break down of glycogen in skeletal muscle and liver cells →stores - stimulates breakdown of triglycerides in adipose tissue - stimulates production of glucose in liver →gluconeogenesis - sugar; new; creation of →“creating new sugar” - producing glucose molecules ** Possible Essay Question Figure 18-17 • Relationship explaining glucose blood levels - negative feedback →antagonistic relationship 1. Normal blood glucose levels (Homeostasis) 2. Rising blood glucose levels (Homeostasis disturbed) • Process to restore Homeostasis - Beta cells secrete insulin - Increased rate of glucose transport into target cells - Increased rate of glucose utilization and ATP generation - Increased conversion of glucose to glycagon - Increased amino acid absorption and protein synthesis - Increased triglyceride synthesis in adipose tissue 3. Blood glucose levels decreases (Homeostasis restored) • Process to restore Homeostasis 1. Falling blood glucose levels (Homeostasis disturbed) - Alpha cells secrete glucagon - Increased breakdown of glycogen to glucose - Increases breakdown of fat to fatty acids - Increased synthesis and release of glucose 2. Blood glucose levels increase (Homeostasis restored) Diabetes Mellitus • Sweet “honey” • Sugars present in urine - large amount of sweet urine - high blood sugar levels (loss of excess water) • Affects ~26 mil people (~8% population) • Another ~80 mil people have prediabetes 2 Types 1. Type I (insulin dependent) diabetes • Inadequate insulin production by the pancreatic beta cells à continual insulin injections - possibilities →autoimmune disease →faulty cells • 5% - 10% of cases - often develops in childhood →not very common 2. Type 2 (non-insulin dependent) diabetes • Misleading; many need insulin • Not an insulin production problem - stop responding to insulin being produced • Associated with obesity - weight loss through diet and exercise can be an effective treatment • Acquire in lifetime; environmental effect • Reversible condition • Overproduction of insulin à down regulation (to become less sensitive) à solution; diet/exercise Adipose Tissue *Leptin • Facilitates feedback control for appetite - feedback through hypothalamus • Stimulated by eating • Creates a “fullness” sensation - maintaining weight, help you feel full and stop eating • Necessary for normal levels of GnRH and gonadotropin - big role in sex development 1. Thin girls • puberty relatively late - obesity a better explanation →enter puberty much earlier 2. Increasing body fat can improve fertility • If you don’t have a lot of body fat 3. Menstruation stops when body fat is low • Women starving themselves • Very athletic women • Countries with low body fat - the US at 7 yo rd - 3 world countries at 16-17 yo Hormone Interactions • Hormones interact to produce coordinated physiological responses - when a cell receives instructions from two hormones at the same time, four possible outcomes 1. Antagonistic effects • Opposing Ex. glucagon and insulin 2. Synergistic effects • Multiplicative effects - 2x – 4x production than they should - much greater Ex. epinephrine and cortisol 3. Permissive effects • One hormone is necessary for another to produce effect Ex. thyroid hormone with metabolism; involve growth hormone 4. Integrative effects • Hormones produce different and complementary results • Response to low levels and stimulate calcitriol Ex. parathyroid and calcitriol - work for same goals with different mechanisms Hormones Important to Growth • Growth hormone (GH) • Thyroid hormones • Insulin • PTH and calcitriol • Reproductive hormones **work together in different ways to guide development Growth Hormone (GH) In children: • Supports muscular and skeletal development In adults: • Maintains hormonal blood glucose concentrations - early 20’s bone fuse and stop growing →last bones to fuse à mandible and clavicle - causes jaw to stick out and pushes shoulder back • Mobilizes lipid reserves - energy utilization • Gigantism - hypersecretion of GH • Dwarfism - hyposecretion of GH • Acromegaly - over secretion of GH causes soft tissue to grow (brow,chin) - very common Thyroid Hormones • If absent or low levels during fetal development or for first year - causes →Nervous system fails to develop normally →Mental retardation results • If T4 concentrations decline before puberty - normal skeletal development will not continue - after puberty →other issues ** biggest effects are during development • Polar cant cross cell membrane, nonpolar can Hormonal Responses to Stress General Adaptation Syndrome (GAS) • Also called stress response • How body responds to stress-causing factors • Is divided into 3 phases - stress in physiological world →anything that tends to push system away from homeostasis 1. Alarm phase • Initial response • Fight or flight • ~1 hour Ex. secretion of epinephrine 2. Resistance phase • Extends effects of epinephrine • High blood glucose levels maintain • High blood pressure • Longer than an hour Ex. cortisol (aldosterone) 3. Exhaustion phase • Consume muscles and break them down • Leads to organ failure • Collapse of biosystems - will die if no improvement The Effects of Hormones on Behavior • Hormone changes can alter intellectual capabilities, memory, learning, and emotional states Ex. cortisol • Stress causes the inability to remember and learn • Affect behavior when endocrine glands are over-secreting or under-secreting Aging and Hormone Production • Few functional changes - doesn’t really decline with age • Decline in concentration of: - growth hormone - reproductive hormone Chapter 19 – Blood The Cardiovascular System • Consists of: - a pump (the heart) - a conducting system (blood vessels) - a fluid medium (blood) →connective tissue - connects cells throughout the body →transports materials to/from cells (function) Ex. oxygen, carbon dioxide, nutrients, hormones, waste products, immune cells and antibodies • System designed to conduct blood throughout the body • Useless unless has conducting vessels Important Functions of Blood • Transportation of solutes - biggest function (main) • Regulation of pH and ion composition of interstitial fluid - system of vessels, closed (loop) allows blood to access any cell, distance a cell away from a vessel; diffusion back and forth - osmotic balance between tissue and blood • Restriction of fluid losses at injury sites • Defense against toxins and pathogens - carries immune system cells and has mechanisms with dealing with pathogens • Stabilization of body temperature - cool off; move blood to surface of skin (sweat) - warm up; blood vessels constrict and blood pulled away from surface ** Blood is half water (ability to maintain high amount of energy); takes a lot of energy to warm and cool down water Physical Characteristics of Blood • About 5L of body in adult human - 4L in small women - 5L in large adult men • Whole blood can be separated into plasma (liquid) and formed elements (solids, mainly cells) - separated by centrifuge • Plasma = fluid and dissolved solutes - water - dissolved plasma proteins - other solutes • Formed elements - all cells and solids The Composition of Plasma • 50-60% of blood volume - whole blood • >90% of plasma is water - water change causes blood volume to change • Plasma and interstitial fluid exchange across capillary walls - nutrients, waste - direct communication between fluid portion of blood and fluid portion of tissues • Can move across capillary walls - water - ions (Na , Ca , Cl , HCO ) - small solutes (fatty acids, glucose, AA) 4+ - wastes (urea, creatinine, NH ) Plasma Proteins • >10% of plasma is proteins, Main different between plasma and other tissues is proteins - don’t leave blood, stay in bloodstream • Albumins - 60% - most common (white) - transports substances such as fatty acids, thyroid hormones, and steroid hormones →important in transport, big class →how lipids dissolved in water →lipids attach to proteins which are water soluble and can be transported • Globulins - 35% - transport globulins (small molecules): →hormone-binding proteins, metallproteins (essential for making RBC; toxic), lipoproteins, and steroid-binding proteins (function as transport proteins, protein binding) - antibodies →also called immunoglobulins →proteins that play role in immune function • Fibrinogen - 4% - functions during blood clotting ** big role in formation of clot, water-soluble protein, dissolved in plasma, converted to fibrin (not soluble), stick to where blood is leaking out Red Blood Cells • Make up 99.9% of blood’s formed elements - ~45% of blood is RBC • Hemoglobin - red pigment that gives whole blood its color - binds and transports oxygen and carbon dioxide - oxygen carrier, move large amounts of O acr2ss the body →transporter for respiratory gases 3 • RBC count is the number of RBCs in 1 microliter (1mm ) of whole blood - 5 mil or so per microliter - male 4.5-6.3 million - female 4.2-5.5 million • Average adult has 25 trillion RBC’s - ~1/3 of all the cells in the body →most common human cell in body • Hermatocrit - packed cell volume (PCV) →is the percentage of RBCs in centrifuged whole blood - 40-50% normal - <40% anemia - >50% polycythemia →more than supposed to have • Centrifuge - separates the blood into its elements Structures of RBCs • Small and highly specialized discs • Thin in middle and thicker at edge (biconcave) - no nucleus bulging it out - no mechanism for making proteins Lifespan of RBCs • Lack nuclei, mitochondria, and ribosomes • Means no repair and use anaerobic metabolism • Live about 120 days ** not worth memorizing Important Effects of RBC Shape on Function 1. High surface-to-volume ration • Quickly absorbs and releases oxygen • Maximize diffusion - too big, cant diffuse fast enough →when lose more slowly, causes problem **Large surface area; large amount of diffusion **Diffusion has to do with surface area 2. Discs form stacks called rouleaux • Flattened disc stacks • Smooth the flow through narrow blood vessels - efficient, important reaction 3. Discs bend and flex entering small capillaries • 7.8 – μm RBC pass through 4 – μm capillary • Flatten stack flexes and bends through capillaries - ability due to biconcave shape ** only mammals have RBC that have this shape to maximize diffusion Hemoglobin (Hb) • Protein that transports respiratory gases (O &2CO ) 2 • Quaternary structure - includes 4 globular protein subunits →2 alpha and 2 beta subunits - similar in structure, slightly different - each subunit contains one molecule of heme →contains iron in the middle of it - each heme contains one iron ion →oxygen binding →4 irons in hemoglobin →O b2nds to iron and get up to 4 O in2the molecule - iron is binding site • Can also carry CO 2n amino acid chain, but can’t carry both - depends on their concentration Hemoglobin Function • 1 RBC contains ~280 million Hb molecules - > billion molecules of O 2 • Plasma [O ]2influences the amount of O ca2ried by Hb • Increase oxygen in the plasma (lung capillaries) - Hb binds oxygen • Decrease oxygen in the plasma (peripheral tissue capillaries) - environment - metabolically active tissue - Hb releases oxygen • Hb also binds and transports CO 2 - byproduct - O 2to tissue, CO 2to RBC RBC Formation and Turnover • About 1% of circulating RBCs wear out per day - survive about 120 days, recycle whole blood supply • About 3 million new RBCs enter the bloodstream each second - to make up for 3 mil that goes out **Do not memorize Hemoglobin Conversion and Recycling • Macrophages - of liver, spleen, and bone marrow - worn out cells get filtered out by these - big eaters - 3x size of typical cell and consume other cells and debris - fixed; job to identify worn out blood cells and consume - phagocytosis →break down hemoglobin into components - idea is to take out before they die or explode and lose components • Broken down into components - Globular proteins à recycled - Heme à converted & excreted →Color, into number of molecules, converted into other things then secreted - iron à bound to proteins à recycled →not bioavailable, high levels extremely toxic →don’t throw away good nutrients, most metals hard to come by Figure 19-5 ** not effective • Liver stores AA as proteins • AA used for many things • Good source of iron is liver and bone marrow • Red bone marrow or iron is where proteins transported • Bile important in lipid digestion and excretion • Feces à white - early sign of liver failure →bilirubin isn’t secreted and builds up in liver - seen a lot in newborns →because they don’t digest anything →come out a little yellow →normal in newborns - in adults →dangerous, bad →jaundice RBC Production In adults, • Erythropoiesis occurs only in myeloid tissue (red bone marrow) - creation of erythrocytes - stem cells mature to become RBCs →single stem cell • Hemocytoblasts - stem cells in myeloid tissue that divide to produce →precursor cell for the blood and ultimately produce any one of the blood cells - can become →myeloid stem cells à mature into RBCs, some WBCs and platelets →lymphoid stem cells à mature into lymphocytes Myeloid stem cells • Most of your cells Regulation of Erythropoesis • Building red blood cells requires amino acids, iron, vitamins B , B ,12nd6folic acid - need presence of hormone Stimulating Hormones à Erythropoietin (EPO) • Secreted by kidneys - 2 endocrine function stimulate bone marrow • Response to hypoxia - low O 2environments - normal response - negative feedback system • Due to disease or high altitude - hypersecretion →polysystemia - hyposecretion →anemia - concentration of O 2an also affect the production of RBC →high altitude training Blood Carries Oxygen • B12and weight loss - save your money - common diet industry →pointless and has no effect - single cofactor involved in RBC production - involve extremely restrictive calorie intake - seen in pernicious anemia →can not directly absorb in nutrition - intrinsic factors allows to absorb in intestine • Blood doping - different ways - increasing number of blood cells in body, perform longer amount of time or at a higher level - take blood and spin down →take out plasma for the red blood cells, freeze elements for 30 days →replace blood cells in your system - temperature increase number of cells in blood and increase carrying capacity of oxygen - illegal →make blood thicker and difficult to pump - can lead to heart failure • Altitude training - still legal - natural increase of EPO