Human Anatomy and Physiology II - Summary - 2YY3 Final PDF

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Human Anatomy and Physiology Final Breakdown: 30 2 images each lab, 3 questions per image 28 Cardiovascular 14 Respiratory 20 Digestive 9 Endocrine 12 Urinary 17 Reproductive Learning Objectives: The three functional components of the CVS (blood, heart, BV) and how they operate to form a functional ...

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Human Anatomy and Physiology Final Breakdown: 30 - 2 images each lab, 3 questions per image 28 - Cardiovascular 14 - Respiratory 20 - Digestive 9 - Endocrine 12 - Urinary 17 - Reproductive Learning Objectives: - The three functional components of the CVS (blood, heart, BV) and how they operate to form a functional system - Role of the respiratory system in maintaining acid-base balance and overall physiological homeostasis - Neuromuscular control of ventilation as well as the intrinsic/extrinsic factors regulating breathing - The structure and function of the human digestive system in the process of breaking down and absorbing macro- and micro-nutrients - The role that the kidney plays in maintaining blood homeostasis, and the mechanisms involved with the production of concentrated or dilute urine - The major organs and their secretions, of the endocrine system, as well as the general characteristics and effects of the major hormones secreted in the body - Structure and function of the reproductive system, including the process of spermatogenesis - Normal periodic structural/physiological changes that occur to the female reproductive system during the menstrual cycle as influenced by hormonal secretions

2 Mediastinum - Central core of thoracic cavity, includes esophagus/trachea/thymus Introduction to Blood Flow - Superior VC transports deoxygenated blood from peripheral tissue to the RA, RV, pushed out to pulmonary trunk (to lungs), returns to heart via LA, LV, leaves via aorta Heart Chambers - RA  RV  Pulmonary Trunk  Pulmonary Arteries (deoxy blood) - L/R Pulmonary Arteries  Lungs  Pulmonary Veins  LA  LV  Aorta  Aortic Arch - Superior VC = Deoxygenated from head/neck - Inferior VC = Below the heart, also blood from coronary sinus (deoxy from heart) Heart Anatomy - Pericardium (pericardial sac) - Fibrous: Tough, fibrous layer, prevents over distention, connects organ to thoracic cavity and anchors to mediastinum - Serous: Thin, transparent inner layer - Parietal: Lines fibrous outer layer - Visceral: Epicardium, covers heart surface - The parietal and visceral are continuous, have a pericardial cavity between them filled with pericardial fluid Pericardium  Fibrous and Serous Serous  Parietal and Visceral Pericardial Cavity  Between Parietal and Visceral (dissipates heat and friction) Heart Wall - Epicardium: Serous membrane, smooth outer surface of the heart - Myocardium: Cardiac muscle, responsible for heart contractions - Endocardium: Smooth inner surface of heart chambers, continuous layer of the CV - Pectinate Muscles: Muscular ridges in auricles and RA wall - Trabeculae Carnae: Muscular ridges and columns on inside walls of ventricles Coronary Circulation (Arteries) - Aorta - Right Coronary Artery (extends to posterior aspect of heart) o Posterior Interventricular Artery (posterior +inferior heart) o Right Marginal Artery (lateral wall of right ventricle) - Left Coronary Artery (posterior and inferior aspects of heart) o Circumflex Artery (posterior wall) o Left Marginal Artery (lateral wall of left ventricle) o Anterior Interventricular Artery (anterior heart)

3 Coronary Circulation (Veins) - Great Cardiac Vein (drain LS of heart) - Small Cardiac Vein (drain right margin of heart) - Coronary Sinus: Large cavity, merges small/great cardiac veins and smaller veins, empties into right atrium Structure of Heart Valves - Ensure one way flow - Atrioventricular Valves (AV): Leaf like cusps attached to papillary muscles by chordae tendinae (tendons) o RS = Tricuspid, LS = Bicuspid/mitral - Semilunar Valves: Cusps shaped like cusps (when full = close) o RS = Pulmonary, LS = Aortic Function of Heart Valves - Relaxed LV o Takes on large volume o Bicuspid open, aortic closed o LV fills w/ blood from LA o Low tension in chordae tendinae, relaxed papillary muscles and cardiac muscles, LV dilated - Contracted LV o Decrease in volume, increase pressure o Bicuspid closed, aortic open o LV empties o Bicuspid everse into LA causing regurgitation of blood but papillary are tense and prevent backflow o High tension in chordae tendinae, contracted papillary muscles and cardiac muscles, LV contracted Route of Blood Flow - Deoxy enters through RA, goes to RV - Right ventricle  pulmonary trunk - R/L branches of pulmonary arteries  lungs (get oxygenated) - Oxygenated blood goes to LS of heart via pulmonary vein - LA  LV  Aorta  Aortic Arch  Body Overview of the CVS - Function: Transport mechanism for human body, immunity, tissue repair, body temperature o Nutrients: Macro/micro (carbs/fat/protein) o Gases: O2, CO2 (metabolic end products) o Other end products of metabolism (hormones) - Opening of the CVS: Hemorrhage (can be internal or external)

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Components of CVS - Heart: Central pump/energy generator (puts E in blood) o Cardiac Muscle: Energy generator + consumer, 95% mass of heart - Blood Vessels: Vasculature, extensions of cardiac tissue - Blood: Fluid contained within the CVS - Kidneys = Blood cleaners, produce urine Functions of the Blood - Transport of Gases, Nutrients, Waste Products o Oxygen, CO2, metabolic end products o Glucose, AA, FA, vitamins o Urea, uric acid, creatinine, ammonia (potentially toxic) o Bilirubin (toxic byproduct of RBC breakdown) o Lactic Acid - Transport of Processed Molecules o Vitamin D precursor from skin  liver  kidneys - Transport of Regulatory Molecules o Hormones (from endocrine glands to rest of body) - Regulation of pH and Osmosis o Normal pH 7.35 – 7.45 o Accumulation of protons, decreases pH o Intense exercise creates acidic enviro, lactic acid accelerates glycolysis - Maintenance of Body Temperature o Heat transfer from muscle tissue to blood to skin to external enviro (exercise increases chemical reactions in muscle, chemical energy  mechanical and thermal energy) o Heat moves down gradient, muscle cools down by moving heat to blood, blood cools down by giving heat to cool areas (like air) - Protection against foreign substances - Clot formation o Built in mechanism for self repair of damaged tissues (BV) – movement causes lesions in BV Composition of Blood - 8% total body weight - 4-6 L in adults - 55% plasma, buffy coat, 45% formed elements - Plasma = 7% proteins, 91% water, 2% other solutes o Proteins = 58% albumins, 38% globulins, 4% fibrinogen (FA transport) o Other Solutes = Ions, nutrients, waste products, gases, regulatory substances (macro, micro nutrients, O2, CO2) - Formed Elements = 250-400 000 platelets, 5-10 000 WBCs, 4.2-6.2 million RBCs o WBC = 60-70% neutrophils, 20-25% lymphocytes, 3-8% monocytes, 2-4% eosinophils, 0.5-1% basophils (immunity)

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Plasma - Liquid part of blood o Colloid: Contains suspended substances o 91% H20, 9% proteins/ions/nutrients/waste products/gases/regulatory substances - Proteins o Albumins: Most abundant, 58%, osmotic pressure (draws H20 from extracellular space), transports FA, thyroid hormones o Globulins: 38% of plasma proteins, transports lipids, carbohydrates, hormones, ions, antibodies o Fibrinogen: 4% of plasma proteins, blood clotting (form mesh over CVS rupture) Formed Elements - Red Blood Cells (Erythrocytes) o 95% o Biconcave disks, no nucleus/mitochondria, anaerobic, can’t divide or repair o Contain hemoglobin that transports O2 and CO2 o Converts CO2 and H2O  H2CO3 (carbonic acid) which turns to carbonic anhydrase - White Blood Cells (Leukocytes) o 5% o Granulocytes: Large, multilobe nuclei  Neutrophils, eosinophils, basophils o Agranulocytes: Small, non-lobed nuclei - Platelets (Thrombocytes)

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Hematopoiesis/Homopoiesis - Blood cell production - Post Birth: Limited to red bone marrow, lymphatic system - Stem Cells: All formed elements derived from single population ( hemocytoblast) - Proerthyroblasts: RBC - Myeloblasts: Basophils, neutrophils, eosinophils - Lymphoblasts: Lymphocytes - Monoblasts: Monocytes - Megakaryoblasts: Platelets Red Blood Cells - 5.4 million/microliter in men, 4.8 in women - Men have up to 25 trillion at any given time - Components: 1/3 hemoglobin, 2/3 lipids/ATP/Carbonic Anhydrase - Transport Functions: o Oxygen: 98.5% bound to hemoglobin, 1.5% dissolved in plasma o CO2: 23% bound to hemoglobin, 7% dissolved in plasma, 70% as bicarbonate o H+: Generated from carbonic anhydrase reaction Hemoglobin: - Quaternary protein structure (4 components) - 1 O2/heme, 4 O2/hemoglobin - Oxyhemoglobin: Saturated w/ O2 (all four sites full) - Deoxyhemoglobin: No O2 - Carbaminohemoglobin: Has CO2 attached - Hemolytic Anemia: Low blood oxygen bc of low RBC count, this is from RBC rupture, but other causes could be autoimmune/enzyme deficiency/free radical accumulation - We don’t require complete saturation of hemoglobin at rest, keep O2 so we can change increase metabolic rate

Structural Features of BV - Arteries o Elastic, muscular (smooth muscle), arterioles - Capillaries o Site of molecular exchange with tissues, smallest BV, good for diffusion - Veins o Thinner walls than arteries, less elastic, fewer smooth muscle cells o Can’t vasodilate or constrict Pulmonary Circulation

7 - From RV to pulmonary trunk - Pulmonary trunk divides into L/R pulmonary arteries (carrying deoxy) - Two pulmonary veins (carrying oxy blood) leave each lung and enter left atrium Systemic Circulation - Aorta: Largest BV, exits LV and is divided into 3 parts o Ascending Aorta: L/R coronary arteries branch from here o Aortic Arch: Arching posterior and to the left, 3 branches  Brachiocephalic Artery (LS)  Left Common Carotid  Left Subclavian Artery (RS) o Descending Aorta: Inferior part of body o Thoracic Aorta: Portion in thorax o Abdominal Aorta: Inferior to diaphragm, ends as two common Iliac arteries Erythropoiesis - Production of RBCs o 2.5 billion RBC’s degenerated per second o 25 trillion RBCs in circulation o Lifespan of 120 days - Erythropoietin hormone (produced by kidney) stimulates production in red bone marrow o Approx. 4 days to make RBC - Stimulus for hormone is low blood O2 o RBCs carry 98% of O2 therefore are essential o Donation = 8-10% loss of volume o Hypoxic environments can alter (altitudes, 1 mile above sea level) o Dietary needs = Folate (B vitamin), B12, Iron (Vitamin C) Carrying Capacity - More RBCs = greater O2 carrying capacity - Aranesp = Drug used to treat anemia (low RBC) by activating enzymes in bone marrow to make RBCs (boost natural mechanisms) - Anemia can be caused by kidney disease (can’t produce erythropoietin hormone) or by cancer treatment - Making RBCs is controlled by O2, normal O2 = put brakes on RBC production by keeping at homeostatic level, low O2 = no brakes Degeneration of RBCs - Get damaged easily because they squeeze through BV (natural degeneration), can’t repair bc anucleated, so can’t replace damaged proteins o Hemoglobin  heme groups, AA components are recycled - Separation of components are done next o Heme = iron removed and recycled (liver, spleen, marrow)  Heme is a chemical group w/ central ion NOT an AA

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Iron free heme is converted to bilirubin which becomes component of bile (processes dietary lipids) o Globin = protein = recycle AAs Leukocytes (WBC) - Protect against micro-organisms, remove dead cells, debris - Nucleated, can proliferate if necessary - Movements: (WBC move through CVS, go after pathogens if something is wrong) o Ameboid: Pseudopods (extend across membranes, engulf parasites) o Diapedesis: Cells become thin, elongate and move either between or through endothelial cells of capillaries, leaves CVS to go after pathogens/healthy cells o Chemotaxis: Attraction to and movement towards foreign material or damaged cells, accumulation of dead WBC and bacteria = pus  Chemoattractants = Cytokines (attract WBC w/ distress signal) - Endothelial cells = line all of CVS, smallest = capillaries (WBC can migrate between) - Injured/diseased cells release chemoattractants (cytokines = attract WBC, distress signal) Neutrophils - 60 to 70% of WBCs - 10-12 hours in circulation, 1-2 days in tissues - Phagocytize bacteria - Secrete lysozyme (enzymes metabolize bacteria), pro-inflammatory muscle injury Eosinophils - 2 to 4% of WBCs - Active in allergic reactions - Destroy inflammatory chemicals like histamine, reduces inflammation - Release chemicals that help destroy tapeworms, flukes, pinworms, hookworms Basophils - 0.5 to 1% of WBCs - Inflammation and allergic response of tissues - Produce histamine (vasodilation and bronchial constriction- increase dilation of BV, increase blood flow, and decrease air flow bc of bronchial constriction) - Produces herapin- factors that form deactivates blood clotting Lymphocytes - 20 to 25% of WBCs - Produced in red bone marrow, proliferates in lymphatic tissue - Produces antibodies (proteins that destroy bacteria, cells containing viruses, tumor cells) Monocytes - 3 to 8% of WBCs - Connect w/ CV, involved in regulating fat in CVS  fat can take over monocyte and cause fat deposits - Become macrophages after 3 days

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Phagocytic cells (ingest bacteria, dead cells, cell fragments) Increases with chronic infection (associated w/ atherosclerotic plaque) WBC increase, metabolic rate increase

Platelets (Thrombocytes) - Cell fragments pinched off from megakaryocytes in red bone marrow - Surface glycoproteins and proteins allow adhesion to other molecules (e.g. collagen) - Important in preventing blood loss... Platelet plugs (accumulation of platelets at blood vessel ‘breaks’), promoting formation and contraction of clots o Will release chemicals to recruit additional platelets to site o Platelets stick together, helpful unless clot breaks off and blocks flow to brain/heart Functions of the Heart - Generating BP o Transfer of energy (contraction to blood movement)  Pressure = force/surface atria  Force is generated through actin/myosin interaction  SA depends on blood vessel diameter (internal SA of CV greater force over smaller area = greater pressure) - Routing blood: 3 circulations (pulmonary = lungs for oxygenation and deposition of CO2, systemic = everything but lungs, coronary = heart) - Ensuring one way blood flow (vales prevent backflow) - Regulating blood supply (likes path of least resistance)  Changes in contraction rate and force match blood delivery to changing metabolic needs  Example: Riding a bike (blood flow to legs increase, blood flow to internal organs decrease) - Physiology affects pressure by constricting/dilating smooth muscle lining of BV o 5L of blood in an adult, fixed amount of blood so flow needs to be sacrificed/changed in order to deal with metabolic needs Histology - Elongated, branching cells containing 1-2 centrally located nuclei - Contain actin/myosin - Intercalated Disks: Specialized cell-cell contacts in cardiac muscle o Cell membrane communicate o Held by desmosomes o Gap junctions allow actin potentials to move from one cell to the next, made of discs, have pore to allow electrical communication Electromechanics - The heart is an electromechanical organ o Actin/myosin bond, use ATP, split it up, transfer that to movement so blood moves o Mechanical event is intracellular, electrical signal is confined to membrane - Mechanical: Cardiac cells contract, produce force (generate mechanical energy, puts into blood to move it), and generates mechanical energy (causes blood to move), decreasing chamber volume

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Electrical: Signals (action potentials) causing the cells to contract Electromechanical Delay: The time between the onset of an electrical stimulus (action potentials) and the onset of the mechanical response (force production), 30-40 milliseconds

Action Potentials - Na/Ca not meant to be in the cell unless something is changing - Channel = gate that opens when activated (made of proteins) - Depolarization is the first step, repolarization resets electrical state but things still aren’t right - Na/K pump: 3 Na out, 2 K in  acts as bouncer, cost 1 ATP every time 3 Na out, 2 K in - Action potentials propogate inside the T tubule of the cell iClickers - Albumin, globulins, and fibrinogen are examples of plasma proteins - Erythrocytes are biconcave disks - The form of hemoglobin that has carbon dioxide attached is called carbaminohemoglobin - Neutrophils are phagocytic, have a trilobed nucleus, and make up the largest percentage of leukocytes

Systemic Circulation: Veins - Return deoxygenated blood and metabolic waste from body to the RA - Major veins: o Coronary sinus (heart) o Superior Vena Cava (head, neck, thorax, upper limbs) o Inferior Vena Cava (abdomen, pelvis, lower limbs) - Types of veins: o Superficial, deep (blood from deep tissues), sinuses (numerous small veins, cranial cavity and heart)

Conducting System - Electrical Pathway o SA Node: Cardiac nodal cells (rhythmical AP, pacemaker), top of RA, action potentials spread to atria (atrial side) o AV Node: Nodal cells, small time delay, slow conduction (nodal cells = slow, they coordinate, so don’t send out super fast), cluster of cells, electrically activated and spread activation throughout ventricles o AV Bundle: Extensions into interventricular septum, have fibers o R+L Bundle Branches: Faster conduction to apex of heart o Purkinje Fibers: Fastest conduction, no need to coordinate because things were already coordinated - 90% of cardiac cells are for contraction (force producing), intercalated disks allow electricity to transfer from one cell to another - AV = ventricle side, picks up SA signal and sends out (causes the time delay)

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Skeletal Muscle Action Potential - Resting State = -85 mV (high extracellular Na, intracellular K+), more negative inside - Depolarization: Na+ influx (Na channels open, K+ channels start opening) - Repolarization: K+ efflux (Na channels closed, K+ open) - Na/K ATPase pump restores ion gradient - Pump acts during resting condition because cells are always having Na leak in - APs are confined to membrane of the cell, contraction = cytoplasm of cell - As quickly as Na channels open, they close Cardiac Muscle Action Potential - 90% of cardiac cells (contractile) - Resting state = -85 mV (high extracellular Na/Ca, intracellular K+) - Depolarization: Na+ influx (Na open, K+ closed, Ca++ start to open) - Early repolarization: Ca++ influx (Na closed, Ca++ open, K+ start opening) - Ca induced Ca release: keep Ca at elevated state which keeps calcium open – Sarcoplasmic reticulum channels are open so the Ca can bind to troponin) - Late repolarization: K+ efflux (K+ channels open) - Na/K ATPase pump restores ion gradient - Plateau occurs ~1.5 seconds because maintaining of Ca release from SR, allowing actin/myosin to come together Autorhythmicity: SA Node AP (Nodal Cells) - Do not rely on force production, more electrical - Autorhythmicity = self generating AP in regular time intervals - Pacemaker potential: Na+ leakage into cells, causes resisting membrane potential to move towards threshold, inside of cell becomes positive, K+ channels closing - Depolarization: Ca+ channels open, K closed - Repolarization: Ca+ close, K open - Sodium leaks in, opens Ca channels (Na decays AP until threshold), E difference causes Ca to open so goes -60 mV to just over 0 mV, potassium will enter cell - Absolute refractory = not generate AP because ions aren’t back - Relative refractory = needs stronger input Autorhythmicity: SA Node AP - Bathing heart in potassium = end life, as long as heart beating, must feed metabolic demands (O2 and nutrients), bathe in K+ and put on ice to slow metabolic activity until transplant can occur - Orange line = AP that is shorter in duration of SA node  functions implicitly to start another AP sooner, increase HR

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Refractory period mV -60 1

Time (ms)

300

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Red line = Slow K+ channel closing, K+ stays in extracellular space longer, keeps cells hyperpolarized, decrease in HR Black line = Fast K+ channel closing, K+ removed from extracellular space sooner, increase in HR

Electrocardiogram - Electrical activity of heart tissue - P Wave: Atrial depolarization (Electrical), Atria relaxed (Mechanical) - QRS Complex: Ventricular depolarization, atrial repolarization (elec), atria contra...