A&PII exam 2 - Study guide for exam 2, Dr. Cummings, Spring 2017 - Human Anatomy & Physiology II PDF

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Study guide for exam 2, Dr. Cummings, Spring 2017...

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Anatomy & Physiology II Exam 2 Objectives

Blood List the functions of blood.  Delivers oxygen o Richness  need  Transports metabolic wastes o CO2  Maintains body temperature o High to low transfer  Maintains body pH o Bicarbonate buffer o 7.35-7.45  Maintains fluid volume  Prevents blood loss o Clotting  Prevents infection o WBCs, antibody transport DOES NOT regulate nutrient levels Describe the composition of whole blood. Derived from the mesoderm Formed Elements – produced in red bone marrow; 46% total  Erythrocytes – carry respiratory gases o 45% of blood volume o Present in the greatest concentration  Leukocytes – 5 different types, all nucleated  Platelets – cell fragments, clotting o Leukocytes + platelets = 1% of blood volume Plasma – 55%  Majority of whole blood by volume  90% water  Solutes o Proteins – albumin (liver), globulins (immune function), gamma globulins = antibodies o Nutrients o Electrolytes o *albumin is a protein found in the plasma, not a formed element in whole blood

Describe the structure, function and production of erythrocytes.  5 mil RBCs/mL blood (5000mL blood in body)  Small  Biconcave  Anucleate – don’t have a nucleus  eliminated for room for more hemoglobin o NO DNA  Hemoglobin – 250million per RBC  Antioxidant enzymes that break down free radicals (peroxisomes)  Men have more RBCs than women o 4.8-5.2 mil/mL for women  lox oxygen  tired o 5.1-5.8 mil/mL for men  too much iron  heart disease o Bone density, menstrual cycle  Hematopoiesis – general blood cell production o About an ounce per day o Composition depends on the needs of the body o Hematopoiesis, leucopoiesis o The hematopoietic stem cell (hemocytoblast) is the stem cell for ALL blood-formed elements  Erythropoiesis – red blood cell production o Stimulus: lack of oxygen o 2 million per second o Occurs in bone marrow

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Hemocytoblast (pluripotent) produces myeloid stem cell (pluripotent) Myeloid stem cell  proerythroblast (can only become RBS; specialized) Proerythroblast  early erythroblast Early erythroblast  late erythroblast Late erythroblast  normoblast Normoblast loses organelles and nucleus to become reticulocyte - Accumulate hemoglobin 7. Reticulocytes (young, anucleuate erythrocyte) mature in blood stream to become erythrocytes - Matures away from the bone marrow - Blood reticulocyte counts provide information regarding?  rate of erythrocyte formation o Regulation

Erythropoietin – when blood becomes hypoxic (reduced availability of oxygen), kidneys start to produce erythropoietin, targets red bone marrow  Testosterone  why men have more RBCs than women; stimulate kidneys  B12, folic acid  Dietary nutrients o Longevity  100-120 days  Old destroyed by macrophages  Heme is split from globin  iron bound to proteins and stored  bilirubin is produced  picked up by the liver  secreted as bile into intestine  pigment degraded and expelled in feces; globin broken down into amino acids - Erythropoitetin causes an increase in release of erythrocytes, which, unless regulated, can induce polycythemia. EPO increases the hematocrit and the red cell mass and can lead to increased viscocity of the blood and an increased tendency to form clots. 

Describe the chemical make-up of hemoglobin.  Globin protein boud to heme pigment  4 polypeptide chains (quaternary structure) o 2 alpha subunits, 2 beta subunits o Will bind 4 oxygen molecules total, 1 per subunit  Heme o Contains iron, which binds oxygen o 1 billion oxygen per RBC  Carbaminohemoglobin o Found with CO2 o Will only carry about 20% of the CO2 in the body, rest is transported via plasma as bicarbonate o CO2 binds to the globin protein  Which part of the hemoglobin molecule binds carbon dioxide for transport?  amino acids of the globin Define: diapedesis - WBCs leaving the blood vessels List the classes, structural characteristics and functions of leukocytes. Complete cells with nuclei and organelles Positive chemotaxis – chemical attraction; attracted to foreign things  Granulocytes – have vesicles that contain things within the cell (granules); derived from myelocytes o Neutrophils

 Most numerous  50-70% of WBCs  Lobed nuclei  Phagocytic, inflammatory response o Eosinophils  Two lobe nucleus  2-4% of WBCs  Attack parasitic worms in body  release enzymes from granules o Basophils  Least common  .1-1% of WBCs  Histamine – vasodilator; attracts other WBCs  Inflammation In a cancer patient undergoing chemotherapy, the decision to utilize a CSF capable of specifically stimulating the production of ONLY the GRANULAR leukocytes would require that the CSF acts exclusively on?  MYELOBLASTS With a patient administered injection of colony stimulating factor (CSF) you would expect to see?  increase white blood cell count  Agranulocytes – no granules o Lymphocytes  Nucleus makes up most of the cell  Reside in lymphatic tissue  Function in immunity  B produce antibodies, T attack own body cells  Develop from lymphoid stem cells o Monocytes  Largest  3-8% of WBCs  Monocyte in vessels, macrophage when it leaves vessels  Phagocytosis

Describe leukopoiesis. Hemocytoblasts give rise to myeloid stem cells and lymphoid stem cells (depending on the stimulus)  parent cell for all formed elements of blood Granulocyte leukopoiesis 1. Myeloid stem cells  myeloblasts 2. Myelosblasts accumulate lysosomes (granules) to become promyelocytes 3. Promyelocytes  myelocytes 4. Cell division stops and nuclei arch to form band cells 5. Nuclei constrict and segment to become mature granulocytes - Half a day to 90 day lifespan, 60% of WBCs Agranulocyte leucopoiesis Monocytes: 1. Myeloid stem cells  monoblasts 2. Monoblasts  promonocytes 3. Promonocytes leave bone marrow and become monocytes in lymph tissue - Can last months Lymphocytes: 1. Lymphoid stem cells  lymphoblasts 2. Lymphoblasts  prolymphocytes 3. Prolymphocytes leave bone marrow and become lymphocytes in lymph tissue - Can last weeks to decades - Only lymphocytes use a stem cell other than myeloid stem cells Regulated by accumulation interleukins and colony-stimulating factors (stimulates) Describe the structure, function and formation of platelets.  Should be in the buddy coat layer when blood is centrifuged.  Anucleated cytoplasmic fragments of megakaryocytes  Granules  clotting chemicals  main function is to promote blood clotting  Thrombopoiesis o Stimulus = thrombopoietin 1. Hemocytoblasts give rise to myeloid stem cells 2. Myeloid stem cells become megakaryoblasts (first specialized cell in process) 3. Megakaryoblasts undergo repeated mitosis but no cytokinesis to form megakaryocytes 4. Cytoplasmic extensions of megakaryocytes break off to be platelets Give examples of disorders caused by abnormalities of each of the formed elements.

Leukocytes  Leukemia – cancerous condition  Infectious mononucleosis – virus  Leukopenia – deficiency in WBCs Erythrocytes  Amenias – not enough o Which of the following would provide no benefit to a person suffering anemia?  supplemental bilirubin injection  Polycythemia – too many  sludge  Suppose that an individual injects himself with erythropoietin in order to raise his level of endurance, an act that is usually illegal in competitive sports. Which of the following could result?  polycythemia  Describe the process of hemostasis, differentiating the intrinsic pathway from the extrinsic pathway. Hemostasis = keeping the blood the same, stop bleeding - Vascular spasm: damaged blood vessel constricts - Platelet plug formation: accumulation of platelets at site of damage o Damage to blood vessel exposes underlying collagen fibers  exposure of collagen fibers causes tissue to release a thromboxane A2 (local signaling molecule) and von Willebrane factor  platelets collect and adhere at damage  thrombin activates platelets to breakdown and release chemical contents - Coagulation: blood gels, integrates fibrin  Intrinsic pathway o Series of reactions in which clotting factors are converted to active forms 1. Aggregated platelets release PF3 2. PF3 activates other intermediates  activate factor X 3. Factor X + Calcium + PF3 + Factor V = prothrombin activator 4. Prothrombin activator catalyzes prothrombin  thrombin 5. Thrombin catalyzes polymerization of fibrinogen to fibrin 6. Factor XIII (via thrombin) links fibrin strands together - What protein involved in coagulation provides the activation for the final step in clotting?  thrombin  Extrinsic pathway o Injured cells release tissue factor o Tissue factor interacts with PF3 to allow shortcut to factor X activation - Extrinsic and intrinsic pathways work together; only difference is that the extrinsic pathway is faster than the intrinsic pathway - The immediate response to blood vessel injury is clotting List factors that limit clot formation.

Want platelets to accumulate to site of damage, but not too big of a clot that would block  Intact endothelial cells secrete PGI2 and heparin  prevent accumulation  Vitamin E quinone  Clotting factors carried away from site by circulating blood  Antithrombin III inactivates thrombin  Protein C inhibits intrinsic pathway events  Heparin (from damaged tissues) enhances activity of antithrombin III and inhibits intrinsic pathway events Explain how the processes of retraction and fibrinolysis relate to the natural elimination of a blood clot. 1. Clot retraction  Platelets contain contractile proteins that become active  Platelets contract, pull against fibrin mesh, squeeze out serum to compact clot  Pulls ruptured edges of vessel closer  PDGF stimulates vessel repair  Leaves congealed clot 2. Fibrinolysis – breaks down congealed clot; disposes of bacteria when healing has occurred  Clot produces plasminogen  Plasminogen  Plasmin o Tissue-plasminogen activator (TPA)  Plasmin digests fibrin o What “clot buster” enzyme removes unneeded clots after healing has occurred during fibrinolysis?  plasmin o As healing progresses, the clot retraction process reduces the size of the clot, while plasminogen is activated into plasmin that digests the fibrin in the clot Identify the hemostatic disorders.  Thromboemboylitic disorders = too much blood clotting o Thrombus – blood clot forms and gets large, kept there, prevents circulation; attached clot that won’t break apart o Embolism – whole clot detaches and travels through the bloodstream, will ultimately block a vessel  Bleeding disorders = don’t produce enough clotting o Thrombocytopenia – insufficient amount of thrombocytes, due to pathology  Hemophilia – genetic o One of the 13 clotting factors in intrinsic pathway can’t be produced o Can’t produce a clot Describe the ABO and Rh blood groups.  Agglutinogens – marks on the cell that do not activate the immune system

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Erythroblastosis fetalis – hemolytic disease of the newborn, RhoGAM

The Heart Describe the location and orientation of the heart.

Base = top, apex = bottom

Name the coverings of the heart.

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Fibrous pericardium – protects and anchors the heart; most superficial Serous pericardium o Parietal layer – superficial to visceral layer o Visceral layer – actual outermost layer of the heart o Pericardial cavity

Describe the structure and the function of the three layers of the heart.  Epicardium  Myocardium – wall, muscle layer  Endocardium – lines inside of the heart; innermost layer o Squamous epithelium List the chambers and anatomical landmarks of the heart. Describe the structure and composition of the heart chambers.  Atria – upper chambers

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o Interatrial septum – separates left and right atria  Hole in it before birth (foramen ovale)  Fossa ovalis = remnant of the hole in the atria; forms immediately after birth o Auricles – external extensions of atria  Look like ears  Increase surface area o Pectinate muscles – little muscles that line the wall of atria Ventricles – lower chambers o Left ventricle is thicker than the right  has to pump out to the entire body o Interventricular septum (always intact) o Interventriuclar groove – between two ventricles; houses blood vessels o Trabeculae carnae - rounded or irregular muscular columns which project from the inner surface of the right and left ventricles of the heart o Papillary muscles – contract to keep valve from turning inside out  Associated with anchoring the right and left atrioventricular valves  Contract to tense the right and left atrioventricular valves via the chordae tendinae, just before ventricular systole.  Chordae tendinae – anchor the AV valves against the large pressure changes that occur as the ventriclse contract Coronary sulcus – groove in heart muscle with blood vessels Chamber-related blood vessels o Vena cavae = largest vein of the body  Superior vena cava: blood from the upper part of the body  Inferior vena cava: blood from the lower part of the body  Connects to the right atrium o Coronary sinus: receives blood from the coronary veins  Connects to the right atrium o Pulmonary veins = lungs  left atrium  Right and left from o Pulmonary artery = right ventricle  lungs o Aorta – largest blood vessel in the body, goes to the entire body

Trace the pathway of blood flow through the heart, including the major blood vessels. Venous blood from superior and inferior venae cavae  right atrium Right atrium through  tricuspid valve  right ventricle Right ventricle  pulmonary semilunar valve  pulmonary artery  lungs (gaseous exchange) Lungs  pulmonary veins  left atrium Left atrium  bicuspid (mitral) valve left ventricle Left ventricle  aortic (semilunar) valve  aorta  the body (gaseous exchange) Differentiate the pulmonary and systemic circuits. The only difference between the pulmonary and systemic circuits is in the direction of gaseous exchange

Capillary beds in lungs = blood gets oxygenated Capillary beds in body tissues = blood gets deoxygenated Higher blood pressure on the left side than the right; BP is measured on the left RIGHT side = PULMONARY circuit pump  The right side of the heart pumps oxygen-poor blood to the lungs to be reoxygenated LEFT side = systemic circuit pump  The left side of the hear pumps blood to the body List the major coronary arteries and veins.  Coronary arteries – carry blood to the heart muscles  Anterior interventriucular artery  Circumflex artery  Marginal artery  Posterior interventricular artery  Cardiac veins o Great o Middle o Small o Anterior  Coronary sinus  Anastomoses – connections of blood vessels o Anastomoses among coronary arterial branches provide collateral routes for blood delivery to the heart muscle Identify the name and location of the valves that control the flow of blood through the heart.  Atrioventricular valves o Tricuspid = right side  Three flaps/cusps  Prevents backflow into the right atrium o Bicuspic (mitral) = left side  Two flaps/cusps  Shaped like the pope’s hat  Prevents backflow into the left atrium - Both regulate the empyting of the atria - Blood pressure must be high enough in the atrium - Functions:  Regulate the flow through  Prevent backflow of blood; unidirectional flow of blood  Cordae tendinae – connect valves to the papillary muscles  Semilunar valves o Aortic = left side  Prevents backflow into the left ventricle o Pulmonary = right side  Prevents backflow into the right ventricle

**** allow pressure gradients to be established, because of the asynchronous contractions of the heart Describe the structural and functional properties of cardiac muscle, contrasting it from skeleton muscle.  Striated  Uni-nucleate  Sliding filament mechanism of action  Adjacent cells locked by desmosomes and gap junctions o Intercalated discs o Gap functions are a form of electrical synapse that allow action potentials to spread to connected cells. This property allows the signal to spread efficiently through the heart.  Myofibrils of cardiac muscle tissue vary in diameter and branch extensively

Heart Physiology Name the components of the conduction system of the heart, and trace the conduction pathway. Intrinsic conduction: autorhythmic cells have unstable resting membrane potentials  Leaky membranes  Slightly permeable to ions that will cause action potentials for the heart to beat  If you cut off all nervous connections, it will still beat because it innervates itself  Sinoatrial node – by the coronary sinus as it goes into the atrium, at the very top of the heart o Create action potentials to make a wave of action potentials down to the AV node o Starting point o Adding a chemical that reduces Na+ transport near the sinoatrial (SA) node would have what effect on the heart’s intrinsic conducting system?  the SA node would depolarize less quickly, reducing the heart rate  AV node  bundle of His  bundle branches o Which will cause the ventricles to depolarize from the apex (directional) to the semilunar valves  Purkinje fibers – carry impulses to the papillary muscles, will depolarize before ventricles

Explain how heart rate is maintained and how it can be modified. Include a discussion of vagal tone. Extrinsic innervation alters the intrinsic pathway. Centers in the brain monitor things like blood oxygen levels and blood volume.  Cardioacceleratory center: sympathetic, speeds up

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Cardioinhibitory center: parasympathetic, slows down If the vagal nerves to the heart were cut, the result would be that  the heart rate would increase by about 25 beats per minute

Draw a diagram of a normal ECG, name the waves and intervals, and describe the electrical events associated with each.  P wave = depolarization of the atria  QRS complex = wave of depolarization across the ventricles o Repolarization of atria occurs, but isn’t seen  T wave = repolarization of the ventricle - During exercise, which of the following would occur on an electrocardiogram (ECG) compared to an individual at rest?  the time from one R to the R of the next heartbeat would decrease Identify what causes normal heart sounds and heart murmurs.  “Lub” = AV valves closing  “Dub” = SL valves closing  Murmur – valves aren’t closing correctly Describe the events of the cardiac cycle.  Systole (contraction) and diastole (relaxation) of both atria plus systole and diastole of both ventricles  At what point in the cardiac cycle is pressure in the ventricles the highest (~120 mm Hg in the left ventricle)  ventricular systole Define cardiac output, identify the normal cardiac output, and describe factors that can affect cardiac output. Cardiac output = the amount of blood that leaves the heart per minute; product of stroke volume and heart rate CO = 75bpm x 70 ml/beat = 5250 ml/min Cardiac reserve = amount that you can increase your cardiac output (max – normal) Stroke volume = amount of blood pushed out per beat Factors affecting stroke volume  Stretch of cardiac muscle o Starling Law of the Heart – stretch increases force of contraction o Stretch is caused by the amount of blood coming into the heart  Contraction strength not due to stretch o Contractility of the heart  exercise o Movement of calcium  Arterial pressure o Afterload phenomenon o Preventing blood from leaving ventricles due to high BP in arteries, stroke volume decreases - Increasing end-diastolic volume will increase stroke volume. Increasing endsystolic volume will decrease stroke volume. Factors affecting heart rate

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Sympathetic nervous system activation (norepinephrine, corresponding increase in contractility) - Norepinephrine acts on the heart by causing threshold to be reached more quickly Parasympathetic nervous system activation (acetylcholine) Adrenal medulla production of epinephrine Thyroid production of thyroxin Blood pressure changes (baroreceptors)

List and describe pathologies related to cardiac output.  Tachycardia – chronic abnormally high HR o Resting HR above 100bpm  Bradycardia – abnormally low HR o Below 60bpm (non-athlete)  Congestive heart failure – cause dangerously low...