Anatomy & Physiology ch 19
Anatomy & Physiology ch 19 Biol 2301
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Human Anatomy & Physiology, 8e (Marieb/Hoehn) Chapter 19 The Cardiovascular System: Blood Vessels Matching Questions Figure 19.1 Using Figure 19.1, match the following: 1) Sinusoid capillary. Answer: C Diff: 1 Page Ref: 699; Fig. 19.3 2) Capillary found in endocrine organs that allows hormones to gain rapid entry into the blood. Answer: B Diff: 2 Page Ref: 699; Fig. 19.3 3) Capillary with intercellular clefts found in the skin and muscles. 1 Copyright © 2010 Pearson Education, Inc. Answer: A Diff: 2 Page Ref: 699; Fig. 19.3 4) Capillary that may contain Kupffer cells in the lining. Answer: C Diff: 2 Page Ref: 699; Fig. 19.3 5) Capillary found where active capillary absorption of filtrate occurs. Answer: B Diff: 2 Page Ref: 699; Fig. 19.3 Figure 19.2 Using Figure 19.2, match the following: 6) Splenic vein. Answer: B Diff: 1 Page Ref: 743; Fig. 19.29 7) Superior mesenteric vein. Answer: E Diff: 1 Page Ref: 743; Fig. 19.29 8) Inferior mesenteric vein. Answer: D Diff: 1 Page Ref: 743; Fig. 19.29 9) Hepatic portal vein. 2 Copyright © 2010 Pearson Education, Inc. Answer: A Diff: 1 Page Ref: 743; Fig. 19.29 3 Copyright © 2010 Pearson Education, Inc. 10) Right gastroepiploic vein. Answer: C Diff: 1 Page Ref: 743; Fig. 19.29 Match the following: A) Common hepatic artery B) Renal artery C) Inferior mesenteric artery D) Internal iliac artery E) Aorta 11) Largest artery of the body. Diff: 1 Page Ref: 724 12) Supplies the kidney. Diff: 1 Page Ref: 732; Tbl. 19.4 13) Supplies the duodenum and stomach. Diff: 2 Page Ref: 731; Tbl. 19.4 14) Supplies the distal areas of the large intestine. Diff: 2 Page Ref: 732; Tbl. 19.4 15) Supplies pelvic structures. Diff: 2 Page Ref: 734; Tbl. 19.4 16) Artery that does not anastomose. Diff: 3 Page Ref: 701 Answers: 11) E 12) B 13) A 14) C 15) D 16) B 4 Copyright © 2010 Pearson Education, Inc. Match the following: A) Internal carotid artery B) Brachiocephalic trunk C) Radial artery D) Celiac trunk E) External iliac artery 17) Gives rise to the right common carotid and right subclavian artery. Diff: 1 Page Ref: 724; Tbl. 19.4 18) Supplies the lower limbs. Diff: 2 Page Ref: 734; Tbl. 19.4 19) Common site to take the pulse. Diff: 2 Page Ref: 711 20) Major supply to the cerebral hemispheres. Diff: 2 Page Ref: 726 21) Large unpaired branch of the abdominal aorta that supplies the liver, stomach, and spleen. Diff: 2 Page Ref: 731 Answers: 17) B 18) E 19) C 20) A 21) D Match the following: A) Subclavian vein B) External jugular vein C) Pulmonary trunk D) Axillary artery E) Superior vena cava 22) Receives blood from all areas superior to the diaphragm, except the heart wall. Diff: 2 Page Ref: 736; Tbl. 19.9 23) Carries oxygenpoor blood to the lungs. Diff: 2 Page Ref: 722 24) Drains the scalp. Diff: 2 Page Ref: 738; Tbl. 19.9 25) Runs through the armpit area, giving off branches to the axillae, chest wall, and shoulder girdle. Diff: 2 Page Ref: 728; Tbl. 19.4 5 Copyright © 2010 Pearson Education, Inc. 6 Copyright © 2010 Pearson Education, Inc. 26) Drains the upper extremities, deep vein. Diff: 2 Page Ref: 736; Tbl. 19.9 Answers: 22) E 23) C 24) B 25) D 26) A Match the following: A) Femoral artery B) Great saphenous vein C) Superior mesenteric artery D) Pulmonary vein E) Brachial artery 27) Artery usually palpated to take the blood pressure. Diff: 1 Page Ref: 728 28) Major artery of the thigh. Diff: 1 Page Ref: 734 29) Supplies the small intestine. Diff: 1 Page Ref: 732 30) Carries oxygenrich blood from the lungs. Diff: 1 Page Ref: 722 31) Vessel commonly used as a coronly bypass vessel. Diff: 2 Page Ref: 744 Answers: 27) E 28) A 29) C 30) D 31) B Match the following: A) Arterioles B) Capillaries C) Large veins D) Large arteries 32) Site where resistance to blood flow is greatest. Diff: 1 Page Ref: 704 33) Site where exchanges of food and gases are made. Diff: 1 Page Ref: 698 34) Site where blood pressure is lowest. Diff: 1 Page Ref: 705706 7 Copyright © 2010 Pearson Education, Inc. 8 Copyright © 2010 Pearson Education, Inc. 35) Site where the velocity of blood flow is fastest. Diff: 2 Page Ref: 713; Fig. 19.14 36) Site where the velocity of blood flow is slowest. Diff: 2 Page Ref: 713; Fig. 19.14 37) Site where the blood volume is greatest. Diff: 2 Page Ref: 701 38) Site where the blood pressure is greatest. Diff: 2 Page Ref: 705 39) Site that is the major determinant of peripheral resistance. Diff: 2 Page Ref: 698 Answers: 32) A 33) B 34) C 35) D 36) B 37) C 38) D 39) A True/False Questions 1) The adjustment of blood flow to each tissue in proportion to its requirements at any point in time is termed autoregulation. Answer: TRUE Diff: 1 Page Ref: 714 2) Arterial pressure in the pulmonary circulation is much higher than in the systemic circulation because of its proximity to the heart. Answer: FALSE Diff: 1 Page Ref: 722723 3) Osmotic pressure is created by the presence in a fluid of small diffusible molecules that easily move through the capillary membrane. Answer: FALSE Diff: 1 Page Ref: 718 4) The cerebral arterial circle (circle of Willis) is an arterial anastomosis. Answer: TRUE Diff: 1 Page Ref: 727 5) The outermost layer of a blood vessel is the tunica intima. Answer: FALSE Diff: 1 Page Ref: 695 6) The thickwalled arteries close to the heart are called muscular arteries. Answer: FALSE Diff: 1 Page Ref: 698 9 Copyright © 2010 Pearson Education, Inc. 10 Copyright © 2010 Pearson Education, Inc. 7) Hypotension is generally considered systolic blood pressure that is below 100 mm Hg. Answer: TRUE Diff: 1 Page Ref: 712 8) A precapillary sphincter is a cuff of smooth muscle that regulates the flow of blood into the capillaries. Answer: TRUE Diff: 1 Page Ref: 700 9) The carotid sinus reflex protects the blood supply to the brain, whereas the aortic reflex is more concerned with maintaining adequate blood pressure in the systemic circuit as a whole. Answer: TRUE Diff: 2 Page Ref: 708 10) Vasodilation is a widening of the lumen due to smooth muscle contraction. Answer: FALSE Diff: 1 Page Ref: 695 11) The pulmonary circulation does not directly serve the metabolic needs of body tissues. Answer: TRUE Diff: 1 Page Ref: 722 12) In infants and young people, congenital vascular problems are less common than congenital heart disease. Answer: TRUE Diff: 1 Page Ref: 745 13) The most common form of shock is hypovolemic shock. Answer: TRUE Diff: 1 Page Ref: 719 14) Every minute, about 1.5 ml of fluid leaks out of the capillaries. Answer: TRUE Diff: 1 Page Ref: 719 15) The pancreas is an example of an organ with arteries that do not anastomose. Answer: FALSE Diff: 1 Page Ref: 701 16) An obstruction in the superior vena cava would decrease the flow of blood from the head and neck to the heart. Answer: TRUE Diff: 2 Page Ref: 736; Tbl. 19.9 17) Arteries supplying the same territory are often merged with one another, forming arterial 11 Copyright © 2010 Pearson Education, Inc. anastomoses. Answer: TRUE Diff: 2 Page Ref: 701 18) An increase in blood viscosity will cause an increase in peripheral resistance. Answer: TRUE Diff: 2 Page Ref: 704 19) The first major branch of the femoral artery is the dorsalis pedis artery. Answer: FALSE Diff: 2 Page Ref: 734 20) The azygos vein originates in the abdomen. Answer: TRUE Diff: 3 Page Ref: 740 21) Whereas diffusion is more important for solute exchange between plasma and interstitial fluid, bulk flow is more important for regulation of the relative volumes of blood and interstitial fluid. Answer: TRUE Diff: 2 Page Ref: 717718 MultipleChoice Questions 1) Which of the following is not one of the three main factors influencing blood pressure? A) cardiac output B) peripheral resistance C) emotional state D) blood volume Answer: C Diff: 2 Page Ref: 706 2) Which of the following chemicals does not help regulate blood pressure? A) ADH B) atrial natriuretic peptide C) angiotensin II D) nitric acid Answer: D Diff: 1 Page Ref: 709 3) Which statement best describes arteries? A) All carry oxygenated blood to the heart. B) All carry blood away from the heart. C) All contain valves to prevent the backflow of blood. D) Only large arteries are lined with endothelium. 12 Copyright © 2010 Pearson Education, Inc. Answer: B Diff: 1 Page Ref: 695 13 Copyright © 2010 Pearson Education, Inc. 4) Which tunic of an artery contains endothelium? A) tunica intima B) tunica media C) tunica externa D) basement membrane Answer: A Diff: 1 Page Ref: 695 5) Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of ________. A) arterioles B) arteries C) veins D) capillaries Answer: D Diff: 1 Page Ref: 698 6) The circulatory route that runs from the digestive tract to the liver is called ________. A) hepatic portal circulation B) pulmonary circulation C) coronary circulation D) cerebral circulation Answer: A Diff: 1 Page Ref: 742 7) The arteries that are also called distributing arteries are the ________. A) elastic arteries B) muscular arteries C) arterioles D) capillaries Answer: B Diff: 1 Page Ref: 698 8) Aldosterone will ________. A) promote an increase in blood pressure B) promote a decrease in blood volume C) result in a larger output of urine D) decrease sodium reabsorption Answer: A Diff: 1 Page Ref: 710 9) The pulse pressure is ________. A) systolic pressure plus diastolic pressure B) systolic pressure minus diastolic pressure C) systolic pressure divided by diastolic pressure 14 Copyright © 2010 Pearson Education, Inc. D) diastolic pressure plus 1/3 (systolic pressure plus diastolic pressure) Answer: B Diff: 1 Page Ref: 705 10) Which of the following signs of hypovolemic shock is a relatively late sign? A) cold, clammy skin B) increased heart rate C) rapid, thready pulse D) rapidly falling blood pressure Answer: D Diff: 2 Page Ref: 719; Fig. 19.18 11) Which of the following is likely during vigorous exercise? A) Blood will be diverted to the digestive organs. B) The skin will be cold and clammy. C) Capillaries of the active muscles will be engorged with blood. D) Blood flow to the kidneys increases. Answer: C Diff: 1 Page Ref: 716 12) Which of the choices below explains why the arterioles are known as resistance vessels? A) Their prime function is the exchange of nutrients and wastes between the blood and tissue cells. B) The contraction and relaxation of the smooth muscle in their walls can change their diameter. C) They distribute blood to various parts of the body. D) They contain a large quantity of elastic tissue. Answer: B Diff: 2 Page Ref: 698 13) Which of the following is true about veins? A) Venous valves are formed from the tunica media. B) Up to 35% of total body blood is in venous circulation at any given time. C) Veins have a small lumen in relation to the thickness of the vessel wall. D) Veins are called capacitance vessels or blood reservoirs. Answer: D Diff: 2 Page Ref: 700701 14) Which of the following processes provides a longterm response to changes in blood pressure? A) neural controls B) baroreceptorinitiated reflexes C) chemoreceptorinitiated reflexes D) renal regulation Answer: D Diff: 1 Page Ref: 710 15 Copyright © 2010 Pearson Education, Inc. 16 Copyright © 2010 Pearson Education, Inc. 15) Peripheral resistance ________. A) decreases with increasing length of the blood vessel B) increases as blood vessel diameter increases C) increases as blood viscosity increases D) is not a major factor in blood pressure in healthy individuals Answer: C Diff: 2 Page Ref: 704 16) Brain blood flow autoregulation ________. A) is less sensitive to pH than to a decreased oxygen level B) causes constriction of cerebral blood vessels in response to a drop in systemic blood pressure C) is abolished when abnormally high CO le2els persist D) is controlled by cardiac centers in the pons Answer: C Diff: 2 Page Ref: 716 17) Blood flow to the skin ________. A) is controlled mainly by decreasing pH B) increases when environmental temperature rises C) increases when body temperature drops so that the skin does not freeze D) is not an important source of nutrients and oxygen for skin cells Answer: B Diff: 1 Page Ref: 716 18) Which of the choices below reflects the balance (or imbalance) between the direction and amount of fluid that flows across the capillary walls? A) hydrostatic and osmotic pressure B) hydrostatic pressure only C) blood volume and viscosity D) plasma and formed element concentration Answer: A Diff: 2 Page Ref: 718 19) Which of the following is a type of circulatory shock? A) hypovolemic, caused by increased blood volume B) cardiogenic, which results from any defect in blood vessels C) vascular, due to extreme vasodilation as a result of loss of vasomotor tone D) circulatory, where blood volume is normal and constant Answer: C Diff: 2 Page Ref: 719720 17 Copyright © 2010 Pearson Education, Inc. 20) Which tunic of an artery is most responsible for maintaining blood pressure and continuous blood circulation? A) tunica intima B) tunica media C) tunica externa D) basement membrane Answer: B Diff: 2 Page Ref: 695 21) The influence of blood vessel diameter on peripheral resistance is ________. A) the only factor that influences resistance B) significant because resistance is inversely proportional to the fourth power of the vessel radius C) significant because resistance is directly proportional to the blood vessel diameter D) insignificant because vessel diameter does not vary Answer: B Diff: 2 Page Ref: 704 22) The form of circulatory shock known as hypovolemic shock is ________. A) the form of shock caused by anaphylaxis B) any condition in which blood vessels are inadequately filled and blood cannot circulate normally C) shock that results from largescale loss of blood volume, or after severe vomiting or diarrhea D) always fatal Answer: C Diff: 1 Page Ref: 719 23) In the dynamics of blood flow through capillaries, hydrostatic pressure ________. A) and osmotic pressure are the same B) is the same as capillary blood pressure C) generally forces fluid from the interstitial space into the capillaries D) is completely canceled out by osmotic pressure Answer: B Diff: 1 Page Ref: 718 24) The hepatic portal vein ________. A) is actually an artery B) carries nutrientrich blood to the liver C) carries oxygenrich blood from the liver to the viscera D) carries blood from the liver to the inferior vena cava Answer: B Diff: 1 Page Ref: 742 18 Copyright © 2010 Pearson Education, Inc. 25) The term ductus venosus refers to ________. A) a fetal shunt that bypasses the lungs B) damage to the valves in the veins, leading to varicose veins C) a condition of the aged in which the arteries lose elasticity D) a special fetal vessel that allows umbilical blood to bypass the liver Answer: D Diff: 1 Page Ref: 745 26) Which of the choices below does not explain why low capillary pressures are desirable? A) Capillaries are fragile and high pressures would rupture them. B) Most capillaries are extremely permeable and thus even low pressures force solutecontaining fluid out of the bloodstream. C) Low blood pressure is more desirable than high blood pressure. Answer: C Diff: 2 Page Ref: 705 27) Which of the choices below does not involve tissue perfusion? A) delivery of oxygen and nutrients to, and removal of wastes from, tissue cells B) gas exchange in the lungs C) absorption of nutrients from the digestive tract D) blood clotting Answer: D Diff: 1 Page Ref: 713714 28) Which of the following do not influence arterial pulse rate? A) activity B) postural changes C) emotions D) the vessel selected to palpate Answer: D Diff: 2 Page Ref: 711 29) Which of the following are involved directly in pulmonary circulation? A) superior vena cava, right atrium, and left ventricle B) right ventricle, pulmonary artery, and left atrium C) left ventricle, aorta, and inferior vena cava D) right atrium, aorta, and left ventricle Answer: B Diff: 2 Page Ref: 722723 19 Copyright © 2010 Pearson Education, Inc. 30) Histologically, the ________ is squamous epithelium supported by a sparse connective tissue layer. A) tunica intima B) tunica media C) tunica externa D) tunica adventitia Answer: A Diff: 2 Page Ref: 695 31) The arteries that directly feed into the capillary beds are called ________. A) muscular arteries B) elastic arteries C) arterioles D) venules Answer: C Diff: 2 Page Ref: 698 32) Fenestrated capillaries ________. A) are not more permeable than continuous capillaries B) are not common in endocrine organs and in areas where capillary absorption is an important function C) do not occur in the glomerular capillaries of the kidneys D) are not found in the brain Answer: D Diff: 2 Page Ref: 699 33) Modified capillaries that are lined with phagocytes are called ________. A) sinuses B) sinusoids C) thoroughfare channels D) anastomoses Answer: B Diff: 2 Page Ref: 699 34) Factors that aid venous return include all except ________. A) activity of skeletal muscles B) pressure changes in the thorax C) venous valves D) urinary output Answer: D Diff: 2 Page Ref: 705706 20 Copyright © 2010 Pearson Education, Inc. 35) Which of the following blood pressure readings would be indicative of hypertension? A) 120/80 in a 30yearold man B) 140/90 in a 70yearold woman C) 170/96 in a 50yearold man D) 110/60 in a 20yearold woman Answer: C Diff: 2 Page Ref: 712 36) Select the correct statement about factors that influence blood pressure. A) An increase in cardiac output corresponds to a decrease in blood pressure, due to the increased delivery. B) Systemic vasodilation would increase blood pressure, due to diversion of blood to essential areas. C) Excess protein production would decrease blood pressure. D) Excess red cell production would cause a blood pressure increase. Answer: D Diff: 2 Page Ref: 703704 37) Mechanisms that do not help regulate blood pressure include ________. A) nervous control that operates via reflex arcs involving baroreceptors, chemoreceptors, and higher brain centers B) the dural sinus reflex C) renal regulation via the reninangiotensin system of vasoconstriction D) chemical controls such as atrial natriuretic peptide Answer: B Diff: 2 Page Ref: 708710 38) The velocity of blood flow is ________. A) in direct proportion to the total crosssectional area of the blood vessels B) slower in the arteries than in capillaries because arteries possess a relatively large diameter C) slower in the veins than in the capillaries because veins have a large diameter D) slowest in the capillaries because the total crosssectional area is the greatest Answer: D Diff: 2 Page Ref: 713714 39) Select the correct statement about blood flow. A) It is relatively constant through all body organs. B) It is measured in mm Hg. C) It is greatest where resistance is highest. D) Blood flow through the entire vascular system is equivalent to cardiac output. Answer: D Diff: 2 Page Ref: 703 21 Copyright © 2010 Pearson Education, Inc. 40) A thrombus (blood clot) in the first branch of the arch of the aorta would affect the flow of blood to the ________. A) left side of the head and neck B) myocardium of the heart C) left upper arm D) right side of the head and neck and right upper arm Answer: D Diff: 3 Page Ref: 724; Tbl. 19.4 41) Cerebral blood flow is regulated by ________. A) skin temperature B) ADH C) intrinsic autoregulatory mechanisms D) the hypothalamic "thermostat" Answer: C Diff: 3 Page Ref: 716 42) A patient with essential hypertension might have pressures of 200/120 mm Hg. This hypertensive state could result in all of the following changes except ________. A) increased work of the left ventricle B) increased incidence of coronary artery disease C) increased damage to blood vessel endothelium D) decreased size of the heart muscle Answer: D Diff: 3 Page Ref: 713 43) The shortterm controls of blood pressure, mediated by the nervous system and bloodborne chemicals, primarily operate via all but which of the following? A) reflex arcs involving baroreceptors B) altering blood volume C) reflex arcs associated with vasomotor fibers D) chemoreceptors Answer: B Diff: 1 Page Ref: 706709 44) Secondary hypertension can be caused by ________. A) obesity B) stress C) arteriosclerosis D) smoking Answer: C Diff: 1 Page Ref: 713 22 Copyright © 2010 Pearson Education, Inc. 45) Where in the body would you find low oxygen levels causing vasoconstriction and high levels causing vasodilation? A) kidney B) lungs C) liver D) heart Answer: B Diff: 2 Page Ref: 717 46) Normal average blood pressure for a newborn baby is ________. A) 120/80 B) 90/55 C) 150/90 D) 130/80 Answer: B Diff: 2 Page Ref: 745 47) If blood pressure is almost normal in a person who has lost blood, does that mean the tissues are receiving adequate blood flow? A) yes B) no C) not necessarily Answer: C Diff: 3 Page Ref: 719 48) What do the ductus arteriosus and the foramen ovale become at birth? A) ligamentum teres; fossa ovalis B) fossa ovalis; ligamentum arteriosum C) ligamentum arteriosum; ligamentum teres D) ligamentum arteriosum; fossa ovalis Answer: D Diff: 3 Page Ref: 745 49) Which of the following would not result in the dilation of the feeder arterioles and opening of the precapillary sphincters in systemic capillary beds? A) a decrease in local tissue oxygen content B) an increase in local tissue carbon dioxide C) a local increase in histamine D) a local increase in pH Answer: C Diff: 2 Page Ref: 706710 23 Copyright © 2010 Pearson Education, Inc. 50) Arteriole blood pressure increases in response to all but which of the following? A) increasing stroke volume B) increasing heart rate C) rising blood volume D) falling blood volume E) all of these Answer: D Diff: 2 Page Ref: 705 51) The baroreceptors in the carotid sinus and aortic arch are sensitive to which of the following? A) a decrease in carbon dioxide B) changes in arterial pressure C) a decrease in oxygen levels D) an increase in oxygen levels Answer: B Diff: 1 Page Ref: 707708 FillintheBlank/Short Answer Questions 1) The first major branch of the aortic arch is the ________ branch. Answer: brachiocephalic trunk Diff: 1 Page Ref: 724; Tbl. 19.4 2) The embryonic mesodermal cells that will eventually form the endothelial lining of blood vessels are called ________. Answer: blood islands Diff: 2 Page Ref: 745 3) The most common form of shock is ________. Answer: hypovolemic Diff: 1 Page Ref: 719 4) A family of peptides called ________ are released by the endothelium and are among the most potent vasoconstrictors known. Answer: endothelins Diff: 2 Page Ref: 714 5) Arterial ________ provide alternate pathways for blood to get to an organ. Answer: anastomoses Diff: 1 Page Ref: 701 6) The ________ in the carotid sinuses and aortic arch detect increases in blood pressure. Answer: baroreceptors Diff: 1 Page Ref: 707708 24 Copyright © 2010 Pearson Education, Inc. 7) ________ shock is due to abnormal expansion of blood vessels and a rapid drop in blood pressure. Answer: Vascular Diff: 1 Page Ref: 719720 8) The third major branch of the aortic arch is the ________ artery. Answer: left subclavian Diff: 1 Page Ref: 724; Tbl. 19.4 9) The ________ supply the brain with blood. Answer: internal carotid arteries Diff: 1 Page Ref: 724; Tbl. 19.4 10) ________ pressure is the difference between systolic and diastolic pressure. Answer: Pulse Diff: 1 Page Ref: 705 11) The lowest venous blood pressure is found in the ________. Answer: venae cavae Diff: 2 Page Ref: 705706 12) As a blood pressure cuff is deflated on the arm, sounds of ________ can be heard. Answer: Korotkoff Diff: 2 Page Ref: 711712 13) Which type of blood vessels contain valves and what is their function? Answer: Veins contain valves to prevent blood from flowing backward. This is necessary because the venous vessels are a lowpressure system and the blood must sometimes flow against gravity, particularly in the limbs. Diff: 2 Page Ref: 700701 14) Describe the forces that determine fluid movements across capillary walls. Answer: (1) Capillary hydrostatic pressure (equal to capillary blood pressure) tends to force fluid out of capillaries into the interstitial spaces. (2) Osmotic pressure, created by large nondiffusible particles in the blood, tends to draw water into the capillaries. At the arterial end of the capillary bed, hydrostatic forces dominate and fluid moves out, while at the venous end, osmotic forces dominate and the net fluid movement is into the capillaries. Diff: 3 Page Ref: 717719 15) Define vasoconstriction and vasodilation. What is the mechanism of regulation? Answer: Vasoconstriction is a reduction in the lumen diameter of a blood vessel due to smooth muscle contraction. Vasodilation is a widening of the lumen due to smooth muscle relaxation. Both are regulated by vasomotor nerve fibers of the sympathetic division of the autonomic nervous system. Diff: 2 Page Ref: 695 25 Copyright © 2010 Pearson Education, Inc. 26 Copyright © 2010 Pearson Education, Inc. 16) Consider the diameter of one 4mm blood vessel and two 2mm blood vessels. Would the two 2mm vessels carry more, less, or the same amount of fluid, given that pressure is a constant? Why? Answer: The two 2mm vessels would deliver considerably less fluid for two reasons: (1) the resistance in the smaller vessels is much greater and (2) the volume of the 4mm vessel is greater than that of two 2mm vessels. Draw a 4inch circle; then put two 2inch circles in it and notice the volume difference. Diff: 3 Page Ref: 704 17) Based on what we have learned about the regulation of blood flow to various organs, do you think it is wiser to rest or exercise after a heavy meal? Explain your answer. Answer: At rest, the abdominal organs receive approximately 24% of the total blood flow. With exercise, blood flow is shifted away from abdominal organs to skeletal muscles. It would therefore be wiser to rest after a heavy meal to allow optimum function of the organs of digestion and absorption of nutrients. Diff: 3 Page Ref: 716 18) The abdominal aorta divides into three arteries at its terminus; what are they? Answer: Left and right common iliac arteries and the median sacral artery. Diff: 2 Page Ref: 730; Tbl. 19.7 19) The mesenteric arteries branch off the abdominal aorta, but the mesenteric veins do not connect directly to the vena cava. Why? Answer: The mesenteric veins merge into the hepatic portal vein before entering the liver. The liver dumps into the vena cava. Diff: 2 Page Ref: 742 27 Copyright © 2010 Pearson Education, Inc. Clinical Questions 1) Describe the effect of hypovolemic shock on the blood vessels and the heart. Answer: Hypovolemic shock causes blood vessels to constrict to increase venous return and maintain pressure. Heart rate increases to compensate for loss of blood pressure and to maintain cardiac output. If volume loss continues, pressure eventually drops sharply and the shock becomes irreversible, leading to death. Diff: 3 Page Ref: 719 2) Atherosclerosis is a progressive disease of blood vessels that is responsible for millions of deaths each year. Describe the disease process, noting the involvement of specific cell/tissue types and molecules. Answer: The disease process involves several stages and usually affects the aorta and coronary arteries. The initial event involves damage to the tunica intima caused by bloodborne chemicals or physical factors such as a blow or infection. Injured endothelial cells release chemicals that increase the uptake by the endothelium of fats, LDLs, and cholesterol. This eventually attracts macrophages that ingest the oxidized fats and, along with smooth muscle cells from the tunica media, transform into foam cells. Foam cells become fatty streaks, which, along with collagen and elastin fibers secreted by smooth muscle cells, form atherosclerotic plaques. These protrude into the lumen and narrow the blood vessels. Diff: 3 Page Ref: 702 3) A woman in her early 50s appeared at a walkin clinic, complaining of aching pain in her right leg following a fall. Visual examination revealed that the medial aspect of that leg was red and swollen. A diagnosis of phlebitis was made. What is phlebitis, and what more serious condition may result if proper healing does not occur? Answer: Phlebitis is an inflammation of a vein accompanied by painful throbbing and redness of the skin over the inflamed vessel. Thrombophlebitis (clot formation) can result if proper healing does not occur. The danger in thrombophlebitis is the possibility that a clot could detach and form an embolus. Diff: 3 Page Ref: 748 4) For each of the following situations, describe the anticipated effect on blood pressure and the physiological basis of the response: (1) a highsalt diet, (2) a blow on the head that damages (disables) the vasomotor center, (3) an attack by a mugger, and (4) a hypothalamic tumor resulting in excess ADH production. Answer: (1) A highsalt diet causes increased sodium in the blood, which increases total extracellular fluid volume. This leads to increased blood volume and blood pressure. (2) Damage to the vasomotor center will cause a loss of vasomotor tone and a drop in blood pressure because the vasomotor center is the integrating center for blood pressure control. (3) During the mugger attack, blood pressure would increase due to sympathetic nervous system stimulation (the fight orflight response) triggered by the hypothalamus. (4) Excess ADH production would cause an increase in blood pressure through increased water retention and therefore increased blood volume. ADH also stimulates vasoconstriction. Diff: 3 Page Ref: 706710 28 Copyright © 2010 Pearson Education, Inc. 29 Copyright © 2010 Pearson Education, Inc. 5) Mrs. Gray, a 50yearold mother of seven children, is complaining of dull, aching pains in her legs. She reports that they have been getting progressively worse since the birth of her last child. During her physical examination, numerous varicosities are seen in both legs. How are varicosities recognized? What veins are most likely involved? What pathologic changes have occurred in these veins, and what is the most likely cause in this patient's case? Answer: Varicosities are recognized by the enlargement of the veins. Superficial veins are most likely involved because they have little support from surrounding tissues. The veins have become tortuous and dilated because of incompetent valves that allow the blood to pool, stretching the vein walls. The likely cause in this patient's case is her pregnancies, because the enlarged uterus exerts downward pressure on groin vessels, restricting return blood flow to the heart. Diff: 3 Page Ref: 701 6) Mr. Wilson is a 45yearold stockbroker with essential hypertension. He is African American, obese, and he smokes 23 packs of cigarettes daily. What risk factors for hypertension are typified by Mr. Wilson? What steps should be taken to treat Mr. Wilson, and what lifestyle changes should he make? What complications are likely if corrective steps are not taken? Answer: The risk factors are obesity, race, a highstress job, and smoking. Mr. Wilson should lose weight, reduce salt intake, quit smoking, and try to reduce his stress level, perhaps by relaxation training. Medical intervention could include treatment with diuretics, beta blockers, calcium channel blockers, and angiotensin converting enzyme inhibitors. Complications could include atherosclerosis, heart failure, renal failure, and stroke. Diff: 3 Page Ref: 713 7) A pregnant patient comes into a clinic and asks about a small dark bulge that is becoming more apparent on her leg. What is it and what caused it? Answer: The patient is getting a varicose vein. Due to the growing fetus putting downward pressure on the vessels of the groin and restricting the return of blood to the heart, the valves in the peripheral veins begin to fail. This causes blood pooling, which enlarges these veins and puts additional strain on other peripheral vein valves down the line. Diff: 3 Page Ref: 701 8) At the battle of Shiloh in the American Civil War, Confederate General A. S. Johnston was killed when he was shot in the thigh. Witnesses reported that he bled to death almost before he realized that he was wounded. Which blood vessel was most likely to have been injured? Why is a tourniquet usually ineffective in stopping the bleeding from this wound? Answer: The wound severed his femoral artery, the largest artery serving the lower limb. A tourniquet may be ineffective because it is a highpressure, deep artery with a large diameter. It is therefore difficult to exert enough pressure through the thigh muscles to stop the bleeding. Diff: 3 Page Ref: 734 30 Copyright © 2010 Pearson Education, Inc. 9) A patient lost a lot of blood during surgery and his blood pressure dropped from 120/80 to 90/50. Describe how the kidneys respond to this change in blood pressure. Answer: When arterial blood pressure declines, special cells in the kidneys release the enzyme renin into the blood. Renin triggers a series of enzymatic reactions that produce angiotensin II, which is a potent vasoconstrictor. Angiotensin causes an increase in systemic blood pressure, and increases the rate of blood delivery to the kidneys and renal perfusion. It also stimulates the adrenal cortex to secrete aldosterone, a hormone that enhances renal reabsorption of sodium, and prods the posterior pituitary to release ADH, which promotes more water reabsorption. As sodium moves into the bloodstream, water follows; thus both blood volume and blood pressure rise. Diff: 3 Page Ref: 710 10) A patient has an 80% blockage of his left anterior descending coronary artery. Describe what occurs in terms of myocardial oxygen supply and demand if his sympathetic nervous system is stimulated. Answer: When the sympathetic nervous system is stimulated there is increased myocardial contractility, which increases cardiac output and blood flow to active muscles. This increases the demand for oxygen to the cells. The coronary artery is a major blood vessel of the heart. When the demand for myocardial oxygen exceeds the ability of the coronary arteries to supply it, death of myocardial tissue can occur. Diff: 3 Page Ref: 724; Tbl. 19.4 31 Copyright © 2010 Pearson Education, Inc.
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