Physiology Chapter 19

1) Which of the following is not true regarding fenestrated capillaries? A) Fenestrated capillaries in endocrine organs allow hormones rapid entry into the blood. B) Fenestrated capillaries in the small intestine receive nutrients from digested food. C) Fenestrated capillaries are essential for filtration of blood plasma in the kidney. D) Fenestrated capillaries form the blood-brain barrier.

2) 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) decreased size of the heart muscle B) increased incidence of coronary artery disease C) increased damage to blood vessel endothelium D) increased work of the left ventricle

3) What do the ductus arteriosus and the foramen ovale become at birth? A) fossa ovalis; ligamentum arteriosum B) ligamentum arteriosum; ligamentum teres C) ligamentum arteriosum; fossa ovalis D) ligamentum teres; fossa ovalis

4) Which tunic of an artery is most responsible for maintaining blood pressure and continuous blood circulation? A) tunica intima B) tunica externa C) tunica media D) tunica adventitia

5) Which of the following processes provides a long-term response to changes in blood pressure? A) neural controls B) renal regulation C) chemoreceptor-initiated reflexes D) baroreceptor-initiated reflexes

6) Which of the following is the most significant source of blood flow resistance? A) blood vessel diameter B) blood viscosity C) blood vessels type D) total blood vessel length

7) A thrombus (blood clot) in the first branch of the arch of the aorta would affect the flow of blood to the ________. A) myocardium of the heart B) right side of the head and neck and right upper arm C) left upper arm D) left side of the head and neck

8) Which of the choices below explains why the arterioles are known as resistance vessels? A) They distribute blood to various parts of the body. B) Their prime function is the exchange of nutrients and wastes between the blood and tissue cells. C) They contain a large quantity of elastic tissue. D) The contraction and relaxation of the smooth muscle in their walls can change their diameter.

9) Which of the choices below does not explain why low capillary pressures are desirable? A) Low capillary pressure reduces the load of drainage the lymphatic drainage must handle B) Most capillaries are extremely permeable and thus even low pressures force solute-containing fluid out of the bloodstream. C) Low blood pressure is associated with longer life span than high blood pressure. D) Capillaries are fragile and high pressures would rupture them.

10) Which of the following signs of hypovolemic shock is a relatively late sign? A) cold, clammy skin B) rapid, thready pulse C) increased heart rate D) rapidly falling blood pressure

11) Factors that aid venous return include all except ________. A) urinary output B) venous valves C) activity of skeletal muscles D) pressure changes in the thorax

12) Which of the following statements regarding the hepatic portal system is false? A) It consists of a vein connecting two capillary beds together. B) It carries nutrients, toxins, and microorganisms to the liver for processing. C) Its major vessels are the superior mesenteric, inferior mesenteric, and splenic veins. D) It branches off of the inferior vena cava.

13) 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) an increase in local tissue carbon dioxide B) a decrease in local tissue oxygen content C) a local increase in histamine D) a local increase in pH

14) The influence of blood vessel diameter on peripheral resistance is ________. A) significant because resistance is directly proportional to the blood vessel diameter B) insignificant because vessel diameter does not vary C) the only factor that influences resistance D) significant because resistance is inversely proportional to the fourth power of the vessel radius

15) Which of the following is likely during vigorous exercise? A) Blood flow to the kidneys increases. B) Blood will be diverted to the digestive organs. C) Capillaries of the active muscles will be engorged with blood. D) The skin will be cold and clammy.

16) Blood flow to the skin ________. A) is controlled mainly by decreasing pH B) is not an important source of nutrients and oxygen for skin cells C) increases when body temperature drops so that the skin does not freeze D) increases when environmental temperature rises

17) Modified capillaries that are lined with phagocytes are called ________. A) sinusoids B) thoroughfare channels C) anastomoses D) fenestrations

18) The baroreceptors in the carotid sinus and aortic arch are sensitive to which of the following? A) changes in arterial pressure B) a decrease in carbon dioxide C) a decrease in oxygen levels D) an increase in oxygen levels

19) Which of the following do not influence arterial pulse rate? A) the vessel selected to palpate B) postural changes C) activity D) emotions

20) Which of the following blood pressure readings would be indicative of hypertension? A) 140/90 in a 70-year-old woman B) 110/60 in a 20-year-old woman C) 120/80 in a 30-year-old man D) 170/96 in a 50-year-old man

21) 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 pressure only B) hydrostatic and osmotic pressure C) plasma and formed element concentration D) blood volume and viscosity

22) Normal average blood pressure for a newborn baby is ________. A) 150/90 B) 130/80 C) 90/55 D) 120/80

23) Which of the following chemicals does not help regulate blood pressure? A) atrial natriuretic peptide B) nitric acid C) ADH D) angiotensin II

24) Cerebral blood flow is regulated by ________. A) ADH B) skin temperature C) intrinsic autoregulatory mechanisms D) the hypothalamic "thermostat"

25) Which statement best describes arteries? A) All carry blood away from the heart. B) All contain valves to prevent the backflow of blood. C) Only large arteries are lined with endothelium. D) All carry oxygenated blood to the heart.

26) Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of ________. A) arterioles B) veins C) arteries D) capillaries

27) Which of the following are involved directly in pulmonary circulation? A) right ventricle, pulmonary artery, and left atrium B) left ventricle, aorta, and inferior vena cava C) superior vena cava, right atrium, and left ventricle D) right atrium, aorta, and left ventricle

28) Brain blood flow autoregulation ________. A) is abolished when abnormally high CO2 levels persist B) is controlled by cardiac centers in the pons C) causes constriction of cerebral blood vessels in response to a drop in systemic blood pressure D) is less sensitive to pH than to a decreased oxygen level

29) Select the correct statement about factors that influence blood pressure. A) Systemic vasodilation would increase blood pressure, due to diversion of blood to essential areas. B) Excess protein production would decrease blood pressure. C) An increase in cardiac output corresponds to a decrease in blood pressure, due to the increased delivery. D) Excess red cell production would cause a blood pressure increase.

30) Arteriolar blood pressure increases in response to all but which of the following? A) falling blood volume B) rising blood volume C) increasing heart rate D) increasing stroke volume E) all of these

31) The term ductus venosus refers to ________. A) a fetal shunt that bypasses the lungs B) a special fetal vessel that allows umbilical blood to bypass the liver C) damage to the valves in the veins, leading to varicose veins D) a condition of the aged in which the arteries lose elasticity

32) Which of the following is a type of circulatory shock? A) vascular, due to extreme vasodilation as a result of loss of vasomotor tone B) cardiogenic, which results from any defect in blood vessels C) circulatory, where blood volume is normal and constant D) hypovolemic, caused by increased blood volume

33) Select the correct statement about blood flow. A) It is relatively constant through all body organs. B) It is greatest where resistance is highest. C) Blood flow through the entire vascular system is equivalent to cardiac output. D) It is measured in mm Hg.

34) In the dynamics of blood flow through capillaries, hydrostatic pressure ________. A) is the same as capillary blood pressure B) is completely canceled out by osmotic pressure C) and osmotic pressure are the same D) generally forces fluid from the interstitial space into the capillaries

35) The short-term controls of blood pressure, mediated by the nervous system and bloodborne chemicals, primarily operate via all but which of the following? A) reflex arcs associated with vasomotor fibers B) reflex arcs involving baroreceptors C) chemoreceptors D) altering blood volume

36) The pulse pressure is ________. A) systolic pressure divided by diastolic pressure B) systolic pressure plus diastolic pressure C) diastolic pressure plus 1/3 (systolic pressure plus diastolic pressure) D) systolic pressure minus diastolic pressure

37) Aldosterone will ________. A) promote a decrease in blood volume B) promote an increase in blood pressure C) result in a larger output of urine D) decrease sodium reabsorption

38) Peripheral resistance ________. A) decreases with increasing length of the blood vessel B) increases as blood viscosity increases C) increases as blood vessel diameter increases D) is not a major factor in blood pressure in healthy individuals

39) Which of the following is true about veins? A) Veins are called capacitance vessels or blood reservoirs. B) Veins have a small lumen in relation to the thickness of the vessel wall. C) Up to 35% of total body blood is in venous circulation at any given time. D) Venous valves are formed from the tunica media.

40) If blood pressure is almost normal in a person who has lost blood, does that mean the tissues are receiving adequate blood flow? A) no B) not necessarily C) yes

41) The arteries that directly feed into the capillary beds are called ________. A) venules B) arterioles C) elastic arteries D) muscular arteries

42) Histologically, the ________ is squamous epithelium supported by a sparse connective tissue layer. A) tunica adventitia B) tunica intima C) tunica externa D) tunica media

43) The most common type of blood capillary is the ________. A) sinusoidal capillary B) distributing capillary C) continuous capillary D) fenestrated capillary

44) The arteries that are also called distributing arteries are the ________. A) muscular arteries B) arterioles C) elastic arteries D) capillaries

45) Mechanisms that do not help regulate blood pressure include ________. A) the dural sinus reflex B) nervous control that operates via reflex arcs involving baroreceptors, chemoreceptors, and higher brain centers C) chemical controls such as atrial natriuretic peptide D) renal regulation via the renin-angiotensin system of vasoconstriction

46) The velocity of blood flow is ________. A) slower in the veins than in the capillaries because veins have a large diameter B) slowest in the capillaries because the total cross-sectional area is the greatest C) slower in the arteries than in capillaries because arteries possess a relatively large diameter D) in direct proportion to the total cross-sectional area of the blood vessels

47) Secondary hypertension can be caused by ________. A) stress B) arteriosclerosis C) smoking D) obesity

48) Which of the following is not one of the three main factors influencing blood pressure? A) emotional state B) cardiac output C) blood volume D) peripheral resistance

49) The form of circulatory shock known as hypovolemic shock is ________. A) any condition in which blood vessels are inadequately filled and blood cannot circulate normally B) always fatal C) shock that results from large-scale loss of blood volume, or after severe vomiting or diarrhea D) the form of shock caused by anaphylaxis

50) Where in the body would you find low oxygen levels causing vasoconstriction and high levels causing vasodilation? A) lungs B) heart C) kidney D) liver

51) Which of the choices below does not involve tissue perfusion? A) blood clotting B) absorption of nutrients from the digestive tract C) gas exchange in the lungs D) delivery of oxygen and nutrients to, and removal of wastes from, tissue cells