A&P 2 - Chapter 18

b

32) The pulmonary arteries carry blood to the A) heart. B) lungs. C) brain. D) intestines. E) liver.

d

50) Complications related to arteriosclerosis account for roughly ________ percent of deaths in the United States. A) 30 B) 60 C) 20 D) 50 E) 25

d

51) Arteriosclerosis can lead to A) hypertension. B) stroke. C) coronary artery disease. D) all of the above E) none of the above

b

52) The first heart sound is heard when the A) AV valves open. B) AV valves close. C) semilunar valves close. D) atria contract. E) blood enters the aorta.

b

59) When the left ventricle contracts, the diameter of the ventricular chamber A) increases. B) decreases. C) remains the same.

c

20) Blood returning to the heart from the pulmonary circuit first enters the A) right atrium. B) right ventricle. C) left atrium. D) left ventricle. E) conus arteriosus.

c

23) The cusps (leaflets) of atrioventricular valves attach directly to A) papillary muscles. B) trabeculae carneae. C) chordae tendineae. D) interatrial septa. E) coronary sulci.

a

24) The right ventricle pumps blood to the A) right and left lungs. B) left ventricle. C) left atrium. D) aorta. E) right atrium.

a

70) The heart pumps approximately ________ milliliters of blood each minute. A) 6,000 B) 15,000 C) 20,000 D) 50,000 E) 100,000

a

95) Cardiac output can be increased by all of the following except one. Choose the exception. A) decreasing ejection fraction B) decreasing end-systolic volume C) increasing stroke volume D) increasing ejection fraction E) increasing heart rate

c

63) What occurs at "B" on the graph? A) semilunar valve opens B) semilunar valve closes C) AV valve opens D) end-systolic volume

b

71) Pacemaker cells in the SA node A) have a well-defined resting potential. B) generate action potentials that spread to the myocardium. C) are highly contractile. D) all of the above E) none of the above

b

58) When the left ventricle contracts, the distance from the apex to the base A) increases. B) decreases. C) remains unchanged.

d

7) The earlike extension of the atrium is the A) ventricle. B) coronary sinus. C) coronary sulcus. D) auricle. E) atricle.

c

5) The visceral pericardium is the same as the A) mediastinum. B) parietal pericardium. C) epicardium. D) myocardium. E) endocardium.

e

83) Which of the following would increase heart rate? A) increased sympathetic stimulation of SA node B) decreased parasympathetic stimulation of nodal fibers C) increased levels of norepinephrine and/or epinephrine D) faster depolarization of the pacemaker potential E) all of the above

a

21) The atrioventricular valves permit blood flow A) in one direction only. B) in both directions. C) in many directions. D) in opposite directions on the right and left. E) none of the above

b

22) Blood leaves the right ventricle by passing through the A) aortic valve. B) pulmonary valve. C) mitral valve. D) tricuspid valve. E) bicuspid valve.

d

25) The left ventricle pumps blood to the A) lungs. B) right ventricle. C) right atrium. D) aorta. E) pulmonary circuit.

c

27) Blood flowing into the heart from the venae cavae flows next through the ________ valve. A) mitral B) bicuspid C) tricuspid D) pulmonary semilunar E) aortic semilunar

b

28) As blood leaves the right ventricle it passes through the ________ and then into the pulmonary trunk. A) pulmonary veins B) pulmonary valve C) aorta D) inferior vena cava E) superior vena cava

e

29) The function of the atrium is to A) collect blood. B) pump blood to the lungs. C) pump blood into the systemic circuit. D) pump blood to the ventricle. E) collect blood and pump blood to the ventricle.

c

30) Compared to the right ventricle, the left ventricle has all the following characteristics, except that it A) has a thicker wall. B) is round in cross section. C) pumps a greater volume. D) contracts harder. E) produces about four to six times more pressure when it contracts.

d

43) The pulmonary semilunar valve prevents backward flow into the A) aorta. B) pulmonary trunk. C) pulmonary veins. D) right ventricle. E) left atrium.

e

44) The bicuspid or mitral valve is located A) in the opening of the aorta. B) in the opening of the pulmonary trunk. C) where the venae cavae join the right atrium. D) between the right atrium and right ventricle. E) between the left atrium and left ventricle.

c

45) The ________ valve prevents backward flow into the left atrium. A) semicaval B) semilunar C) bicuspid D) tricuspid E) pulmonic

e

46) Rupture of the papillary muscles in the left ventricle may result in A) mitral regurgitation. B) mitral valve prolapse. C) bicuspid regurgitation. D) bicuspid prolapse. E) all of the above

b

47) When the semilunar valves close, the AV valves then A) close. B) open. C) make the third heart sound. D) all of the above E) none of the above

c

48) If a patient's tricuspid valve was leaking during systole, what would happen? A) regurgitation into the right atrium B) regurgitation into the superior vena cava C) regurgitation into the left atrium D) all of the above E) none of the above

e

49) David suffers from a prolapsed mitral valve. This condition would cause A) increased effort by the right ventricle. B) increased effort by the left ventricle. C) regurgitation. D) increased effort by the right ventricle and regurgitation. E) increased effort by the left ventricle and regurgitation.

b

53) During the isovolumetric contraction phase of ventricular systole, the A) atria are contracting and the ventricles are relaxing. B) atrioventricular valves and semilunar valves are closed. C) blood is ejected into the great vessels. D) all of the above E) none of the above

b

54) The first heart sound ("lubb") A) is associated with atrial systole. B) is associated with closing of the mitral valve. C) is associated with opening of the mitral valve. D) is associated with closing of the aortic valve. E) is associated with opening of the aortic valve.

e

73) If the pacemaker cells in the SA node become more permeable to potassium ions, the A) heart rate will increase. B) heart rate will decrease. C) membrane will depolarize. D) membrane will hyperpolarize. E) both heart rate will decrease and membrane will hyperpolarize.

b

74) If the connection between the SA node and AV node becomes blocked, A) the ventricles will beat faster. B) the ventricles will beat more slowly. C) the ventricular beat will remain unchanged. D) cardiac output will increase. E) all of the above

c

72) The AV node delivers the stimulus to the AV bundle, located within the interventricular septum. A) The first part of the statement is true but the second part is false. B) The first part of the statement is false but the second part is true. C) Both parts of the statement are true. D) Both parts of the statement are false.

e

108) If there is a complete block between the SA node and the AV node, how would the ECG be affected? A) The P-R interval will be shorter. B) The QRS duration will be longer. C) There will be much bigger P waves. D) The ventricles will stop beating. E) The rate of P waves will be faster than the rate of QRS complexes.

a

109) Each of the following changes will result in increased blood flow to a tissue, except A) increased hematocrit. B) increased vessel diameter. C) increased blood pressure. D) decreased peripheral resistance. E) relaxation of precapillary sphincters.

b

110) Total peripheral resistance is related to all of the following, except the A) length of a blood vessel. B) osmolarity of interstitial fluids. C) flow characteristics. D) blood viscosity. E) blood vessel diameter.

c

111) Averaged over a few heartbeats, venous return is ________ cardiac output. A) much higher than B) somewhat higher than C) equal to D) somewhat lower than E) much lower than

e

112) Which of the following affects blood flow through the body? A) blood viscosity B) vessel diameter C) turbulence D) vascular resistance E) all of the above

b

113) The main control of peripheral resistance by the vasomotor centers occurs in the A) artery. B) arteriole. C) capillary. D) venule. E) vein.

d

114) Turbulent blood flow occurs A) when there are irregularities in the vessel wall. B) at high flow rates. C) when there are sudden changes in vessel diameter. D) all of the above E) none of the above

b

115) Which of the following would have the greater effect on vascular resistance? A) doubling the length of a blood vessel B) decreasing the diameter of a blood vessel by ½ C) Neither would be greater.

a

116) In which of the following would the resistance be greater? A) a vessel 10 microns in diameter B) a vessel 1 mm in diameter

d

117) In which of the following would the blood flow be highest? A) a vessel 0.5 cm in diameter and 2 meters long B) a vessel 1.0 cm in diameter and 10 meters long C) a vessel 0.5 cm in diameter and 4 meters long D) a vessel 1.0 cm in diameter and 2 meters long

c

118) Each of the following factors would increase peripheral resistance, except A) increased sympathetic stimulation. B) elevated levels of epinephrine. C) vasodilation. D) irregularities in the vessel walls caused by plaques. E) elevated hematocrit.

a

119) Blood pressure is highest here. A) artery B) arteriole C) capillary D) venule E) vein

c

120) The difference between the systolic and diastolic pressures is called the ________ pressure. A) critical closing B) mean arterial C) pulse D) blood E) circulatory

b

121) As blood travels from arteries to veins, A) pressure builds. B) pressure drops. C) flow becomes turbulent. D) viscosity increases. E) diameter of the blood vessels gets progressively smaller.

a

122) If blood pressure doubled, the blood flow through a vessel would be A) doubled. B) halved. C) four times greater. D) 1/4 as much. E) unchanged.

e

123) Blood pressure is lowest in the A) arteries. B) arterioles. C) capillaries. D) venules. E) veins.

b

124) If a person has a blood pressure of 120/90, his mean arterial pressure would be ________ mm Hg. A) 210 B) 100 C) 93 D) 105 E) none of the above

e

125) Exchange between a blood vessel and the cells that surround it can occur only in A) arteries. B) arterioles. C) veins. D) venules. E) capillaries.

d

126) Materials can move across capillary walls by A) diffusion. B) filtration. C) reabsorption. D) all of the above E) none of the above

d

127) The blood colloid osmotic pressure mostly depends on the A) concentration of plasma sodium ions. B) concentration of plasma glucose. C) concentration of plasma waste products. D) concentration of plasma proteins. E) number of red blood cells.

e

128) Which of the following statements is false concerning the movement of fluid between capillaries and interstitial space? A) Blood hydrostatic pressure forces fluid from the capillary to the interstitial space. B) Blood osmotic pressure moves fluid from the interstitial space to the capillary. C) The osmotic pressure of the interstitial fluid is less than the blood osmotic pressure. D) The hydrostatic pressure of the interstitial fluid is largely unimportant in determining fluid movement. E) The net filtration pressure is usually zero.

b

129) The vascular pressure that declines from roughly 35 mm Hg to about 18 mm Hg is the A) venous pressure. B) capillary hydrostatic pressure. C) diastolic pressure. D) peripheral pressure. E) pulse pressure.

d

130) Blood flow to a tissue will increase if the A) level of oxygen at the tissue increases. B) level of carbon dioxide at the tissue decreases. C) veins constrict. D) arterioles dilate. E) all of the above

d

131) Which of the following factors will increase the net filtration pressure to move fluid out of capillaries? A) decreased plasma albumen B) increased blood hydrostatic pressure C) decreased tissue hydrostatic pressure D) all of the above E) none of the above

e

132) The continual movement of fluid through the interstitial spaces produced by capillary filtration serves which of the following functions? A) accelerates the distribution of nutrients and hormones B) assists the transport of insoluble substances that cannot enter the capillaries C) helps carry toxins and bacteria to cells of the immune system D) flushes hormones and wastes from the interstitial spaces E) all of the above

d

133) Edema is favored when A) the plasma concentration of protein is reduced. B) endothelial permeability goes up. C) capillary hydrostatic pressure is elevated. D) all of the above E) none of the above

c

134) Stimulation of the aortic baroreceptors results in A) stimulation of the cardioacceleratory center in the brain. B) increased sympathetic stimulation of the heart. C) increased activity by the parasympathetic nervous system. D) stimulation of the vasoconstrictive center. E) increased heart rate.

d

135) Blood pressure increases with all of the following, except increased A) cardiac output. B) peripheral resistance. C) blood volume. D) parasympathetic innervation. E) force of cardiac contraction.

b

136) When will the blood pressure be greater? A) when the peripheral vessels dilate B) when the peripheral vessels constrict

d

137) An increase in the rate of action potentials from baroreceptors will lead to A) increase in heart rate. B) decrease in heart rate. C) decrease in blood pressure. D) both decrease in heart rate and decrease in blood pressure. E) both increase in heart rate and decrease in blood pressure.

b

138) When renin is released from the kidney A) angiotensin II is converted to angiotensin I. B) angiotensin I is activated. C) angiotensin I increases salt reabsorption at the kidneys. D) blood pressure goes down. E) blood flow to the kidneys decreases.

d

139) Each of the following will cause an increase in blood pressure, except A) increased levels of aldosterone. B) increased levels of angiotensin II. C) increased blood volume. D) increased levels of ANP (atrial natriuretic peptide). E) increased levels of ADH (antidiuretic hormone).

b

140) The hormone that produces cardiovascular effects similar to activation of the sympathetic nervous system is: A) acetylcholine. B) epinephrine. C) bradykinin. D) tachykinin. E) sympathetic neuropeptide.

a

141) Each of the following will lead to a decrease in blood pressure, except A) release of renin. B) decrease in blood volume. C) decreased peripheral resistance. D) increased levels of ANP (atrial natriuretic peptide). E) reduced thirst.

e

142) Which of the following are characteristics of cardiovascular regulation? A) Blood flow through tissues meets the demand for oxygen. B) Blood flow changes to match tissue responses. C) Changes occur without drastically altering blood pressure. D) Blood flow through tissues meets the demand for nutrients. E) all of the above

d

143) Increased levels of carbon dioxide in the blood will result in decreased A) heart rate. B) cardiac output. C) blood flow to the lungs. D) parasympathetic stimulation of the heart. E) none of the above

b

144) In comparing a trained athlete to a non-athlete, which of these comparisons is false? A) The athlete has a lower resting heart rate. B) Both hearts weigh about the same. C) The athlete has a higher resting stroke volume. D) The athlete has a higher exercise stroke volume. E) The athlete has a higher exercise cardiac output.

a

145) Which of the following would you expect to have the lowest resting heart rate? A) a trained athlete B) an unconditioned adult C) a person with heart failure D) a teenager with a sedentary lifestyle E) an 80-year-old woman

d

146) During exercise A) vasodilation occurs at the active skeletal muscles. B) venous return increases. C) both cardiac output and stroke volume increase. D) all of the above E) none of the above

c

147) Which of the following changes doesn't occur during exercise compared to rest? A) Cardiac output is higher. B) Heart blood flow is higher. C) Skin blood flow is lower. D) Abdominal viscera blood flow is lower. E) Kidney blood flow is lower.

d

148) In response to hemorrhage, there is A) peripheral vasoconstriction. B) increased sympathetic stimulation of the heart. C) mobilization of the venous reserve. D) all of the above E) none of the above

b

149) Venoconstriction ________ the amount of blood within the venous system, which ________ the volume in the arterial and capillary systems. A) doubles; decreases B) reduces; increases C) decreases; doubles D) increases; reduces E) none of the above

d

26) The right atrium receives blood from the A) coronary sinus. B) superior vena cava. C) inferior vena cava. D) all of the above E) none of the above

b

67) The normal pacemaker of the heart is located in the A) Purkinje fibers. B) sinoatrial node. C) atrioventricular node. D) wall of the left ventricle. E) both the left and right ventricles.

d

68) The following are structural components of the conducting system of the heart. 1. Purkinje fibers 2. AV bundle 3. AV node 4. SA node 5. bundle branches The sequence in which excitation would move through this system is A) 1, 4, 3, 2, 5. B) 3, 2, 4, 5, 1. C) 3, 5, 4, 2, 1. D) 4, 3, 2, 5, 1. E) 4, 2, 3, 5, 1.

c

69) The volume of blood ejected from each ventricle during a contraction is called the A) end-diastolic volume. B) end-systolic volume. C) stroke volume. D) cardiac output. E) cardiac reserve.

d

10) The interventricular sulci and coronary sulcus contain A) fat. B) arteries. C) veins. D) all of the above E) none of the above

c

100) The P wave of the electrocardiogram is a signal from A) depolarization of the SA node. B) depolarization of the AV node. C) depolarization of the atria. D) repolarization of the atria. E) depolarization of the ventricles.

d

101) Depolarization of the ventricles is represented on an electrocardiogram by the A) P wave. B) T wave. C) S wave. D) QRS complex. E) PR complex.

d

102) The T wave on an ECG tracing represents A) atrial depolarization. B) atrial repolarization. C) ventricular depolarization. D) ventricular repolarization. E) ventricular contraction.

e

103) Analysis of the electrocardiogram can reveal all of the following, except the A) heart rate. B) stroke volume. C) condition of the conducting system. D) effects of drugs and poisons. E) duration of the ventricular action potential.

e

104) During the cardiac cycle, the A) P wave of the ECG occurs between the first and second heart sounds. B) QRS complex of the ECG precedes the increase in ventricular pressure. C) second heart sound occurs during atrial systole. D) first heart sound coincides with the QRS complex of the ECG. E) both QRS complex of the ECG precedes the increase in ventricular pressure and first heart sound coincides with the QRS complex of the ECG.

e

105) During the T wave of the electrocardiogram, the ventricles are A) depolarizing. B) repolarizing. C) contracting. D) relaxing. E) both repolarizing and relaxing.

a

106) Depolarization of the atria corresponds to the ECG's A) P wave. B) QRS complex. C) QT interval. D) T wave. E) S-T segment.

c

107) Abnormally slow depolarization of the ventricles would most change the shape of the ________ in an ECG tracing. A) P wave B) T wave C) QRS complex D) P-R interval E) R-T interval

c

31) The following is a list of vessels and structures that are associated with the heart. 1. right atrium 2. left atrium 3. right ventricle 4. left ventricle 5. venae cavae 6. aorta 7. pulmonary trunk 8. pulmonary veins What is the correct order for the flow of blood entering from the systemic circulation? A) 1, 2, 7, 8, 3, 4, 6, 5 B) 1, 7, 3, 8, 2, 4, 6, 5 C) 5, 1, 3, 7, 8, 2, 4, 6 D) 5, 3, 1, 7, 8, 4, 2, 6 E) 5, 1, 3, 8, 7, 2, 4, 6

a

33) The pulmonary veins carry blood to the A) heart. B) lungs. C) brain. D) intestines. E) liver.

b

34) Identify the structure labeled "19." A) tricuspid valve B) pulmonary semilunar valve C) aortic semilunar valve D) bicuspid valve E) ligamentum arteriosum

c

35) Identify the structure labeled "8." A) moderator band B) pectinate muscles C) papillary muscles D) trabeculae carneae E) chordae tendineae

a

36) Identify the structure labeled "6." A) cusp of tricuspid valve B) pulmonary semilunar valve C) aortic semilunar valve D) bicuspid valve E) ligamentum arteriosum

d

37) Identify the structure labeled "21." A) bicuspid valve B) pulmonary semilunar valve C) aortic semilunar valve D) ligamentum arteriosum E) tricuspid valve

c

38) Which chamber receives oxygenated blood from the pulmonary circuit? A) 5 B) 10 C) 16 D) 13 E) both 5 and 16

b

39) The foramen ovale in the fetal heart is located in the A) right atrium. B) left atrium. C) right ventricle. D) left ventricle. E) interatrial septum.

c

4) In the middle of the thoracic cavity is a region occupied by the heart, great vessels, thymus, esophagus, and trachea called the A) pleural space. B) pericardial space. C) mediastinum. D) cardiac notch. E) ventral cavity.

d

40) The wall of the left ventricle is thicker than the right because A) the left ventricle does more work than the right ventricle. B) the left ventricle pumps against greater resistance than the right ventricle. C) the left ventricle produces a higher pressure than the right. D) all of the above E) none of the above

a

41) The ________ ventricle has a greater workload than the ________. A) left; right ventricle B) right; left ventricle C) right; systemic circulation D) all of the above E) none of the above

d

42) Contractions of the papillary muscles A) close the atrioventricular valves. B) close the semilunar valves. C) eject blood from the ventricles. D) prevent the atrioventricular valves from reversing into the atria. E) eject blood from the atria into the ventricles.

d

55) The phase in the cardiac cycle when the mitral valve is closed and the aortic valve is open is the A) atrial systole. B) early diastolic filling phase. C) late diastolic filling phase. D) ventricular ejection of ventricular systole. E) dicrotic phase.

a

56) Which of the following is greater during left ventricular systole? A) the peak pressure in the ventricle B) the peak pressure in the aorta C) Neither is greater.

d

57) The mitral valve closes A) when left ventricular pressure exceeds left atrial pressure. B) at the beginning of ventricular systole. C) at the same time at the tricuspid valve. D) all of the above E) none of the above

a

6) The term used to describe fluid collecting in the pericardial cavity that restricts the movement of the heart is known as A) cardiac tamponade. B) mitral valve prolapse. C) pleural effusion. D) cardiomyopathy. E) pericarditis.

e

60) ________ is to contraction as ________ is to relaxation. A) Systole; diastole B) Diastole; systole C) Filling; relaxing D) Ejection; filling E) Systole; diastole or Ejection; filling

c

61) During ventricular systole, the A) atria are contracting. B) blood is entering the ventricles. C) AV valves are closed. D) pressure in the ventricles remains constant. E) pressure in the aorta remains constant.

d

62) What occurs at the area labeled "D" on the graph? A) AV valve opens B) semilunar valve opens C) diastolic refilling begins D) both AV valve opens and diastolic refilling begins E) both semilunar valve opens and diastolic refilling begins

a

64) What occurs at "A" on the graph? A) semilunar valve opens B) semilunar valve closes C) AV valve opens D) AV valve closes E) end-systolic volume

c

65) What occurs at the circled label "4" on the graph? A) peak systolic pressure B) isovolumetric systole C) isovolumetric contraction D) ventricular refilling E) increased heart rate

a

66) What occurs at the circled label "5" on the graph? A) peak systolic pressure B) isovolumetric systole C) isovolumetric contraction D) ventricular refilling E) increased heart rate

a

75) In cardiac muscle, the fast depolarization phase of the action potential is the result of A) increased membrane permeability to sodium ions. B) increased membrane permeability to potassium ions. C) decreased membrane permeability to calcium ions. D) decreased membrane permeability to sodium ions. E) increased membrane permeability to chloride ions.

b

76) The long plateau phase of the cardiac muscle action potential is due to A) movement of fewer sodium ions across the cell membrane into the cell. B) calcium channels remaining open. C) increased membrane permeability to potassium ion. D) decrease in the amount of calcium diffusing across the membrane. E) increased membrane permeability to sodium ions.

d

77) In cardiac muscle A) calcium ions are not released from the sarcoplasmic reticulum. B) calcium ions do not bind to troponin molecules. C) calcium ions play no role in the process of contraction. D) calcium ions enter the cell through slow ion channels. E) calcium ions play an important role in repolarizing the membrane after the depolarization phase.

c

78) Tetanic muscle contractions don't occur in a normal cardiac muscle because A) cardiac muscle tissue contracts on its own. B) neural stimulation is lacking. C) the refractory period lasts until the muscle relaxes. D) the refractory period ends before the muscle reaches peak tension. E) potassium channels outnumber sodium channels.

c

79) As a result of the long refractory period in the cardiac action potential, cardiac muscle cannot exhibit A) tonus. B) treppe. C) tetany. D) recruitment. E) fatigue.

c

80) Pacemaker cells isolated from the SA node generate action potentials at ________ beats per minute. A) 20-40 B) 40-60 C) 80-100 D) 100-140 E) 140-180

c

81) The heart is innervated by ________ nerves. A) parasympathetic B) sympathetic C) both parasympathetic and sympathetic D) neither parasympathetic nor sympathetic E) somatomotor

c

82) ________ is to slow heart rate as ________ is to fast heart rate. A) Tachycardia; bradycardia B) Bradycardia; cardiomyopathy C) Bradycardia; tachycardia D) Cardiac tamponade; bradycardia E) none of the above

b

84) Drugs that block the beta-one adrenergic receptors will A) increase heart rate. B) decrease heart rate. C) increase contractility. D) increase cardiac output. E) decrease the end-systolic volume.

c

85) The heart beats approximately ________ times each day. A) 1,000 B) 10,000 C) 100,000 D) 1,000,000 E) 10,000,000

c

86) At a heart rate of 60 beats/minute, a cardiac cycle lasts A) 60 seconds. B) 60 milliseconds. C) 1 second. D) 370 milliseconds. E) 630 milliseconds.

e

87) Acetylcholine slows the heart because it A) opens potassium ion channels in SA node cells. B) opens sodium-calcium ion channels in SA node cells. C) causes the pacemaker potential to depolarize more quickly. D) causes the pacemaker potential to depolarize more slowly. E) opens potassium ion channels in SA node cells and causes the pacemaker potential to depolarize more slowly.

b

88) Activation of which kind of receptor causes heart rate to increase? A) alpha-one receptor B) beta-one receptor C) muscarinic receptor D) beta-two receptor E) preganglionic

c

89) Heart rate is controlled by neurons of the cardiovascular center located in the A) pons. B) thalamus. C) medulla oblongata. D) hypothalamus. E) higher centers.

b

9) There are ________ pulmonary veins. A) 2 B) 4 C) 6 D) 8 E) 10

e

90) The cardioacceleratory center activates sympathetic neurons and the cardioinhibitory center controls parasympathetic neurons. A) The first part of the statement is true but the second part is false. B) The first part of the statement is false but the second part is true. C) Both parts of the statement are true. D) Both parts of the statement are false. E) Both parts of the statement are true and relate to brainstem control of heart rate.

d

91) Stroke volume depends on A) end-diastolic volume. B) the contractility of the ventricle. C) the pressure required to pump blood into the aorta. D) all of the above E) none of the above

a

92) Drugs known as calcium channel blockers such as nifedipine can be used to A) decrease the force of cardiac contraction. B) increase blood pressure. C) increase the rate of cardiac contraction. D) none of the above E) all of the above

b

93) Which of the following would be greater? A) the end-diastolic volume when the heart rate is 150 beats/minute B) the end-diastolic volume when the heart rate is 60 beats/minute

b

94) Each of the following factors will increase cardiac output, except A) increased venous return. B) increased parasympathetic stimulation. C) increased sympathetic stimulation. D) increased heart rate. E) both increased venous return and increased parasympathetic stimulation.

d

96) Cardiac output is increased by A) more sympathetic stimulation. B) increased end-diastolic volume. C) increased stroke volume. D) all of the above E) none of the above

c

97) What effect would compressing the inferior vena cava just below the diaphragm have on cardiac function? A) Stroke volume would increase. B) Cardiac output would increase. C) Sympathetic stimulation of the heart would increase. D) all of the above E) none of the above

d

98) Which of these would cause stroke volume to increase? A) when venous return is increased B) when venous return is decreased C) when diastolic blood pressure is decreased D) both when venous return is increased and when diastolic blood pressure is decreased E) both when venous return is decreased and when diastolic blood pressure is decreased

e

99) If the connection between the vagus nerve and the heart is cut, which of these changes will occur? A) heart will beat slower B) stroke volume will decrease C) cardiac output will decrease D) nodal fibers will depolarize more slowly E) none of the above