CHAPTER 20
93) 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.
A
100) 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
49) 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
53) Which of the following descriptions matches the term near the left fifth intercostal space? A) pericardial cavity B) visceral pericardium C) apex of heart D) aorta E) right atrium
C
16) 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.
E
23) 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.
E
13) 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
C
2) 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
86) 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
54) 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.
A
58) 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) both A and D
A
65) The ________ ventricle has a greater workload than the ________. A) left; right ventricle B) right; left ventricle C) right; systemic circulation D) both A and C E) none of the above
A
74) Depolarization of the atria corresponds to the EKG s A) P wave. B) QRS complex. C) QT interval. D) T wave. E) S-T segment.
A
76) The structure that permits blood flow from the right atrium to the left atrium in the fetal circulation is the A) foramen ovale. B) interatrial septum. C) coronary sinus. D) fossa ovalis. E) ligamentum arteriosus.
A
78) Excess fluid in the ________ causes cardiac tamponade. A) pericardial cavity B) visceral pericardium C) apex of heart D) left ventricle E) both atria
A
82) 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
A
9) Most of the middle layer in the heart wall is composed of A) cardiac myocytes. B) chondrocytes. C) epitheliocytes. D) fibrocytes. E) smooth muscle cells.
A
92) AV nodal cells are poorly interconnected compared to contractile cells but they have bigger diameters. 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.
A
34) 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.
D
56) Intercalated discs serve to transfer ________ from cell to cell. A) ionic currents B) action potentials C) the force of contraction D) all of the above E) A and B only
D
7) 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
94) 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
E
96) Cardiac output is increased by A) more sympathetic stimulation. B) increased end systolic volume. C) increased stroke volume. D) all of the above E) A and C only
E
98) 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) A and C only
E
1) Blood returning to the heart from the systemic circuit first enters the A) right atrium. B) right ventricle. C) left atrium. D) left ventricle. E) conus arteriosus.
A
22) The pulmonary veins carry blood to the A) heart. B) lungs. C) brain. D) intestines. E) liver.
A
26) The marginal branch and posterior interventricular branch are branches of the A) right coronary artery. B) left coronary artery. C) circumflex artery. D) coronary sinus. E) aorta.
A
30) 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.
A
48) Artery is to ________ as vein is to ________. A) efferent; afferent B) afferent; efferent C) toward; away D) afferent; away E) none of the above
A
31) The long plateau phase of the cardiac muscle action potential is due to A) movement of fewer sodium ions across the cell membrane. 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.
B
33) 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.
B
38) 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.
B
51) The heart is roughly the size of A) a thigh. B) a man s clenched fist. C) the gallbladder. D) the hand of a 10-year-old. E) Texas.
B
85) When the left ventricle contracts, the diameter of the ventricular chamber A) increases. B) decreases. C) remains the same.
B
97) 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
99) 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
B
17) The ________ valve prevents backward flow into the left atrium. A) semicaval B) semilunar C) bicuspid D) tricuspid E) pulmonic
C
11) The left ventricle pumps blood to the A) lungs. B) right ventricle. C) right atrium. D) aorta. E) pulmonary circuit.
D
12) The right atrium receives blood from the A) coronary sinus. B) superior vena cava. C) inferior vena cava. D) A, B, and C E) B and C only
D
15) The pulmonary semilunar valve prevents backward flow into the A) aorta. B) pulmonary trunk. C) pulmonary veins. D) right ventricle. E) left atrium.
D
3) The earlike extension of the atrium is the A) ventricle. B) coronary sinus. C) coronary sulcus. D) auricle. E) atricle.
D
36) 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
70) Pacemaker cells in the SA node A) have a well-defined resting potential. B) show a slow spontaneous depolarization. C) are connected by gap junctions to atrial myocytes. D) both B and C E) both A and C
D
81) Which of these comparisons between skeletal and heart muscle is false? A) both have T-tubules. B) both release calcium ion from the sarcoplasmic reticulum. C) both are striated. D) both rely entirely on oxidative metabolism for energy. E) both trigger contraction by membrane depolarization.
D
91) An increase in the rate of action potentials from baroreceptors will reflexly lead to A) increase in heart rate. B) decrease in heart rate. C) decrease in blood pressure. D) both B and C E) both A and C
D
18) 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) both A and D
E
37) The T wave on an ECG tracing represents A) atrial depolarization. B) atrial repolarization. C) ventricular depolarization. D) ventricular repolarization. E) ventricular contraction.
D
46) 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) systolic ejection phase. E) dicrotic phase.
D
84) When the left ventricle contracts, the distance from the apex to the base A) increases. B) decreases. C) remains unchanged.
B
10) The right ventricle pumps blood to the A) right and left lungs. B) left ventricle. C) left atrium. D) aorta. E) right atrium.
A
4) The coronary sulcus is a groove that A) marks the border between the atria and ventricles. B) marks the boundary line between the right and left ventricles. C) marks the boundary line between the right and left atria. D) separates the atrioventricular valves from the atria. E) separates the coronary arteries from the coronary veins.
A
50) The heart pumps approximately ________ liters of blood each day. A) 8,000 B) 15,000 C) 20,000 D) 50,000 E) 100,000
A
14) As blood leaves the right ventricle it passes through the ________ and then into the pulmonary trunk. A) pulmonary veins B) conus arteriosus C) aorta D) inferior vena cava E) superior vena cava
B
21) The pulmonary arteries carry blood to the A) heart. B) lungs. C) brain. D) intestines. E) liver.
B
32) 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) at least half of the calcium ion required for contraction comes from outside the cell. E) calcium ions play an important role in repolarizing the membrane after the depolarization phase.
D
55) The interventricular sulci and coronary sulcus contain A) fat. B) arteries. C) veins. D) all of the above E) B and C only
D
59) During the T wave of the electrocardiogram, the ventricles are A) depolarizing. B) repolarizing. C) contracting. D) relaxing. E) both B and D
E
25) The first blood vessels to branch from the aorta are the ________ arteries. A) pulmonary B) coronary C) circumflex D) carotid E) subclavian
B
27) The circumflex branch and the anterior interventricular artery are branches of the A) right coronary artery. B) left coronary artery. C) interventricular artery. D) coronary sinus. E) aorta.
B
39) 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
40) During the isovolumetric 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) B and C only
B
43) 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 A and B
B
47) 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.
B
61) There are ________ pulmonary veins. A) 2 B) 4 C) 6 D) 8 E) none of the above
B
63) When the semilunar valves close, the AV valves then A) close. B) open. C) make the third heart sound. D) both B and C E) both A and C
B
69) A heartbeat lasts A) 3 seconds. B) 370 msec. C) 5 seconds. D) 100 msec. E) none of the above
B
71) The first heart sound ( lub ) 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.
B
77) Blood leaves the right ventricle by passing through the A) aortic valve. B) pulmonary valve. C) mitral valve. D) tricuspid valve. E) bicuspid valve.
B
19) 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) works harder. E) produces about six to eight times more pressure when it contracts.
C
20) 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
C
24) Blood is supplied to the myocardium by A) the coronary sinus. B) contact with blood in the pumping chambers. C) the coronary arteries. D) arteries that branch from the pulmonary arteries. E) both A and C
C
28) The great and middle cardiac veins drain blood into the A) superior vena cava. B) inferior vena cava. C) coronary sinus. D) coronary sulcus. E) aorta.
C
29) The heart is innervated by ________ nerves. A) parasympathetic B) sympathetic C) both parasympathetic and sympathetic D) neither parasympathetic nor sympathetic E) somatomotor
C
35) 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.
C
42) 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.
C
44) An increase in end-diastolic volume increases the stroke volume is a way of stating A) Robin s law of the heart. B) Finch s law of the heart. C) Starling s law of the heart. D) Sparrow s law of the heart. E) Hawking s law of the heart.
C
5) 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.
C
6) The cusps (leaflets) of atrioventricular valves attach directly to A) papillary muscles. B) trabeculae carneae. C) chordae tendineae. D) interatrial septa. E) coronary sulci.
C
60) Coronary veins empty into the A) left atrium. B) left ventricle. C) right atrium. D) right ventricle. E) conus arteriosus.
C
67) Blood is supplied to the left atrium by the A) brachiocephalic artery. B) right coronary artery. C) left coronary artery. D) phrenic arteries. E) pulmonary arteries.
C
72) 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
73) ________ 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
C
79) 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
8) The visceral pericardium is the same as the A) mediastinum. B) parietal pericardium. C) epicardium. D) myocardium. E) endocardium.
C
83) 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.
C
87) 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.
C
90) When a blood clot forms on a ruptured plaque in a coronary artery, the condition is referred to as a(n) A) coronary spasm. B) myocardial infarction. C) coronary thrombosis. D) angina pectoris. E) pulmonary embolism.
C
95) 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.
C
41) 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 B and D
E
45) 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 epinephrine D) faster depolarization of the pacemaker potential E) all of the above
E
52) 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 a greater volume of blood than the right ventricle. C) the left ventricle produces a higher pressure than the right. D) both A and B E) both A and C
E
57) Cardiac muscle cells and skeletal muscle cells differ in a few ways. Which of the following is not one of them? A) Cardiac muscle cells are smaller in size. B) Cardiac muscle cells have a single, centered nucleus. C) Cardiac muscle cells branch. D) Skeletal muscle cells lack intercalated discs. E) Cardiac muscle cells lack transverse tubules.
E
62) 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
E
64) The ________ deliver(s) blood to the myocardium. A) right coronary artery B) right coronary vein C) superior vena cava D) left coronary artery E) both A and D
E
66) The connective tissue fibers of the myocardium A) add strength and prevent overexpansion of the heart. B) help distribute the forces of contraction. C) provide elasticity to help return the heart to its normal size. D) provide physical support for cardiac muscle. E) all of the above
E
68) A heart murmur might be caused by A) aortic valve stenosis. B) mitral valve insufficiency. C) pulmonic valve insufficiency. D) B or C E) A or B or C
E
75) ________ is to contraction as ________ is to relaxation. A) Systole; diastole B) Diastole; systole C) Filling; relaxing D) Ejection; filling E) both A and D
E
80) 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) A and B only E) A, B, and C
E
88) Drugs known as calcium channel blockers such as nifedipine can be used to A) decrease the force of cardiac contraction. B) decrease blood pressure. C) dilate the coronary arteries. D) produce a negative inotropic effect. E) all of the above
E
89) Cardiac cells damaged by infarction will show which of the following? A) switch to anaerobic metabolism. B) release of enzymes into the circulation. C) release of troponin T and I into the circulation. D) release of MB-CK into the circulation. E) all of the above
E
