Download CHAPTER 20- The Cardiovascular System: The Heart

CHAPTER 20- The Cardiovascular System: The Heart
Choose the single best answer to each of the following questions.
1) The heart
A) lies just inferior to the diaphragm.
B) lies lateral to the lungs.
C) lies within the mediastinum
D) lies anterior to the sternum.
E) all of the above.
Answer: C
Reference: Page 696, Anatomy of the Heart
Level of Difficulty: Medium
2) The pericardium
A) anchors the heart to the diaphragm.
B) includes a serous outer layer.
C) includes a fibrous inner layer that is also called the epicardium.
D) secretes a mucoid film that reduces friction between the heart and the chest wall.
E) contains fluid between the fibrous and parietal serous layers.
Answer: A
Reference: Page 696, Anatomy of the Heart
Level of Difficulty: Medium
3) The heart wall
A) is composed of five layers of voluntary muscle arranged in diagonal, swirling bands.
B) includes the endocardium, or outermost layer, which is contiguous with the serous
pericardium.
C) has an inner layer called the epicardium, which is fused with the fibrous layer of the
pericardium.
D) consists largely of a middle layer of muscular tissue called the myocardium which performs the
pumping action of the heart.
E) All of these are correct.
Answer: D
Reference: Page 696, Anatomy of the Heart
Level of Difficulty: Medium
4) Which of the following is normally observed on the external surface of the heart?
A) an auricle on the anterior surface of each ventricle
B) a series of sulci that contain coronary blood vessels and a variable amount of fat
C) a shallow coronary sulcus that encircles most of the heart marking the boundary between the
inferior atria and superior ventricles
D) a shallow groove called the anterior interventricular sulcus on the anterior surface marking the
boundary between the right and left ventricles
E) a right ventricle which is much larger the left ventricle
Answer: B
Reference: Page 696, Anatomy of the Heart
Level of Difficulty: Medium
5) Which of the following are normally observed in the right atrium after birth?
A) openings from the coronary sinus, superior vena cava and inferior vena cava
B) pectinate muscles on the posterior wall
C) a foramen on the medial surface leading into the left atrium
D) a semilunar valve leading into the right ventricle
E) openings from the pulmonary veins
Answer: A
Reference: Page 696, Anatomy of the Heart
Level of Difficulty: Medium
6) Which of the following are normally observed in the left ventricle after birth?
A) a tricuspid valve allowing blood to enter from the left atrium
B) a semilunar valve allowing blood to exit to the pulmonary trunk
C) an incomplete ventricular septum
D) papillary muscles and chordae tendinae attached to the semilunar valve
E) raised bundles of cardiac muscle fibers called trabeculae carneae
Answer: E
Reference: Page 696, Anatomy of the Heart
Level of Difficulty: Medium
7) Which of the following is true of the left ventricle?
A) The left and right ventricles contract asynchronously.
B) The left ventricle has a lumen with a circular perimeter.
C) The left ventricle pumps blood against less resistance than the right ventricle.
D) The left ventricle pumps blood a shorter distance than the right ventricle.
E) The left ventricle has a thinner wall than the right ventricle.
Answer: B
Reference: Page 696, Anatomy of the Heart
Level of Difficulty: Medium
8) Each of the cardiac valves
A) opens and closes in response to changes in pressure.
B) attaches to the ventricular walls via chordae tendinae.
C) ensures one-way blood flow through the heart.
D) A and C are correct.
E) All of these are correct.
Answer: D
Reference: Page 704, Heart Valves and Circulation of Blood
Level of Difficulty: Medium
9) A medical student examines a valve that has been removed from a heart. He observes that the
valve has 3 crescent moon shaped cusps, but no chordae tendinae. What conclusion could he
draw based on those observations?
A) The valve is the tricuspid valve.
B) The valve is the bicuspid valve.
C) The valve is the pulmonary semilunar valve.
D) The valve is the aortic semilunar valve.
E) The valve could be either the aortic or the pulmonary semilunar valve.
Answer: E
Reference: Page 704, Heart Valves and Circulation of Blood
Level of Difficulty: Medium
10) Why doesn’t a significant amount of blood flow back into the vena cavae and coronary sinus
during atrial contraction?
A) the semilunar valves block the venous openings
B) the tricuspid valve blocks the venous openings
C) the contraction of the atria compresses and closes the venous openings
D) the bicuspid valve blocks the venous openings
E) the venous valves block the venous openings
Answer: C
Reference: Page 704, Heart Valves and Circulation of Blood
Level of Difficulty: Medium
11) Which of the following represents the correct sequence of parts through which blood flows
as it moves lower body to the to the left atrium?
1.
2.
3.
4.
5.
6.
7.
8.
9.
A)
B)
C)
D)
E)
Pulmonary veins
Superior vena cava
Right ventricle
Pulmonary valve
Pulmonary trunk and arteries
Inferior vena cava
Tricuspid valve
Right atrium
Lungs
1, 9, 5, 4, 3, 7, 8, 6, but never 2
2, 8, 7. 3, 4, 5, 9, 1, but never 6
1, 9, 5, 4, 3, 7, 8, 2, but never 6
6, 8, 7, 3, 4, 5, 9, 1, but never 2
6, 3, 7, 8, 4, 5, 9, 1, but never 2
Answer: D
Reference: Page 704, Heart Valves and Circulation of Blood
Level of Difficulty: Medium
12) Blood passing through the bicuspid valve will enter the
A) left atrium
B) left ventricle
C) right atrium
D) right ventricle
E) aorta
Answer: B
Reference: Page 704, Heart Valves and Circulation of Blood
Level of Difficulty: Medium
13) Blood in the coronary sinus will drain into the
A) left atrium
B) left ventricle
C) right atrium
D) right ventricle
E) aorta
Answer: C
Reference: Page 704, Heart Valves and Circulation of Blood
Level of Difficulty: Medium
14) All of the following statements about circulation of blood are true EXCEPT:
A) The systemic circulation circuit receives blood from the left ventricle.
B) The pulmonary circulation transports blood from the heart to the lungs and back to the heart.
C) The first blood vessel in the systemic circuit is the aorta.
D) The coronary circulation is part of the pulmonary circuit.
E) The right side of the heart is the pump for the pulmonary circuit.
Answer: D
Reference: Page 704, Heart Valves and Circulation of Blood
Level of Difficulty: Medium
15) Which of the following does not supply the heart with nutrient and oxygen rich blood?
A) anterior interventricular branch
B) circumflex artery
C) great cardiac vein
D) posterior interventricular branch
E) right marginal branch
Answer: C
Reference: Page 704, Heart Valves and Circulation of Blood
Level of Difficulty: Easy
16) Cardiac muscle tissue is characterized by all of these EXCEPT:
A) long, multinucleated, cylindrical cells
B) bifurcated (branched) cells
C) intercalated discs
D) numerous large mitochondria
E) striations
Answer: A
Reference: Page 708, Cardiac Muscle Tissue and the Cardiac Conduction System
Level of Difficulty: Medium
17) The autorhythmic cells of the heart
A) constitute approximately 90% of the cardiac myofibers.
B) depolarize to threshold spontaneously.
C) depolarize more slowly than other cardiac myofibers.
D) are found in the fibrous skeleton of the heart.
E) depolarize only in response to neurotransmitters or hormones.
Answer: B
Reference: Page 708, Cardiac Muscle Tissue and the Cardiac Conduction System
Level of Difficulty: Medium
18) The primary pacemaker of the heart is the
A) Purkinje fiber
B) AV bundle (bundle of His)
C) right bundle branch
D) SA node
E) left bundle branch
Answer: D
Reference: Page 708, Cardiac Muscle Tissue and the Cardiac Conduction System
Level of Difficulty: Easy
19) Place the following in order of the propagation of a cardiac action potential
1. Purkinje fibers
2. SA node
3. right and left bundle branches
4. AV bundle
5. AV node
A) 2, 4, 5, 3, 1
B) 5, 2, 4, 1, 3
C) 5, 2, 4, 3, 1
D) 2, 4, 3, 1, 4
E) 2, 5, 4, 3, 1
Answer: E
Reference: Page 708, Cardiac Muscle Tissue and the Cardiac Conduction System
Level of Difficulty: Medium
20) All of the following are true of the cardiac conduction system EXCEPT
A) The AV node can take over the pacemaking task if the SA node is damaged.
B) Autonomic nervous system impulses establish the fundamental rhythm of the heart.
C) The pacemaking ability of the AV bundle alone is not sufficient to maintain homeostasis.
D) Ectopic pacemakers may be stimulated by caffeine or nicotine.
E) ACh release by the parasympathetic division of the ANS decreases SA node depolarization.
Answer: B
Reference: Page 708, Cardiac Muscle Tissue and the Cardiac Conduction System
Level of Difficulty: Medium
21) Select the events that occur during the plateau phase of a cardiac contractile action potential
and place them in the order in which they occur during that phase.
1. rapid depolarization of the membrane
2. inactivation of the fast Na+ channels
3. action potential develops in neighboring cells
4. release of Ca2+ from the sarcoplasmic reticulum
5. opening of voltage-gated slow Ca2+ channels
6. opening of voltage-gated fast Na+ channels
7. entry of Ca2+ from the interstitial fluid
8. decreased permeability to K+ due to closing of some K+ channels
9. voltage-gated K+ channels open
10. closure of Ca2+ channels
11. restoration of the resting membrane potential
A) 5, 4, 7 and 8
B) 3, 6, 1, 2
C) 9 and 10, 11
D) 3, 6, 5, 4, 7 and 8
E) 3, 6, 1, 2, 9, 10, 11
Answer: A
Reference: Page 708, Cardiac Muscle Tissue and the Cardiac Conduction System
Level of Difficulty: Hard
22) The refractory period of cardiac muscle fibers
A) is a time interval during which another contraction is initiated.
B) is much shorter than their contraction period.
C) prevents tetany and allows the heart to act as a pump.
D) A and B are correct.
E) A, B and C are correct.
Answer: C
Reference: Page 708, Cardiac Muscle Tissue and the Cardiac Conduction System
Level of Difficulty: Medium
23) In cardiac muscle,
A) most of the ATP production is anaerobic.
B) most of the ATP used while at rest comes from oxidation of fatty acids.
C) no ATP is produced from creatine phosphate.
D) O2 is actively transported across the sarcolemma.
E) lactic acid production decreases during exercise.
Answer: B
Reference: Page 708, Cardiac Muscle Tissue and the Cardiac Conduction System
Level of Difficulty: Medium
24) Which of the following does an electrocardiogram detect?
A) cardiomegaly (enlargement of the heart)
B) ischemic coronary blood vessels
C) disturbances of the conduction pathway of the heart.
D) damage to certain regions of the heart
E) All of these may be detected by an ECG.
Answer: E
Reference: Page 708, Cardiac Muscle Tissue and the Cardiac Conduction System
Level of Difficulty: Medium
25) The QRS complex of the ECG is associated with
A) atrial depolarization
B) ventricular depolarization
C) SA node depolarization
D) ventricular repolarization
E) A and B are correct.
Answer: B
Reference: Page 708, Cardiac Muscle Tissue and the Cardiac Conduction System
Level of Difficulty: Easy
26) A patient’s ECG contains a prolonged P-Q interval, but is otherwise unremarkable. Which of
the following is true of this patient’s condition?
A) The patient is having an acute myocardial infarction.
B) The patient probably has hyperkalemia.
C) The patient probably has ventricular hypertrophy.
D) The patient may have coronary artery disease.
E) The patient probably has atrial atrophy.
Answer: D
Reference: Page 708, Cardiac Muscle Tissue and the Cardiac Conduction System
Level of Difficulty: Medium
27) Which of the following correlations between cardiac contractions and ECG waves is correct?
A) Atrial systole persists through the S-T segment.
B) All chambers are contracted during the period between the T wave and the next P wave.
C) Ventricular systole begins after the QRS complex appears.
D) Atrial diastole precedes the appearance of the QRS complex.
E) Ventricular diastole precedes the appearance of the T wave.
Answer: C
Reference: Page 708, Cardiac Muscle Tissue and the Cardiac Conduction System
Level of Difficulty: Hard
28) A single cardiac cycle
A) lasts 8 sec when the heart rate is 75 beats/minute.
B) forces blood from areas of lower pressure to areas of higher pressure.
C) occurs independently of electrical activity in the heart.
D) includes all of the events associated with one heart beat.
E) refers only to ventricular events.
Answer: D
Reference: Page 716, The Cardiac Cycle
Level of Difficulty: Medium
29) Which event occurs during ventricular systole?
A) depolarization of the SA node
B) filling of the atria
C) ventricular pressure drops
D) opening of the AV valves
E) isovolumetric contraction
Answer: E
Reference: Page 716, The Cardiac Cycle
Level of Difficulty: Medium
30) Which of the following describe the relaxation period of the cardiac cycle?
A) It is a time when the atria are contracted.
B) It is a time that becomes shorter as the heart rate increases.
C) It is a time when the AV valves are always closed.
D) It is the time when the ventricles receive most of the blood from the aorta.
E) It is a time when the SL valves are open.
Answer: B
Reference: Page 716, The Cardiac Cycle
Level of Difficulty: Medium
31) The amount of blood contained in a ventricle at the end of atrial systole is the
A) stroke volume
B) ejection fraction
C) end-diastolic volume
D) end-systolic volume
E) cardiac output
Answer: C
Reference: Page 716, The Cardiac Cycle
Level of Difficulty: Easy
32) During the cardiac cycle, there is an interval during which cardiac fibers are contracting but
not shortening. The intraventricular pressure increases, but the ventricular volume remains the
same. What is this interval called?
A) atrial systole
B) atrial diastole
C) ventricular diastole
D) isovolumetric relaxation
E) isovolumetric contraction
Answer: E
Reference: Page 716, The Cardiac Cycle
Level of Difficulty: Medium
33) Heart sounds
A) may be detected by an ECG.
B) are the results of the cardiac valves closing.
C) are the results of the cardiac valves opening.
D) are associated with smoothly flowing blood.
E) are best assessed on the posterior thoracic wall.
Answer: B
Reference: Page 716, The Cardiac Cycle
Level of Difficulty: Medium
34) Cardiac output
A) is the volume of blood ejected from the left ventricle into the aorta.
B) is the volume of blood ejected from the right ventricle into the pulmonary trunk.
C) is the product of the stroke volume and the heart rate.
D) A and B are correct.
E) A, B and C are correct.
Answer: C
Reference: Page 719, Cardiac Output
Level of Difficulty: Medium
35) A patient has an EDV of 90 mL and an ESV of 40 mL with a heart rate of 50. What is this
patient’s cardiac output?
A) 6500 mL/min or 6.5 L/min
B) 2000 mL/min or 2.0 L/min
C) 4500 mL/min or 4.5 L/min
D) 2500 mL/min or 2.5 L/min
E) 180 mL/min or 0.18 L/min
Answer: D
Reference: Page 719, Cardiac Output
Level of Difficulty: Medium
36) A patient’s maximum cardiac output is 20 L/min. Her resting cardiac output is 5 L/min. What is
the patient’s cardiac reserve?
A) 15 L/min
B) 100 L/min
C) 4 L/min
D) 50 L/min
E) 25 L/min
Answer: A
Reference: Page 719, Cardiac Output
Level of Difficulty: Medium
37) Which of the following correctly describes how stroke volume regulated?
A) by adjusting the preload, the pressure that must be overcome to open an SL valve
B) by adjusting the contractility, or strength of contraction of the heart at a given preload
C) by adjusting the afterload, or degree of stretch on the heart before it contracts
D) A and B are correct.
E) A, B and C are correct.
Answer: B
Reference: Page 719, Cardiac Output
Level of Difficulty: Medium
38) The Frank-Starling law of the heart states that
A) that increased filling time will decrease the force of contraction by the ventricles.
B) the right and left ventricles must pump equal amounts of blood with each heart beat.
C) a healthy heart will pump out all the blood that entered during the previous diastole.
D) the greater the preload on cardiac muscle fibers, the weaker the force of contraction will be.
E) the greater the preload on cardiac muscle fibers, the greater the force of contraction will be.
Answer: E
Reference: Page 719, Cardiac Output
Level of Difficulty: Medium
39) A patient has pulmonary edema but not peripheral edema. Which of the following is probably
true of the patient’s heart?
A) The patient’s left ventricle is failing.
B) The patient’s left atrium is failing.
C) The patient’s right ventricle is failing.
D) The patient’s right atrium is failing.
E) The patient’s heart is working normally.
Answer: A
Reference: Page 719, Cardiac Output
Level of Difficulty: Medium
40) Which of the following is NOT true of regulation of heart rate?
A) Nervous system control originates in the cardiovascular center of the medulla oblongata.
B) Sympathetic impulses travel to the heart primarily along the vagus (X) nerves.
C) The limbic system can influence the cardiovascular center of the medulla oblongata.
D) Proprio-, chemo-, and baroreceptors detect changes and influence the cardiovascular center.
E) Increased stimulation by the cardiac accelerator nerve increases heart rate.
Answer: B
Reference: Page 719, Cardiac Output
Level of Difficulty: Medium
41) Which of the following would be expected to slow heart rate and decrease cardiac output?
A) epinephrine
B) norepinephrine
C) ACh
D) hyponatremia
E) T3/T4
Answer: C
Reference: Page 719, Cardiac Output
Level of Difficulty: Medium
42) Which of the following statements is true of heart rate?
A) Newborns typically have heart rates of 50 beats/minute or less.
B) Men typically have slightly faster heart rates than women.
C) Athletes typically have faster heart rates than sedentary individuals.
D) Hyperthermia decreases heart rate.
E) Regular exercise tends to reduce resting heart rate in both males and females.
Answer: E
Reference: Page 719, Cardiac Output
Level of Difficulty: Medium
43) What is the relationship between exercise and the heart?
A) A person’s cardiovascular fitness can be improved with regular exercise.
B) Aerobic exercise decreases cardiac output and should be limited to twice a week.
C) A healthy person’s cardiovascular fitness declines after several weeks of training.
D) Regular exercise causes loss of cardiac muscle tissue.
E) During strenuous activity, a sedentary person’s cardiac output is greater than an athlete’s.
Answer: A
Reference: Page 722, Exercise and the Heart
Level of Difficulty: Easy
44) All of the following are true of the development of the heart EXCEPT:
A) The hole in the interatrial septum of the fetal heart is called the foramen ovale.
B) The septa of the heart develop around the seventh week of development.
C) Early in development, the heart consists of a pair of tubes.
D) The heart is derived from ectoderm and endoderm.
E) The heart begins to beat at the end of the third week of development.
Answer: D
Reference: Page 724, Development of the Heart
Level of Difficulty: Medium
45) All of the following are risk factors for coronary artery disease (CAD) EXCEPT
A) hyperlipidemia
B) obesity
C) type “A” personality
D) smoking
E) regular aerobic exercise
Answer: E
Reference: Page 726, Disorders: Homeostatic Imbalances
Level of Difficulty: Medium
46) A myocardial infarction
A) results from an interrupted blood supply to part of the heart.
B) causes death of part of the heart.
C) is usually treated with pro-coagulation therapy.
D) A and B are correct.
E) A, B, and C are correct.
Answer: D
Reference: Page 726, Disorders: Homeostatic Imbalances
Level of Difficulty: Medium
47) Which of the following is NOT associated with Tetralogy of Fallot?
A) interventricular septal defect
B) enlarged left ventricle
C) enlarged right ventricle
D) an aorta over-riding the ventricular septum
E) stenosed pulmonary SL valve
Answer: B
Reference: Page 726, Disorders: Homeostatic Disturbances
Level of Difficulty: Medium