Heart Quiz

29. When the heart is in fibrillation,

C) effective pumping of the ventricles ceases because the myocardial cells fail to work as a team, and the brain cannot get adequate oxygen.

30. Electrical shock to the heart is usually used to treat

A) ventricular fibrillation.

31. A heart rate of 125 beats per minute could be correctly termed

B) tachycardia.

32. Which event happens at the start of a cardiac cycle?

B) The SA node fires.

33. Which of the following events result in the first heart sound?

B) The AV valves close.

34. During the isovolumic phase of ventricular systole

B) the atrioventricular valves and semilunar valves are closed.

35. The volume of blood ejected from each ventricle during a contraction is called the

C) stroke volume.

36. The cardiac output is equal to

B) the product of heart rate and stroke volume.

37. During ventricular systole,

C) the AV valves are closed.

38. According to Starling's law of the heart, the cardiac output is directly related to the

E) end-systolic volume.

39. Drugs known as beta-blockers will

B) decrease heart rate.

40. In order for blood to enter the heart,

A) the atria must be in diastole.
B) the pressure in the atria must be lower than in the veins.

41. The term used to describe the amount of blood in the ventricle available to be pumped out of the heart during the next contraction is

C) end-diastolic volume (EDV).

42. The term that describes the volume of blood circulated by the heart in one minute is

A) cardiac output (CO).

43. Which of these will increase the heart rate?

A) sympathetic stimulation to the SA node
B) the application of epinephrine to the SA node

44. At an intercalated disc

C) two cardiac muscle cells are connected by gap junctions.

45. Autorhythmic cells

A) are also called pacemakers because they set the rate of the heartbeat.

46. The P wave of an ECG corresponds to

A) the depolarization of the atria.

47. The QRS complex of an ECG corresponds to

B) the progressive wave of ventricular depolarization.

48. Ventricular contraction

C) begins just after the Q wave.

50. the volume of blood circulated by the heart in one minute

A. cardiac output (CO)

51. the amount of blood pumped out of the heart during one contraction

D. stroke volume (SV)

52. the amount of blood left in the ventricle after it contracts

E. end-systolic volume (ESV)

49. Atrial contraction

A) begins during the first part of the P wave.

1 The most accurate definition of artery is a vessel that

C) transports blood away from the heart.

2. Capillaries are best described as

A) microscopic vessels in which blood exchanges material with the interstitial fluid.

3. The purpose of having valves in the cardiovascular system is to

B) thick walled vessels that convey blood away from the heart.

4. Which artery/arteries branch(es) most proximal to the beginning of the aorta at the heart?

C) coronary

5. The medical term for heart attack is

B) myocardial infarction.

6. The driving force for blood flow is a(n) __________ gradient.

C) pressure

7. Each of the following changes will result in increased blood flow to a tissue except one. Identify the exception.

B) decreased vessel diameter

8. Which parameters are associated with increased resistance?

A) reduced flow

9. As blood vessel length increases,

A) resistance increases.
B) flow decreases.

10. When a quantity is expressed as "4 cm/sec," what is being described is the

B) velocity of flow.

11. The function of the pericardial fluid is to

B) reduce friction between the heart and the pericardium.

12. In the heart, valves are located

A) between the atria and the ventricles.
B) between the ventricles and the arteries.

13. Which valves have chordae tendineae?

B) bicuspid and tricuspid valves

14. The term myogenic indicates that the heart muscle is the source of

C) the electrical signal that triggers heart contraction.

15. The action potential in a cardiac contractile cell causes

A) opening of L-type calcium channels.

16. The rapid depolarization phase of the action potentials of myocardial contractile cells is due to which ion(s)?

C) Na+

17. During the plateau phase of the action potentials of myocardial contractile cells, which ion(s) is/are crossing the membrane?

A) Ca2+
B) K+

18. The flattening of the action potentials of myocardial contractile cells, called the plateau phase, is due to a combination of __________ K+ permeability and __________ Ca2+ permeability.

D) decreasing, increasing

19. The flattening of the action potentials of myocardial contractile cells, called the plateau phase, is due to a combination of increasing Ca2+ __________ and decreasing K+__________.

A) influx, efflux

20. The end of the plateau phase is due to the __________ of Ca2+ channels and __________ of K+ channels.

D) closing, opening

21. The importance of the plateau phase of the action potential of myocardial cells is in

C) preventing tetanus.

22. Myocardial cells can generate action potentials spontaneously because they have

A) unstable ion channels.

23. If channels are permeable to

C) Ca2+.

25. The depolarization of the pacemaker action potential spreads to adjacent cells through

A) gap junctions.

26. The fibrous skeleton of the heart is important because it

A) forces electrical activity to be conducted through the atrioventricular node.

27. The AV node is important because it

A.) directs electrical impulses from the atria to the ventricles
B.) delays the transmission of the electrical impulses to the ventricles in order for the atria to finish contracting

28. In the condition known as complete heart block, what happens?

B) Electrical signals from the SA node never reach the ventricles, so the contraction of the atria is not coordinated with the contraction of the ventricles.

53. amount of blood in the ventricle available to be pumped out of the heart during one contraction

C. end-diastolic volume (EDV)

54. an AV valve that has three flaps

A) tricuspid valve

55. a semilunar valve that has the right ventricle on one side

D) pulmonary valve

56. also called the mitral valve

B) bicuspid valve

57. has three cuplike leaflets and has the aorta on one side

C) aortic valve

***Place these structures in the order that blood returning to the heart from the body would pass through them write after the letter 1,2,3,4,...

1 .....right atrium
2 .....right ventricle
3 .....pulmonary artery
4 .....pulmonary vein
5 .....left atrium
6 .....left ventricle

***Put these autorhythmic cells into the correct order for conveying electrical signals through a normal heart.

1 ............sinoatrial nodes
2 ............internodal pathway
3 ............atrioventricular node
4 ............bundle of His
5 ............left and right bundle branches
6 ............Purkinje fibers

70. which is not a portal system in the body?

D) adreno-pituitary sytem.

71. Left ventricular pressure is higher than pressure in the aorta during

B) ventricular diastole.

72. Abnormally slow conduction through the ventricles would change the __________ in an ECG tracing.

C) QRS complex

73. A certain drug decreases heart rate by producing hyperpolarization in the pacemaker cells of the heart. This drug probably binds to

B) muscarinic receptors.

74. Under which set of circumstances would the diameter of peripheral blood vessels be the greatest?

B) decreased sympathetic stimulation

75. Acetylcholine slows the heart rate by

C) increasing the permeability to K+.
D) decreasing the permeability to Ca2+.

76. Sympathetic stimulation increases the heart rate by

A) increasing ion influx thus increasing the rate of depolarization.

77. As a result of the long refractory period, cardiac muscle cannot exhibit

C) tetany.

78. Drugs known as calcium channel blockers can be used to

A) decrease the force of cardiac contraction.

79. If the membranes of the cardiac muscle cells in the SA node become more permeable to potassium ions,

B) the heart rate will decrease.

80. The ECG of a person suffering from complete heart block would show

E) more P waves than QRS complexes per minute.

81. If blood pressure doubled at the same time that the peripheral resistance doubled, the blood flow through a vessel would be

E) unchanged.

82. Which of the following conditions would have the greatest effect on peripheral resistance?

B) doubling the diameter of a vessel

83. If the connection between the AV node and bundle of His becomes blocked,

B) the ventricles will beat more slowly.

84. If a myocardial infarction results in the formation of scar tissue along the pathway of the left bundle branch,

A) cardiac arrhythmias may occur.

85. Manganese ions block the calcium channels in the cardiac muscle membrane. How would the presence of manganese in the extracellular fluid affect the contraction of the heart muscle?

C) The heart would beat less forcefully.

86. If there is a blockage between the AV node and the AV bundle, how will this affect the appearance of the electrocardiogram?

C) when the force of myocardial contraction is increased

87. In which of the following situations would the end-systolic volume (ESV) be the greatest?

B) when parasympathetic stimulation of the heart is increased

88. In which situation would the stroke volume be the greatest?

A) when venous return is increased

89. If the EDV is 140 mL, which other values are most likely to occur in a healthy, normal person?

A) The ESV could be 70 mL and the SV could be 70 mL.
C) The ESV could be 50 mL and the SV could be 90 mL.