Chapter 21 The Cardiovascular System: The Heart

46) Papillary muscles of the right ventricle receive a signal to contract from (the)

B) moderator band.

9) The heart wall is composed of______ layers of tissues.

C) 3

15) One of the major differences between skeletal muscle and cardiac muscle is that cardiac muscle

C) lacks triads.

31) The left ventricle pumps blood into the

D) aorta.

36) Which of the following is an incorrect association?

A) atrioventricular—aortic valve

38) Blood is supplied to the muscle of the heart through the

A) coronary arteries.

43) When a clot forms in a coronary vessel and obstructs blood flow to the muscle, the condition is referred to as a(n)

A) coronary thrombosis.

26) The right ventricle

A) has thinner muscular walls than does the left ventricle.

48) Structures in the heart that carry electrical signals from the SA node to the AV node are called

A) internodal pathways.

25) The thick muscular partition that separates the two ventricles entire heart is the

A) interventricular septum.

57) In terms of time, at rest one cardiac cycle lasts

B) a little under 1 second.

13) Cardiac muscle cells obtain energy almost exclusively through

B) aerobic respiration.

20) Grooves on the external surface of the heart that divide the right and left ventricles include the

B) anterior interventricular sulcus.

22) The broad, superior portion of the heart is the

B) base.

47) Which of the following is a major component of the conduction system located in the interventricular septum?

B) bundle branches

27) The superior end of the right ventricle near the pulmonary valve is called (the)

B) conus arteriosus.

60) At rest the heart rate is usually by parasympathetic control.

B) decreased

55) During their period of systole, the inner volume of the atrial chambers

B) decreases.

10) The innermost layer of the heart wall is the

B) endocardium

8) The tough structure that surrounds the heart and helps reinforce and maintain position of the heart is the

B) pericardial sac.

16) The connective tissues of the heart

B) provide a strong fibrous cross-linkage system wrapping adjacent muscle cells together.

18) The fibrous skeleton of the heart is located

B) surrounding the heart valves.

59) Nodal activity of the heart may be influenced or modified by

B) the autonomic nervous system.

44) If a small blood clot passes through the heart and heart vessels, where is it most likely to cause damage if it becomes immobilized?

B) the left coronary artery

40) The most serious place for a blockage of a coronary artery is

B) the left coronary artery.

29) Which of the chambers of the heart can generate the greatest pressure?

B) the left ventricle

12) The contraction of any one cardiac muscle fiber

B) will cause the contraction of several others.

50) Pacemaker cells of the SA node depolarize about

C) 80-100 times per minute.

49) Which of the following is true of the contraction of the heart?

C) Cardiac contractions are coordinated by specialized conductive cardiac muscle fibers.

58) Which of the following conditions would cause the amount of blood entering the ascending aorta with each contraction of the heart to increase?

C) The amount of blood entering the right atrium of the heart was increased.

39) Which of the following is true of the coronary arteries?

C) They originate at the base of the aorta and are the first branches off this vessel.

33) Which of the following empty directly into the right atrium?

C) anterior cardiac veins

6) The visceral pericardium is also called the

C) epicardium.

11) Cardiac muscle differs from other muscle tissue in

C) having fibers connected to one another at intercalated discs.

23) The wall between the atria is called the

C) interatrial septum.

34) Blood travels from the left atrium to the left ventricle through the

C) mitral valve.

5) The serous membrane lining the pericardial cavity is the

C) pericardium.

32) The left atrium receives blood from the

C) pulmonary veins.

42) The coronary artery found under the right atrium is (the)

C) right coronary artery.

28) The moderator band is located in the

C) right ventricle.

2) Blood that is transported to and from all of the tissues of the body with the exception of the lungs is in the

C) systemic circuit.

51) The phase of the cardiac cycle during which each chamber contracts and pushes blood into the next structure is

C) systole.

1) The ability of the blood to supply oxygen and remove carbon dioxide from the tissues depends upon

C) the ability of the blood to remain in constant motion.

54) The chambers of the heart empty during

C) ventricular systole.

61) How would the heart rate be affected if there were a blockage of the AV node?

D) The electrical stimuli from the SA node would be normal, but the rate of contraction would slow or be irregular

3) Blood vessels traveling away from the heart are

D) arteries

19) Externally the posterior and inferior portions of the left ventricle form the

D) diaphragmatic surface.

53) During one cardiac cycle the ventricles spend most of their time in

D) diastole.

7) The reinforcing layer of the pericardium is the_____ layer

D) fibrous

41) Which of the following is supplied with blood by the left anterior descending artery?

D) left ventricle

24) Prominent muscular ridges that run along the inner surface of the auricle and across the adjacent atrial wall are the

D) pectinate muscles.

37) Valves of the heart open and close due to

D) pressure changes.

56) The most important factor in ensuring that blood moves in correct order through the heart is (the)

D) pressure of blood in each of the chambers at any given time.

30) The right ventricle is associated exclusively with which of the following?

D) pulmonary trunk

4) The heart has the unique ability to change its workload. On average the heart can pump between _____and _______liters of blood per minute.

E) 5; 30

17) The fibrous skeleton of the heart functions to

E) All of the answers are correct.

21) The anterior and posterior interventricular sulci on the outside of the heart contain

E) All of the answers are correct.

35) Which of the following valves is assisted in functioning by the papillary muscles?

E) All of the answers are correct.

45) The main pacemaker region of the heart is

E) in the wall of the right atrium.

14) Cardiac muscle cells do not________ need to contract.

E) nervous stimulation

52) During most of ventricular diastole, the

E) the ventricles are filling.