Ch 18 Flashcards


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1

1) The myocardium receives its blood supply from the coronary arteries.

TRUE

2

2) Cardiac muscle has more mitochondria and depends less on a continual supply of oxygen than does skeletal muscle.

FALSE

3

3) Anastomoses among coronary arterial branches provide collateral routes for blood delivery to the heart muscle.

TRUE

4

4) Congestive heart failure means that the pumping efficiency of the heart is depressed so that there is inadequate delivery of blood to body tissues.

TRUE

5

5) Tissues damaged by myocardial infarction are replaced by connective tissue.

TRUE

6

6) The left side of the heart pumps the same volume of blood as the right.

TRUE

7

7) When released in large quantities, thyroxine, a thyroid gland hormone, causes a sustained increase in heart rate.

TRUE

8

8) Arterial blood supply to heart muscle is continuous whether the heart is in systole or diastole.

FALSE

9

9) Auricles slightly increase blood volume in the ventricles.

FALSE

10

10) The "lub" sounds of the heart are valuable in diagnosis because they provide information about the function of the heart's pulmonary and aortic semilunar valves.

FALSE

11

11) Autonomic regulation of heart rate is via two reflex centers found in the pons.

FALSE

12

12) The papillary muscles contract after the other ventricular muscles so that they can take up the slack on the chordae tendineae before the full force of ventricular contractions sends blood against the atrioventricular (AV) valve flaps.

FALSE

13

13) An electrocardiogram (ECG) provides direct information about valve function.

FALSE

14

14) As pressure in the aorta rises due to atherosclerosis, more ventricular pressure is required to open the aortic valve.

TRUE

15

15) If the aorta and pulmonary trunk were switched, oxygen rich blood would be pumped from the left ventricle to the lungs.

TRUE

16

16) Heart tissue is supplied with nutrients primarily by diffusion from the heart chambers through the myocardium.

FALSE

17

1) Normal heart sounds are caused by which of the following events? A) friction of blood against the chamber walls B) closure of the heart valves C) opening of the heart valves D) excitation of the sinoatrial (SA) node

B

18

2) Which of the events below does NOT occur when the semilunar valves are open? A) Ventricles are in diastole. B) Blood enters pulmonary arteries and the aorta. C) Ventricles are in systole. D) AV valves are closed.

A

19

3) Hemorrhage with a large loss of blood causes ________. A) no change in blood pressure but a slower heart rate B) a lowering of blood pressure due to change in cardiac output C) no change in blood pressure but a change in respiration D) a rise in blood pressure due to change in cardiac output

B

20

4) Damage to the ________ causes heart block. A) sinoatrial (SA) node B) atrioventricular (AV) node C) atrioventricular (AV) bundle D) atrioventricular (AV) valves

B

21

5) The P wave of a normal electrocardiogram indicates ________. A) ventricular repolarization B) atrial depolarization C) atrial repolarization D) ventricular depolarization

B

22

6) Blood within the pulmonary veins returns to the ________. A) left atrium B) right atrium C) right ventricle D) left ventricle

A

23

7) The condition where fluid compresses the heart and limits its ability to contract is called ________. A) cardiac tamponade B) myocardial infarction C) pericarditis D) angina pectoris

A

24

8) The term for pain associated with deficient blood delivery to the heart that may be caused by the transient spasm of coronary arteries is ________. A) pericarditis B) myocardial infarct C) angina pectoris D) ischemia

C

25

9) To auscultate the aortic semilunar valve, you would place your stethoscope in the ________. A) second intercostal space to the right of the sternum B) second intercostal space to the left of the sternum C) fifth right intercostal space D) fifth intercostal space inferior to the left nipple

A

26

10) The source of blood carried to capillaries in the myocardium would be the ________. A) coronary arteries B) coronary veins C) coronary sinus D) fossa ovalis

A

27

11) The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it ________. A) pumps blood against a greater resistance B) expands the thoracic cage C) sends blood through a smaller valve D) pumps a greater volume of blood

A

28

12) Which of the following factors does NOT influence heart rate? A) gender B) body temperature C) age D) skin color

D

29

13) Which of the following is NOT an age-related change affecting the heart? A) decline in cardiac reserve B) thinning of the valve flaps C) atherosclerosis D) fibrosis of cardiac muscle

B

30

14) If cardiac muscle is deprived of its normal blood supply, damage would primarily result from ________. A) decreased delivery of oxygen B) an inadequate supply of lactic acid C) a lack of nutrients to feed into metabolic pathways D) a decrease in the number of available mitochondria for energy production

A

31

15) If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, ________. A) contractions would last as long as the refractory period B) tetanic contractions might occur, which would stop the heart's pumping action C) pacemaker cells would cease to spontaneously depolarize D) it would be much longer before cardiac cells could respond to a second stimulation

B

32

16) Norepinephrine acts on the heart by ________. A) causing threshold to be reached more quickly B) blocking the action of calcium C) causing a decrease in stroke volume D) decreasing heart contractility

A

33

17) If the vagal nerves to the heart were cut, the result would be that ________. A) the heart rate would increase by about 25 beats per minute B) parasympathetic stimulation would increase, causing a decrease in heart rate C) the atrioventricular (AV) node would become the pacemaker of the heart D) the heart would stop, since the vagal nerves trigger the heart to contract

A

34

18) The foramen ovale ________. A) connected the two atria in the fetal heart B) is a condition in which the heart valves do not completely close C) is a connection between the pulmonary trunk and the aorta in the fetus D) is a shallow depression in the interventricular septum

A

35

19) Which vessel(s) of the heart receive(s) blood from the right ventricle? A) pulmonary trunk B) aorta C) pulmonary veins D) venae cavae

A

36

20) Which of the following is NOT part of the intrinsic conduction system of the heart? A) sinoatrial (SA) node B) atrioventricular (AV) node C) bundle branches D) atrioventricular (AV) valve

D

37

21) The atrioventricular (AV) valves are closed ________. A) when the ventricles are in diastole B) while the atria are contracting C) when the ventricles are in systole D) by the movement of blood from atria to ventricles

C

38

22) When viewing a dissected heart, it is easy to visually discern the right and left ventricles by ________. A) tracing out where the auricles connect B) locating the base C) noticing the thickness of the ventricle walls D) finding the papillary muscles

C

39

23) Select the correct statement about the heart valves. A) The mitral (bicuspid) valve separates the right atrium from the right ventricle. B) The atrioventricular (AV) valves prevent backflow of blood into the atria during ventricular contraction. C) Aortic and pulmonary semilunar valves control the flow of blood into the heart. D) The tricuspid valve divides the left atrium from the left ventricle.

B

40

24) Select the correct statement about the function of myocardial cells. A) The refractory period in skeletal muscle is much longer than that in cardiac muscle. B) Cardiac muscle cells are innervated by sympathetic, parasympathetic, and somatic nerve fibers so that the nervous system can increase heart rate. C) The entire heart contracts as a unit or it does not contract at all. D) The influx of potassium ions from extracellular sources is the initiating event in cardiac muscle contraction.

C

41

25) Select the correct statement about the structure of the heart wall. A) Connective tissue in the heart wall aids in the conduction of the action potential. B) The myocardium is the layer of the heart that actually contracts. C) The fibrous cardiac skeleton forms the bulk of the heart. D) The heart chambers are lined by the endomysium.

B

42

26) Compared to skeletal muscle, cardiac muscle ________. A) has more nuclei per cell B) lacks striations C) cells are larger than skeletal muscle cells D) has gap junctions that allow it to act as a functional syncytium

D

43

27) During the period of ventricular filling ________. A) the aortic and pulmonary semilunar valves are open B) blood flows mostly passively through the atria and the open atrioventricular (AV) valves into the ventricles C) the atria remain in diastole D) pressure in the heart is at its peak

B

44

28) The second heart sound is heard during which phase of the cardiac cycle? A) ventricular filling B) isovolumetric relaxation C) isovolumetric contraction D) ventricular ejection

B

45

29) If we were able to artificially alter the membrane permeability of pacemaker cells so that sodium influx is more rapid, ________. A) tetanic contraction would occur due to the short absolute refractory period of cardiac muscle B) threshold is reached more quickly and heart rate would increase C) potassium channels compensate and no change in heart rate would occur D) heart rate would decrease, but blood pressure would rise due to the excess sodium present

B

46

30) Select the correct statement about cardiac output. A) If a semilunar valve were partially obstructed, the end systolic volume in the affected ventricle would be decreased. B) Decreased venous return will result in increased end diastolic volume. C) A slow heart rate increases end diastolic volume, stroke volume, and force of contraction. D) Stroke volume increases if end diastolic volume decreases.

C

47

31) During contraction of heart muscle cells ________. A) all of the calcium required for contraction comes from storage in the sarcoplasmic reticulum B) some calcium enters the cell from the extracellular space and triggers the release of larger amounts of calcium from intracellular stores C) calcium is prevented from entering cardiac fibers that have been stimulated D) the action potential is prevented from spreading from cell to cell by gap junctions

B

48

32) Isovolumetric contraction ________. A) refers to the short period during ventricular systole when the ventricles are completely closed chambers B) occurs immediately after the aortic and pulmonary semilunar valves close C) occurs while the atrioventricular (AV) valves are open D) occurs only in people with heart valve defects

A

49

33) Given an end diastolic volume (EDV) of 120 ml / beat and an end systolic volume (ESV) of 50 ml / beat, the stroke volume (SV) would be ________. A) 170 ml / beat B) 70 ml / beat C) 120 ml / beat D) 50 ml / beat

B

50

34) When does the period of atrial repolarization occur? A) during the T wave B) ventricular contraction C) ventricular depolarization D) during the P wave

C

51

35) During exercise, which of the following would occur on an electrocardiogram (ECG) compared to an individual at rest? A) the T wave would decrease B) the P-R interval would decrease C) the S-T segment would decrease D) the time from one R to the R of the next heartbeat would decrease

D

52

36) Which of the following transports oxygen-rich blood? A) pulmonary vein B) pulmonary artery C) pulmonary trunk D) superior vena cava

A

53

37) What is the expected heart rate when a heart is removed from a living body? A) 75 beats / minute B) 100 beats / minute C) 50 beats / minute D) the heart would immediately stop beating

B

54

38) While auscultating heart sounds during a checkup, Andy's doctor hears a high-pitched sound during ventricular contraction. Which type of valve could cause this? A) incompetent tricuspid valve B) deficient pulmonary semilunar valve C) insufficient mitral (bicuspid) valve D) stenotic aortic semilunar valve

D

55

39) Exercise results in skeletal muscles compressing veins which encourages blood to return to the heart. In this scenario, which of the following is correct? A) preload increases B) venous return decreases C) stroke volume decreases D) end diastolic volume (EDV) decreases

A