Deck 18: The Heart

Question 1

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 chloride ions.
C) decreased membrane permeability to calcium ions.
D) decreased membrane permeability to sodium ions.
E) increased membrane permeability to potassium ions.

Answer 1

A

Question 2

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 lack transverse tubules.
C) Cardiac muscle cells have a single, centered nucleus.
D) Skeletal muscle cells lack intercalated discs.
E) Cardiac muscle cells branch.

Answer 2

B

Question 3

The normal pacemaker of the heart is located in the

A) both the left and right ventricles.
B) Purkinje fibers.
C) sinoatrial node.
D) wall of the left ventricle.
E) atrioventricular node.

Answer 3

C

Question 4

The marginal branch and posterior interventricular branch are branches of the

A) right coronary artery.
B) left coronary artery.
C) circumflex artery.
D) aorta.
E) coronary sinus.

Question 5

Drugs known as calcium channel blockers such as nifedipine can be used to

A) decrease blood pressure.
B) decrease the force of cardiac contraction.
C) produce a negative inotropic effect.
D) dilate the coronary arteries.
E) all of the above

Question 6

Tetanic muscle contractions don't occur in a normal cardiac muscle because

A) the refractory period lasts until the muscle relaxes.
B) cardiac muscle tissue contracts on its own.
C) the refractory period ends before the muscle reaches peak tension.
D) neural stimulation is lacking.
E) potassium channels outnumber sodium channels.

Question 7

Figure 18- 2 Cardiac Cycle
Use Figure 18- 2 to answer the following questions:
What volume is labeled "G" on the graph?

A) stroke volume
B) end- diastolic volume
C) cardiac output
D) end- systolic volume
E) both B and D

Question 8

David suffers from a prolapsed mitral valve. This condition would cause

A) increased effort by the right ventricle.
B) increased effort by the left ventricle.
C) systolic murmur.
D) both A and C
E) both B and C

Question 9

The T wave on an ECG tracing represents

A) ventricular depolarization.
B) ventricular contraction.
C) atrial depolarization.
D) ventricular repolarization.
E) atrial repolarization.

Question 10

Blood is supplied to the myocardium by

A) the coronary arteries.
B) arteries that branch from the pulmonary arteries.
C) the coronary sinus.
D) contact with blood in the pumping chambers.
E) both A and C

Question 11

Rupture of the papillary muscles in the left ventricle may result in

A) mitral regurgitation.
B) bicuspid regurgitation.
C) mitral valve prolapse.
D) bicuspid prolapse.
E) all of the above

Question 12

"An increase in end- diastolic volume increases the stroke volume" is a way of stating

A) Robin's law of the heart.
B) Hawking's law of the heart.
C) Starling's law of the heart.
D) Finch's law of the heart.
E) Sparrow's law of the heart.

Question 13

The right atrium receives blood from the

A) superior vena cava.
B) inferior vena cava.
C) coronary sinus.
D) A, B, and C
E) B and C only

Question 14

Figure 18- 2 Cardiac Cycle
Use Figure 18- 2 to answer the following questions:
When a blood clot forms on a ruptured plaque in a coronary artery, the condition is referred to as an)

A) angina pectoris.
B) myocardial infarction.
C) coronary spasm.
D) pulmonary embolism.
E) coronary thrombosis.

Question 15

A heartbeat lasts

A) 100 msec.
B) 370 msec.
C) 3 seconds.
D) 5 seconds.
E) none of the above

Question 16

Depolarization of the atria corresponds to the EKG's

A) S- T segment.
B) T wave.
C) P wave.
D) QT interval.
E) QRS complex.

Question 17

The visceral pericardium is the same as the

A) epicardium.
B) endocardium.
C) myocardium.
D) mediastinum.
E) parietal pericardium.

Question 18

The function of the atrium is to

A) collect blood.
B) pump blood into the systemic circuit.
C) pump blood to the lungs.
D) pump blood to the ventricle.
E) both A and D

Question 19

is to contraction as is to relaxation.

A) Systole; diastole
B) Diastole; systole
C) Filling; relaxing
D) Ejection; filling
E) both A and D

Question 20

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) 3, 2, 4, 5, 1.
B) 4, 2, 3, 5, 1.
C) 1, 4, 3, 2, 5.
D) 4, 3, 2, 5, 1.
E) 3, 5, 4, 2, 1.

Question 21

Figure 18- 1 The Heart
Use Figure 18- 1 to answer the following questions:
Identify the structure labeled "19."

A) pulmonary semilunar valve
B) ligamentum arteriosum
C) tricuspid valve
D) bicuspid valve
E) aortic semilunar valve

Question 22

The pulmonary arteries carry blood to the

A) liver.
B) lungs.
C) heart.
D) intestines.
E) brain.

Question 23

A heart murmur might be caused by

A) pulmonic valve insufficiency.
B) aortic valve stenosis.
C) mitral valve insufficiency.
D) B or C
E) A or B or C

Question 24

When the left ventricle contracts, the distance from the apex to the base

A) increases.
B) decreases.
C) remains unchanged.

Question 25

Which of the following descriptions matches the term near the left fifth intercostal space?

A) right atrium
B) pericardial cavity
C) visceral pericardium
D) aorta
E) apex of heart

Question 26

Acetylcholine slows the heart because it

A) opens potassium ion channels in SA node cells.
B) causes the pacemaker potential to depolarize more slowly.
C) causes the pacemaker potential to depolarize more quickly.
D) opens sodium- calcium ion channels in SA node cells.
E) A and C only

Question 27

In order to perform a CABG, a cardiac surgeon must

A) open the pericardial sac.
B) visualize the visceral pericardium.
C) visualize the parietal pericardium.
D) both A and B
E) A, B, and C

Question 28

When the semilunar valves close, the AV valves then

A) close.
B) make the third heart sound.
C) open.
D) both B and C
E) both A and C

Question 29

Figure 18- 1 The Heart
Use Figure 18- 1 to answer the following questions:
Which chamber receives oxygenated blood from the pulmonary circuit?

A) 16
B) 10
C) 5
D) 13
E) both 5 and 16

Question 30

In the middle of the thoracic cavity is a region occupied by the heart, great vessels, thymus, esophagus, and trachea called the

A) mediastinum.
B) cardiac notch.
C) pericardial space.
D) ventral cavity.
E) pleural space.

Question 31

Which of these would cause stroke volume to increase?

A) when venous return is increased
B) when venous return is decreased
C) when diastolic blood pressure is decreased
D) both A and C
E) both B and C

Question 32

Figure 18- 2 Cardiac Cycle
Use Figure 18- 2 to answer the following questions:
What occurs at the area labeled "D" on the graph?

A) AV valve opens
B) semilunar valve opens
C) diastolic refilling begins
D) both A and C
E) both B and C

Question 33

The term used to describe fluid collecting in the pericardial cavity that restricts the movement of the heart is known as

A) pericarditis.
B) pleural effusion.
C) cardiomyopathy.
D) mitral valve prolapse.
E) cardiac tamponade.

Question 34

The long plateau phase of the cardiac muscle action potential is due to

A) calcium channels remaining open.
B) increased membrane permeability to potassium ion.
C) movement of fewer sodium ions across the cell membrane.
D) decrease in the amount of calcium diffusing across the membrane.
E) increased membrane permeability to sodium ions.

Question 35

Most of the middle layer in the heart wall is composed of

A) fibrocytes.
B) cardiac myocytes.
C) chondrocytes.
D) smooth muscle cells.
E) epitheliocytes.

Question 36

Which of these is true about the atrial reflex?

A) also called Bainbridge reflex
B) triggered by increasing venous return
C) triggered by atrial mechanoreceptors
D) depends on sympathetic innervation
E) all of the above

Question 37

Artery is to _ _ as vein is to .

A) afferent; efferent
B) toward; away
C) afferent; away
D) efferent; afferent
E) none of the above

Question 38

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

Question 39

As a result of the long refractory period in the cardiac action potential, cardiac muscle cannot exhibit

A) fatigue.
B) recruitment.
C) tetany.
D) tonus.
E) treppe.

Question 40

The P wave of the electrocardiogram is a signal from

A) depolarization of the ventricles.
B) depolarization of the SA node.
C) repolarization of the atria.
D) depolarization of the atria.
E) depolarization of the AV node.

Question 41

Cardiac output is increased by 48)

A) more sympathetic stimulation.
B) increased end systolic volume.
C) increased stroke volume.
D) all of the above
E) A and C only

Question 42

What effect would compressing the inferior vena cava just below the diaphragm have on cardiac function?

A) Sympathetic stimulation of the heart would increase.
B) Cardiac output would increase.
C) Stroke volume would increase.
D) all of the above
E) A and B only

Question 43

Excess fluid in the _ causes cardiac tamponade.

A) pericardial cavity
B) left ventricle
C) visceral pericardium
D) both atria
E) apex of heart

Question 44

Figure 18- 2 Cardiac Cycle
Use Figure 18- 2 to answer the following questions:
Coronary veins empty into the

A) left atrium.
B) right atrium.
C) right ventricle.
D) left ventricle.
E) conus arteriosus.

Question 45

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) 5, 3, 1, 7, 8, 4, 2, 6
B) 1, 7, 3, 8, 2, 4, 6, 5
C) 5, 1, 3, 7, 8, 2, 4, 6
D) 1, 2, 7, 8, 3, 4, 6, 5
E) 5, 1, 3, 8, 7, 2, 4, 6

Question 46

Pacemaker cells isolated from the SA node generate action potentials at beats per minute.

A) 80-100
B) 140-180
C) 100-140
D) 40-60
E) 20-40

Question 47

The pulmonary veins carry blood to the

A) intestines.
B) lungs.
C) brain.
D) heart.
E) liver.

Question 48

During the T wave of the electrocardiogram, the ventricles are

A) contracting.
B) repolarizing.
C) depolarizing.
D) relaxing.
E) both B and D

Question 49

Blood leaves the right ventricle by passing through the

A) tricuspid valve.
B) bicuspid valve.
C) pulmonary valve.
D) mitral valve.
E) aortic valve.

Question 50

Contractions of the papillary muscles

A) eject blood from the ventricles.
B) close the atrioventricular valves.
C) eject blood from the atria into the ventricles.
D) close the semilunar valves.
E) prevent the atrioventricular valves from reversing into the atria.

Question 51

There are pulmonary veins.

A) 6
B) 2
C) 4
D) 8
E) none of the above

Question 52

Intercalated discs serve to transfer from cell to cell.

A) ionic currents
B) the force of contraction
C) action potentials
D) all of the above
E) A and B only

Question 53

is to slow heart rate as is to fast heart rate. 45)

A) Bradycardia; cardiomyopathy
B) Cardiac tamponade; bradycardia
C) Tachycardia; bradycardia
D) Bradycardia; tachycardia
E) none of the above

Question 54

If a patient's tricuspid valve was leaking during systole, what would happen?

A) diastolic murmur
B) regurgitation into the superior vena cava
C) regurgitation into the right atrium
D) A and B only
E) A, B, and C

Question 55

The right ventricle pumps blood to the

A) left ventricle.
B) aorta.
C) right and left lungs.
D) right atrium.
E) left atrium.

Question 56

Which of the following is greater during left ventricular systole?

A) the peak pressure in the aorta
B) the peak pressure in the ventricle
C) Neither is greater.

Question 57

At a heart rate of 60 beats/minute, a cardiac cycle lasts

A) 60 milliseconds.
B) 60 seconds.
C) 630 milliseconds.
D) 1 second.
E) 370 milliseconds.

Question 58

Activation of which kind of receptor causes heart rate to increase?

A) beta- two receptor
B) muscarinic receptor
C) preganglionic
D) alpha- one receptor
E) beta- one receptor

Question 59

The cardioacceleratory center activates sympathetic neurons and the cardioinhibitory center controls parasympathetic neurons.

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.
E) Both parts of the statement are true and relate to brainstem control of heart rate.

Question 60

The cusps leaflets) of atrioventricular valves attach directly to 46)

A) interatrial septa.
B) papillary muscles.
C) chordae tendineae.
D) trabeculae carneae.
E) coronary sulci.

Question 61

The atrioventricular valves permit blood flow

A) in opposite directions on the right and left.
B) in both directions.
C) in one direction only.
D) in many directions.
E) both A and D

Question 62

Depolarization of the ventricles is represented on an electrocardiogram by the

A) P wave.
B) PR complex.
C) S wave.
D) T wave.
E) QRS complex.

Question 63

The interventricular sulci and coronary sulcus contain

A) veins.
B) fat.
C) arteries.
D) all of the above
E) B and C only

Question 64

Cardiac output can be increased by all of the following except one. Choose the exception.

A) decreasing end systolic volume
B) increasing stroke volume
C) decreasing ejection fraction
D) increasing heart rate
E) increasing ejection fraction

Question 65

Stroke volume depends on

A) the pressure required to pump blood into the aorta.
B) the contractility of the ventricle.
C) end diastolic volume.
D) A and B only
E) A, B, and C

Question 66

Figure 18- 2 Cardiac Cycle
Use Figure 18- 2 to answer the following questions:
What volume is labeled "E" on the graph?

A) cardiac output
B) total cardiac volume
C) end- systolic volume
D) stroke volume
E) end- diastolic volume

Question 67

Figure 18- 2 Cardiac Cycle
Use Figure 18- 2 to answer the following questions:
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

Question 68

Which of these comparisons between skeletal and heart muscle is false?

A) both are striated.
B) both have T- tubules.
C) both rely entirely on oxidative metabolism for energy.
D) both trigger contraction by membrane depolarization.
E) both release calcium ion from the sarcoplasmic reticulum.

Question 69

The foramen ovale in the fetal heart is located in the

A) interatrial septum.
B) left ventricle.
C) right atrium.
D) left atrium.
E) right ventricle.

Question 70

Figure 18- 2 Cardiac Cycle
Use Figure 18- 2 to answer the following questions:
What occurs at "A" on the graph?

A) AV valve opens
B) AV valve closes
C) semilunar valve opens
D) end systolic volume
E) semilunar valve closes

Question 71

Figure 18- 2 Cardiac Cycle
Use Figure 18- 2 to answer the following questions:
The earlike extension of the atrium is the

A) auricle.
B) coronary sulcus.
C) atricle.
D) coronary sinus.
E) ventricle.

Question 72

Blood is supplied to the left atrium by the

A) left coronary artery.
B) pulmonary arteries.
C) phrenic arteries.
D) right coronary artery.
E) brachiocephalic artery.

Question 73

The heart is innervated by nerves.

A) sympathetic
B) neither parasympathetic nor sympathetic
C) parasympathetic
D) somatomotor
E) both parasympathetic and sympathetic

Question 74

Blood returning to the heart from the pulmonary circuit first enters the

A) right ventricle.
B) left atrium.
C) right atrium.
D) conus arteriosus.
E) left ventricle.

Question 75

The delivers) 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

Question 76

The left ventricle pumps blood to the

A) pulmonary circuit.
B) right ventricle.
C) right atrium.
D) lungs.
E) aorta.

Question 77

Analysis of the electrocardiogram can reveal all of the following, except the

A) heart rate.
B) effects of drugs and poisons.
C) duration of the ventricular action potential.
D) condition of the conducting system.
E) stroke volume.

Question 78

Abnormally slow depolarization of the ventricles would most change the shape of the in an ECG tracing.

A) R- T interval
B) P wave
C) T wave
D) QRS complex
E) P- R interval

Question 79

The first heart sound is heard when the

A) AV valves close.
B) atria contract.
C) AV valves open.
D) semilunar valves close.
E) blood enters the aorta.

Question 80

If there is a complete block between the SA node and the AV node, how would the ECG be affected?

A) There will be much bigger P waves.
B) The P- R interval will be shorter.
C) The ventricles will stop beating.
D) The QRS duration will be longer.
E) The rate of P waves will be faster than the rate of QRS complexes.