Deck 18: The Cardiovascular System: the Heart

Question 1

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

Answer 1

False

Question 2

Normal heart sounds are caused by which of the following events?

A) friction of blood against the chamber walls
B) opening of the heart valves
C) excitation of the sinoatrial (SA) node
D) closure of the heart valves

Answer 2

D

Question 3

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

Answer 3

True

Question 4

Auricles slightly increase blood volume in the ventricles.

Question 5

During the isovolumetric relaxation phase of the cardiac cycle, .

A) atrioventricular valves are closed; aortic and pulmonary valves are open
B) atrioventricular, aortic, and pulmonary valves are open
C) atrioventricular, aortic, and pulmonary valves are closed
D) atrioventricular valves are open; aortic and pulmonary valves are closed

Question 6

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

Question 7

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.

Question 8

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

Question 9

The myocardium receives its blood supply from the coronary arteries.

Question 10

Hemorrhage with a large loss of blood causes _.

A) no change in blood pressure but a change in respiration
B) a rise in blood pressure due to change in cardiac output
C) a lowering of blood pressure due to change in cardiac output
D) no change in blood pressure but a slower heart rate

Question 11

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.

Question 12

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

Question 13

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

Question 14

The left ventricular wall of the heart is thicker than the right wall in order to .

A) expand the thoracic cage during diastole
B) accommodate a greater volume of blood
C) pump blood with greater pressure
D) pump blood through a smaller valve

Question 15

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

Question 16

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

Question 17

If blood volume decreased dramatically due to massive bleeding, the autonomic nervous system will attempt to maintain cardiac output by increasing the heart rate.

Question 18

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

Question 19

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

Question 20

Tissues damaged by myocardial infarction are replaced by fibrous connective tissue.

Question 21

If the length of the absolute refractory period in cardiac muscle cells was the same as it is for skeletal muscle cells, .

A) tetanic contractions might occur, which would stop the heart's pumping action
B) contractions would last as long as the refractory period
C) pacemaker cells would cease to spontaneously depolarize
D) it would be much longer before cardiac cells could respond to a second stimulation

Question 22

Which of the following is NOT part of the intrinsic conduction system of the heart?

A) sinoatrial (SA) node
B) atrioventricular (AV) valve
C) atrioventricular (AV) node
D) bundle branches

Question 23

The foramen ovale .

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

Question 24

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

Question 25

Pectinate muscles are found in the _ .

A) atria and ventricles
B) right atrium and right ventricle only
C) atria only
D) ventricles only

Question 26

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) the atrioventricular (AV) node would become the pacemaker of the heart
C) parasympathetic stimulation would increase, causing a decrease in heart rate
D) the heart would stop, since the vagal nerves trigger the heart to contract

Question 27

The parietal pericardium _.

A) is found within the pericardial cavity
B) is separated from the fibrous pericardium by serous fluid
C) is also called the epicardium
D) lines the internal surface of the fibrous pericardium

Question 28

Which of the following receive(s) blood during ventricular systole?

A) pulmonary arteries only
B) aorta only
C) pulmonary veins only
D) both the aorta and pulmonary trunk

Question 29

The receiving chambers of the heart include the .

A) right and left atria
B) right and left ventricles
C) left atrium and ventricle
D) right atrium and ventricle

Question 30

Norepinephrine acts on the heart by .

A) causing a decrease in stroke volume
B) causing threshold to be reached more quickly
C) decreasing heart contractility
D) blocking the action of calcium

Question 31

If the SA node is not functioning, an ECG will show .

A) no P waves with a HR between 40-60 bpm
B) no QRS waves
C) higher P waves
D) more P waves than QRS waves

Question 32

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

Question 33

The atrioventricular (AV) valves are closed .

A) when the ventricles are in systole
B) by the movement of blood from atria to ventricles
C) while the atria are contracting
D) when the ventricles are in diastole

Question 34

Which of the following is NOT an age-related change affecting the heart?

A) thinning of the valve flaps
B) atherosclerosis
C) fibrosis of cardiac muscle
D) decline in cardiac reserve

Question 35

The fact that the left ventricle of the heart is thicker than the right ventricle reveals that it .

A) pumps a greater volume of blood
B) pumps blood against a greater resistance
C) sends blood through a smaller valve
D) expands the thoracic cage

Question 36

If cardiac muscle is deprived of its normal blood supply, damage would primarily result from .

A) an inadequate supply of lactic acid
B) a decrease in the number of available mitochondria for energy production
C) a lack of nutrients to feed into metabolic pathways
D) decreased delivery of oxygen

Question 37

The source of blood carried to capillaries in the myocardium would be the .

A) coronary veins
B) coronary arteries
C) coronary sinus
D) fossa ovalis

Question 38

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) ischemia
B) myocardial infarct
C) pericarditis
D) angina pectoris

Question 39

Which vessel(s) of the heart receive(s) blood from the right ventricle?

A) venae cavae
B) pulmonary trunk
C) pulmonary veins
D) aorta

Question 40

Which chambers of the heart contain oxygenated blood?

A) right and left ventricles
B) right atrium and ventricle
C) left atrium and ventricle
D) right and left atria

Question 41

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) end diastolic volume (EDV) decreases
B) venous return decreases
C) stroke volume decreases
D) preload increases

Question 42

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) stenotic aortic semilunar valve
B) deficient pulmonary semilunar valve
C) incompetent tricuspid valve
D) insufficient mitral (bicuspid) valve

Question 43

If the mitral valve is unable to close properly, .

A) blood could flow back into the right atrium
B) blood could flow back into the left atrium
C) blood could flow back into the left ventricle
D) blood could flow back into the right ventricle

Question 44

Which coronary artery is most responsible for supplying blood to the myocardial tissue of the left atrium?

A) anterior interventricular artery
B) posterior interventricular artery
C) circumflex artery
D) right marginal artery

Question 45

Define systole and diastole. Which heart chambers are usually referenced when these terms are used?

Question 46

The second heart sound is heard during which phase of the cardiac cycle?

A) isovolumetric relaxation
B) ventricular filling
C) ventricular ejection
D) isovolumetric contraction

Question 47

Select the correct statement about the function of myocardial cells.

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

Question 48

Select the correct statement about the heart valves.

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

Question 49

Define the terms end diastolic volume (EDV) and end systolic volume (ESV) and relate them to the calculation of stroke volume.

Question 50

Select the correct statement about cardiac output.

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

Question 51

Which is most responsible for the synchronized contraction of cardiac muscle tissue?

A) small motor units
B) branching cells
C) desmosomes
D) gap junctions

Question 52

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 fibrous cardiac skeleton forms the bulk of the heart.
C) The heart chambers are lined by the endomysium.
D) The myocardium is the layer of the heart that actually contracts.

Question 53

Isovolumetric contraction .

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

Question 54

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) 50 ml / beat
B) 170 ml / beat
C) 70 ml / beat
D) 120 ml / beat

Question 55

Compared to skeletal muscle, cardiac muscle _ _.

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

Question 56

During exercise, which of the following would occur on an electrocardiogram (ECG) compared to an individual at rest?

A) the time from one R to the R of the next heartbeat would decrease
B) the P-R interval would decrease
C) the S-T segment would decrease
D) the T wave would decrease

Question 57

Which is NOT a vessel that brings blood directly into the right atrium?

A) pulmonary vein
B) superior vena cava
C) coronary sinus
D) inferior vena cava

Question 58

During the period of ventricular filling, .

A) the atria remain in diastole
B) the aortic and pulmonary semilunar valves are open
C) blood flows mostly passively from the atria through the atrioventricular (AV) valves into the ventricles
D) pressure in the heart is at its peak

Question 59

The Frank-Starling Law states that, if other factors are constant, a .

A) higher end diastolic volume will produce a higher stroke volume
B) higher stroke volume will produce a higher end diastolic volume
C) higher stroke volume will produce a lower end diastolic volume
D) higher end diastolic volume will produce a lower stroke volume

Question 60

What is the expected heart rate when a heart is removed from a living body?

A) the heart would immediately stop beating
B) 100 beats / minute
C) 50 beats / minute
D) 75 beats / minute

Question 61

A Doppler ultrasound was performed on an infant who had symptoms of breathlessness and it was found that he had a patent ductus arteriosus. Discuss the location and function of the ductus arteriosus in the fetus and relate it to the reason for the infant's breathlessness.

Question 62

List the three vessels that bring oxygen-poor blood to the right atrium. Which regions of the body do they serve?

Question 63

What is the functional importance of the intercalated discs of cardiac muscle? What is the functional importance of the fibrous cardiac skeleton of the heart?

Question 64

An older woman complains of shortness of breath and intermittent fainting spells. Her doctor runs various tests and finds that the atrioventricular (AV) node is not functioning properly. What is the suggested treatment?

Question 65

Asystole is the total absence of ventricular electrical activity. Explain why defibrillation would not be effective in this situation.

Question 66

What two important functions does the intrinsic cardiac conduction system perform?

Question 67

List and define the three most important factors that affect stroke volume.

Question 68

A man enters the hospital complaining of chest pain. His history includes smoking, a stressful job, a diet heavy in saturated fats, lack of exercise, and high blood pressure. Although he is not suffering from a heart attack, his doctor explains to him that a heart attack is quite possible. What did the chest pain indicate? Why is this man a prime candidate for a heart attack?

Question 69

A 55-year-old male was admitted to the hospital with heart failure. He complains of increasing shortness of breath on exertion and needing to sleep on three pillows at night. On physical assessment, the nurse determines that his ankles and feet are very swollen. Which of these symptoms reflect left-sided heart failure and which reflect right-sided heart failure?

Question 70

The heart is called a "double pump" because there are two functionally separate circulations. Trace the pathway of each of these circulations and include the following information: heart chambers involved, major blood vessels involved, and general areas through which the blood flows. Begin with the right atrium.

Question 71

Why is oxygen so much more critical to the heart muscle than to skeletal muscles?

Question 72

Explain the role of pacemaker cells in cardiac tissue.

Question 73

A patient was admitted to the hospital with chest pains. On admission, his pulse was 110 and blood pressure was 96/64. According to his history, his normal pulse rate is usually between 80 and 88 and his blood pressure runs from 120/70 to 130/80. Explain why these changes in BP and HR occur.

Question 74

A 14-year-old girl undergoing a physical examination prior to being admitted to summer camp was found to have a loud diastolic murmur at the second intercostal space to the left side of the sternum. Explain the reason for the loud heart murmur associated with this girl's condition.

Question 75

A patient is prescribed a calcium channel blocker to prevent angina (chest pain), by decreasing the demand for oxygen. Explain why.

Question 76

What is the difference between the auricles and the atria?

Question 77

A patient takes a nitroglycerin tablet sublingually for chest pain. Nitroglycerin acts directly on smooth muscle, producing relaxation and vessel dilation. How would this relieve chest pain?