Deck 10: The Cardiovascular System

Question 1

What are the major branches of the left coronary artery?
1) Anterior descending
2) Circumflex
3) Coronary sinus
4) Posterior descending

A)1, 2, and 3 only
B)2 and 4 only
C)1 and 2 only
D)2 and 3 only

Answer 1

C

Question 2

What are the first arteries to branch off the ascending aorta?

A) Brachiocephalic
B) Carotid
C) Coronary
D) Subclavian

Answer 2

C
Explanation: Two main coronary arteries, a left and a right, arise from the root of the aorta.

Question 3

Mixing of venous blood with arterial blood (a right-to-left shunt) occurs normally because of which of the following?
1) Congenital cardiac defects
2) Bronchial venous drainage
3) Thebesian venous drainage in the heart

A)1, 2, and 3
B)2 and 3 only
C)1 only
D)2 only

Answer 3

B

Question 4

Which of the following mechanisms facilitate venous return to the heart?
1) Sodium/potassium pump
2) Sympathetic venomotor tone
3) Cardiac suction
4) Skeletal muscle contraction

A)1 and 2 only
B)2, 3, and 4 only
C)1, 2, 3, and 4
D)3 and 4 only

Question 5

The semilunar (pulmonary and aortic) valves do which of the following?

A) Cause almost the entire afterload for the ventricles.
B) Consist of two half-moon or crescent-shaped cusps.
C) Prevent arterial backflow during ventricular relaxation.
D) Separate the ventricles from their arterial outflow tracts.

Question 6

What in essence is Frank-Starling's law of the heart?

A) The greater the stretch, the stronger the contraction.
B) The less the afterload, the greater the ejection fraction.
C) Describes the inverse relationship between diameter and resistance to flow.
D) Curves show the hysteresis variations between systole and diastole.

Question 7

Before draining into the right atrium, where do the large veins of the coronary circulation gather together?

A) Coronary sinus
B) Left posterior coronary vein
C) Right coronary sulcus
D) Thebesian veins

Question 8

The mitral (bicuspid) valve does which of the following?

A) Prevents atrial backflow during ventricular contraction.
B) Separates the right atrium and the left atrium.
C) Separates the right atrium and the right ventricle.
D) Separates the right ventricle and the pulmonary artery.

Question 9

Most of the muscle mass of the heart is located in which chamber?

A) Left atrium (LA)
B) Left ventricle (LV)
C) Right atrium (RA)
D) Right ventricle (RV)

Question 10

The apex of the heart (tip of the left ventricle) lies just above the diaphragm at a level corresponding to which intercostal space?

A) Fourth
B) Fifth
C) Sixth
D) Seventh

Question 11

The branches of the left coronary artery DO NOT supply which area of the heart?

A) Majority of the interventricular septum
B) Majority of the left ventricle
C) Majority of the left atrium
D) Sinus node

Question 12

What is the ability of myocardial tissue to propagate electrical impulses?

A) Automaticity
B) Conductivity
C) Contractility
D) Excitability

Question 13

What is the loose membranous sac that encloses the heart?

A) Endocardium
B) Mesothelium
C) Myocardium
D) Pericardium

Question 14

Intercalated discs in the myocardium perform a very important function. Which of the following describes that function?

A) Absolute refractory period
B) Automaticity
C) Contractility
D) Electrical conduction

Question 15

Which vessels in the body act like faucets, controlling the flow of blood into the capillary beds?

A) Arteries
B) Arterioles
C) Veins
D) Venules

Question 16

What makes it impossible for the myocardium to go into tetany?

A) Absolute refractory period
B) Automaticity
C) Cardiac myofibrils
D) Intercalated discs

Question 17

Narrowing of the mitral valve (mitral stenosis) results in which of the following?

A) Increased afterload on left ventricle
B) Increased preload on right ventricle
C) Increased pulmonary congestion
D) Systemic hypertension

Question 18

Tissue layers making up the heart wall include which of the following?
1) Endocardium
2) Epicardium
3) Myocardium

A)1, 2, and 3
B)2 and 3 only
C)2 only
D)1 and 3 only

Question 19

Why are the vessels of the venous system, particularly the small venules and veins, termed capacitance vessels?

A) They transmit and maintain the head of perfusion pressure.
B) They can alter their capacity to maintain adequate perfusion.
C) They determine the afterload on the left ventricle.
D) They maintain a constant environment for the body's cells.

Question 20

What circulatory system is referred to as a low-pressure, low-resistance system?

A) Left heart
B) Pulmonary vascular bed
C) Right heart
D) Systemic vascular bed

Question 21

Which of the following factors determine cardiac stroke volume?
1) Ventricular preload
2) Ventricular afterload
3) Ventricular contractility

A)1 and 2 only
B)1 and 3 only
C)2 and 3 only
D)1, 2, and 3

Question 22

What is the primary function of local or intrinsic cardiovascular control mechanisms?

A) Alter local blood flow according to tissue needs.
B) Alter the rate of cardiac contractions.
C) Maintain a basal level of systemic vascular tone.
D) Control the capacity of the venous reservoir.

Question 23

The cardiovascular system regulates perfusion mainly by altering which of the following?

A) Capacity and resistance of blood vessels
B) Rate of cardiac contractions
C) Strength of cardiac contractions
D) Volume of cardiac contractions

Question 24

What is an approximate normal resting cardiac output for a healthy adult?

A) 75 ml/min
B) 500 ml/min
C) 2000 ml/min
D) 5000 ml/min

Question 25

Which of the following equations best depicts the factors determining mean arterial blood pressure?

A) Mean arterial pressure = cardiac output ÷ vascular resistance
B) Mean arterial pressure = cardiac output $\times$ vascular resistance
C) Mean arterial pressure = right atrial pressure - aortic pressure
D) Mean arterial pressure = vascular resistance ÷ cardiac output

Question 26

Smooth muscle relaxation and vessel dilation are caused mainly by which of the following?
1) Action of local metabolites
2) Cholinergic stimulation
3) Stimulation of beta-adrenergic receptors

A)1 and 3 only
B)2 and 3 only
C)1 and 2 only
D)1, 2, and 3

Question 27

Which of the following statements is true?

A) Pulmonary vascular resistance (PVR) is equal to systemic resistance.
B) Pulmonary vasculature is a high-pressure, high-resistance circulation.
C) Systemic vascular resistance (SVR) is less than PVR.
D) SVR is normally approximately 10 times higher than PVR.

Question 28

Central mechanisms cause contraction and increased resistance to blood flow mainly through which of the following?

A) Adrenergic stimulation and the release of norepinephrine
B) Cholinergic stimulation and the release of acetylcholine
C) Cholinergic stimulation and the release of norepinephrine
D) Stimulation of specialized alpha-adrenergic receptors

Question 29

Which portion of the nervous system is mainly responsible for the central control of the blood flow?

A) Higher brain centers
B) Parasympathetic nervous system
C) Somatic (voluntary) nervous system
D) Sympathetic nervous system

Question 30

Which of the following variation(s) control(s) blood flow to the heart?
1) Local metabolic control mechanisms
2) Local myogenic control mechanisms
3) Central neural innervation

A)1, 2, and 3
B)2 and 3 only
C)1 only
D)1 and 3 only

Question 31

Stroke volume can be calculated using which formula?

A) Ejection fraction $\times$ heart rate
B) End-diastolic volume - end-systolic volume
C) Ejection fraction $\times$ end-systolic volume
D) Cardiac output ÷ end-diastolic volume

Question 32

Central, or extrinsic, control of the cardiovascular system occurs through the action of which of the following?
1) Autonomic nervous system
2) Circulating humoral agents
3) Local metabolites

A)1, 2, and 3
B)2 and 3 only
C)3 only
D)1 and 2 only

Question 33

Which of the following equations would you use to compute systemic vascular resistance?

A) (Mean aortic pressure $\times$ right atrial pressure) ÷ CO
B) (Mean aortic pressure/right atrial pressure) $\times$ CO
C) (Mean aortic pressure - right atrial pressure) ÷ CO
D) (Right atrial pressure - mean aortic pressure) ÷ CO

Question 34

During exercise, cardiac output increases dramatically, but mean arterial blood pressure rises very little. Why is this so?

A) Venules constrict, increasing vascular resistance.
B) Arterioles dilate, decreasing vascular capacity.
C) Arterioles constrict, increasing vascular resistance.
D) Muscle vessels dilate, increasing vascular capacity.

Question 35

Central control of vasomotor tone has its greatest impact on which of the following vessels?
1) Arterioles (resistance vessels)
2) Veins (capacitance vessels)
3) Microcirculation (exchange vessels)

A)2 and 3 only
B)1 and 2 only
C)3 only
D)1, 2, and 3

Question 36

Which of the following formulas is used to calculate the total amount of blood pumped by the heart per minute, or cardiac output?

A) Blood pressure $\times$ SV
B) Rate $\times$ SV
C) SV ÷ rate
D) SV $\times$ vascular resistance

Question 37

The underlying goal of the body's cardiovascular control mechanisms is to ensure that all tissues receive which of the following?

A) Blood flow according to their mass
B) Blood flow according to their size
C) Equivalent amounts of blood flow
D) Perfusion according to their metabolic needs

Question 38

Which of the following variations control blood flow to the brain?

A) Central neural innervation
B) Circulation of humoral agents
C) Local metabolic control mechanisms
D) Local myogenic control mechanisms

Question 39

Mean arterial blood pressure can be regulated by changing which of the following?
1) Capacity of the circulatory system
2) Effective volume of circulating blood
3) Tone of the capacitance vessels (veins)

A)1 and 2 only
B)2 only
C)1, 2, and 3
D)3 only

Question 40

During blood loss due to hemorrhage, perfusing pressures can be kept near normal until the volume loss overwhelms the system. Why is this so?

A) Arteries constrict, increasing vascular resistance.
B) Arterioles dilate, decreasing vascular capacity.
C) Muscle vessels dilate, increasing vascular capacity.
D) Venules constrict, decreasing vascular capacity.

Question 41

Immediately following the P wave of the electrocardiogram, an A wave appears on both the left and right heart pressure graphs. This A wave corresponds to which of the following?

A) Atrial contraction
B) Atrioventricular valve closure
C) Semilunar valve closure
D) Ventricular contraction

Question 42

Opening of the semilunar valves occurs when which of the following occurs?

A) The pressures in the arteries exceed those in the ventricles.
B) The pressures in the atria exceed those in the ventricles.
C) The pressures in the ventricles exceed those in the aorta and pulmonary artery.
D) The pressures in the ventricles exceed those in the atria.

Question 43

The first heart sound is associated with what mechanical event of the cardiac cycle?

A) Atrioventricular valve closure
B) Atrioventricular valve opening
C) Semilunar valve closure
D) Semilunar valve opening

Question 44

Where are the central centers responsible for regulating the cardiovascular system located?

A) Aortic bodies
B) Brainstem
C) Carotid arteries
D) Cerebral hemispheres

Question 45

What is the affect on the cardiovascular medullary centers when the cerebral carbon dioxide is low?

A) Excitatory
B) Inhibitory
C) No affect
D) Increased vascular tone

Question 46

The heart's ability to vary stroke volume based solely on changes in end-diastolic volume is based on what mechanism?

A) Automaticity
B) Autoregulation
C) Bohr equation
D) Frank-Starling's law

Question 47

The semilunar valves close when which of the following occurs?

A) The pressures in the arteries exceed those in the ventricles.
B) The pressures in the ventricles and arteries become equal.
C) The pressures in the atria exceed those in the ventricles.
D) The pressures in the ventricles exceed those in the atria.

Question 48

Toward the end of systole, as repolarization starts (indicated by the T wave), the ventricles begin to relax. Which of the following will occur next?

A) Rapid rise in ventricular pressures.
B) Arterial pressures exceed ventricular pressures.
C) Closure of the atrioventricular valves.
D) Opening of semilunar valves.

Question 49

What is a normal cardiac ejection fraction?

A) 24%
B) 44%
C) 64%
D) 84%

Question 50

Changes in the rate of cardiac contractions are affected primarily by changes in which of the following?

A) Sympathetic or parasympathetic tone
B) Ventricular afterload
C) Ventricular contractility
D) Ventricular preload

Question 51

In order to function effectively, the central cardiovascular control center must receive signals regarding changes in blood volume or pressure. From where do these signals come?

A) Central chemoreceptors
B) Hypothalamus
C) Peripheral baroreceptors
D) Skeletal muscles

Question 52

What are the major effects of peripheral chemoreceptor stimulation?

A) Decreased drive to breathe
B) Decreased production of erythropoietin
C) Vasoconstriction and increased heart rate
D) Vasodilation and increased stroke volume

Question 53

Which factor stimulates the carotid and aortic chemoreceptors?

A) High carbon dioxide levels
B) High oxygen (O₂) levels
C) High pH levels
D) High 2,3-DPG levels

Question 54

Considering the negative feedback system for the control of blood pressure, when a blood pressure rise is noted in the arterial receptors, what is the expected response?

A) Arterial vasoconstriction
B) Decreased inotropic state
C) Increased heart rate
D) Venoconstriction

Question 55

Vascular low-pressure baroreceptors have their greatest impact on which system?

A) Central chemoreceptors
B) Endocrine
C) Exocrine
D) Renin-angiotensin

Question 56

Significant loss of blood volume causes an increase in which of the following?
1) Vascular tone
2) Secretion of antidiuretic hormone (ADH)
3) Heart rate

A)1, 2, and 3
B)2 and 3 only
C)1 and 3 only
D)1 and 2 only

Question 57

During the normal events of the cardiac cycle, which of the following statements is true?

A) Electrical depolarization follows mechanical contraction.
B) Electrical depolarization precedes mechanical contraction.
C) Heart sounds precede electrical depolarization.
D) Heart sounds precede cardiac valve opening or closing.

Question 58

Given a stroke volume of 40 ml and an end-diastolic volume (EDV) of 70 ml, what is the patient's ejection fraction (EF)?

A) 0.57
B) 1.75
C) 67
D) 2800

Question 59

Which of the following are true of the force against which the left ventricle must pump?
1) Referred to as left ventricular afterload.
2) Equivalent to systemic vascular resistance.
3) Helps to determine left ventricular stroke volume.

A)1 and 3 only
B)1 and 2 only
C)1, 2, and 3
D)2 and 3 only

Question 60

Which of the following would have a negative impact on cardiac contractility?
1) Acidosis
2) Digitalis
3) Hypoxia
4) Norepinephrine

A)1, 2, and 3
B)2 and 4 only
C)4 only
D)1 and 3 only

Question 61

What is the role of the dense connective tissue termed annulus fibrosi cordis in the function of the heart?

A) Provides an anchoring structure for the heart valves, and also electrically isolates the atria from the ventricle.
B) Allows the blood to enter the left atrium from the right atrium before birth.
C) Pulls in the right ventricular wall, aiding its contraction.
D) Separate the right and left ventricles.

Question 62

What is a potential cause of cardiac tamponade?

A) A large pericardial effusion
B) Blockage of the left ventricle
C) Excessive amount of fluid the pleural space
D) Clots in the superior vena cava

Question 63

The dicrotic notch recorded in the aorta immediately follows what mechanical event of the cardiac cycle?

A) Closure of the aortic valve
B) Closure of the atrioventricular valves
C) Isovolume contraction
D) Opening of the aortic valve

Question 64

An abnormal amount of fluid can accumulate between the layers of the pericardium resulting in which of the following?

A) Pericardial effusion
B) Pulmonary embolism
C) Atrial fibrillation
D) Premature ventricular contractions

Question 65

During the later stages of ventricular relaxation, the pressures in their chambers drop below those in the atria. This results in which of the following?
1) Rapid drop in atrial pressures
2) Opening of the atrioventricular valves
3) Rapid ventricular filling
4) V pressure wave

A)2 and 3 only
B)1 and 2 only
C)1, 2, 3, and 4
D)2, 3, and 4 only

Question 66

What is the cause of a myocardial infarction?

A) Decreased perfusion to the pulmonary artery
B) Partial or complete obstruction of a coronary artery
C) Blockage in one or more of the great vessels
D) Narrowing of part of the aorta

Question 67

The second heart sound is associated with what mechanical event of the cardiac cycle?

A) Atrioventricular valve closure
B) Atrioventricular valve opening
C) Semilunar valve closure
D) Semilunar valve opening

Question 68

What is the role of the left and right ventricles?

A) Supply the body with blood.
B) Increase the concentration of red blood cells in the blood.
C) The forward movement of the blood.
D) Draining of blood into the right atrium.