Deck 10: Circulatory Responses to Exercise

Question 1

The contraction phase of the heart is called

A) diastole.
B) atrial contraction.
C) systole.
D) the cardiac cycle.

Answer 1

C

Question 2

The fact that an increase in end-diastolic ventricular volume increases the stroke volume of the heart is an illustration of the

A) influence of the parasympathetic nervous system on cardiac output.
B) Frank-Starling law of the heart.
C) influence of atrioventricular node on cardiac output.
D) influence of blood pressure on cardiac output.

Answer 2

B

Question 3

The __________ represents ventricular repolarization during a recording of the electrical activity (i.e., ECG) of the heart.

A) P wave
B) QRS complex
C) T wave
D) R wave

Answer 3

C

Question 4

An increase in parasympathetic outflow to the heart results in

A) an increase in HR.
B) a decrease in HR.
C) a slight increase in arterial blood pressure.
D) a slight decrease in arterial blood pressure followed by an increase in HR.

Question 5

The relationship between cardiac output and metabolic rate is

A) linear.
B) curvilinear.
C) exponential.
D) there is no relationship between cardiac output and metabolic rate.

Question 6

All gas exchange between the vascular system and tissues occurs in

A) venules.
B) capillaries.
C) arterioles.
D) veins.

Question 7

The increase in cardiac output that occurs during exercise is due to

A) both an increase in mean arterial pressure and a decrease in vascular resistance.
B) a decrease in vascular resistance only.
C) an increase in mean arterial blood pressure only.
D) an increase in heart rate and a decrease in mean arterial blood pressure.

Question 8

The difference between systolic and diastolic blood pressure is called the

A) pulse pressure.
B) mean arterial blood pressure.
C) brachial pressure.
D) double product.

Question 9

The muscle of the heart is referred to as the

A) pericardium.
B) myocardium.
C) epicardium.
D) endocardium.

Question 10

The primary purpose of the cardiovascular system is to

A) convey heat away from deep body tissues.
B) deliver adequate amounts of oxygen and remove wastes from body tissues.
C) serve as a buffer fluid for metabolic wastes during exercise.
D) circulate oxygenated blood to the lungs.

Question 11

In order to meet the increased oxygen demands of muscle during exercise, two major adjustments in blood flow must be made:

A) an increase in HR and blood pressure.
B) an increase in brain blood flow and blood flow to the skin.
C) an increase in cardiac output and a redistribution of blood flow from inactive tissues to skeletal muscles.
D) an increase in muscle blood flow and an increase in blood flow to the liver.

Question 12

Which of the following is a mechanism for increasing venous return during exercise?

A) an increase in stroke volume
B) venoconstriction
C) an increase in HR
D) a decrease in blood pressure

Question 13

The normal pacemaker of the heart is the

A) atrioventricular node.
B) sinoatrial node.
C) AV node.
D) SV node.

Question 14

The cardiovascular control center is located in the

A) medulla oblongata.
B) carotid sinus.
C) cerebrum.
D) atria of the heart.

Question 15

Electrical impulses are conducted between heart muscle cells by

A) intercalated discs.
B) intermediate junctions.
C) minute synapses of the sympathetic nervous system.
D) Purkinje fibers.

Question 16

In a healthy heart, the time spent in systole is generally

A) longer than diastole.
B) equal to diastole.
C) shorter than diastole.
D) three times longer than diastole.

Question 17

Skeletal and cardiac muscle are similar in which of the following ways?

A) both muscles contain type I, IIa, and IIx fibers
B) both muscles are under voluntary control
C) both muscles contain fibers that are branched
D) both muscles are composed of striated fibers containing actin and myosin

Question 18

The most important variable that determines resistance to blood flow is

A) the viscosity of blood.
B) the length of the blood vessel.
C) the diameter of the vessel.
D) blood pressure.

Question 19

Backflow of blood from the arteries into the ventricles is prevented by the

A) semilunar valves.
B) bicuspid valve.
C) atrioventricular valves.
D) coronary valves.

Question 20

During exercise, the time spent in diastole and systole

A) remains unchanged.
B) is decreased equally.
C) is decreased, with the greatest decrease occurring in diastole.
D) is increased.

Question 21

At any end-diastolic volume, stroke volume is increased by parasympathetic stimulation.

Question 22

In order to maintain systemic blood flow, an increase in peripheral resistance would require an increase in blood pressure.

Question 23

The greatest resistance to blood flow is in the

A) veins.
B) arterioles.
C) aorta.
D) capillaries.

Question 24

At any level of oxygen consumption, heart rate and blood pressure are lower during leg work when compared with arm work.

Question 25

Autoregulation of local blood flow is due to

A) the withdrawal of sympathetic impulses to arterioles.
B) an increase in parasympathetic outflow to arterioles.
C) local factors such as a decrease in PO₂, an increase in PCO₂, and potassium concentrations.
D) an increase in sympathetic impulses to arterioles.

Question 26

The central command theory of cardiovascular control states that the initial signal to the cardiovascular system at the beginning of exercise comes from higher brain centers.

Question 27

A local increase in the adenosine concentration around arterioles would result in

A) vasoconstriction.
B) no change in vessel diameter.
C) vasodilation.

Question 28

The metabolic demand of the heart can be estimated by

A) the rate-pressure product.
B) the double product.
C) multiplying heart rate by systolic blood pressure.
D) all of the above.

Question 29

Most of the increase in mean arterial blood pressure that occurs during dynamic (isotonic) incremental exercise is due to

A) an increase in diastolic blood pressure.
B) the increase in systolic blood pressure.
C) both an increase in diastolic and systolic blood pressure.
D) none of the above.

Question 30

Which of the following is the correct order of events pertaining to contraction of the left ventricle?

A) The bundle branches depolarize, the ventricle contracts, the ventricular pressure increases, the aortic volume increases.
B) The aortic volume increases, the ventricular pressure increases, the ventricle contracts, the bundle branches depolarize.
C) The ventricular pressure increases, the bundle branches depolarize, the aortic volume increases, the ventricle contracts.
D) The bundle branches depolarize, the ventricular pressure increases, the ventricle contracts, the aortic volume increases.

Question 31

In most subjects, stroke volume continues to increase during incremental exercise up to approximately

A) 20% of VO₂ max.
B) 40% of VO₂ max.
C) 75% of VO₂ max.
D) 90% of VO₂ max.

Question 32

Which of the following factors would serve to increase blood pressure?

A) systemic vasodilation.
B) a decrease in blood viscosity.
C) an increase in stroke volume.
D) increased parasympathetic nervous system activity.

Question 33

Which of the following is true of the heart rate change during exercise?

A) the increase in HR is due only to withdrawal of PNS influence.
B) the increase in HR is due only to increasing SNS influence.
C) the increase in HR is due only to PNS withdrawal followed by increasing SNS influence.
D) the increase in HR is due to a spontaneous increase in SA node activity.

Question 34

The relationship between oxygen uptake, cardiac output, and the arterial-venous oxygen difference is described mathematically by the

A) Hill equation.
B) Fenn equation.
C) Fick equation.
D) Frank-Starling law.

Question 35

Beta-adrenergic blocking medications

A) interfere with epinephrine and norepinephrine receptor function.
B) increase heart rate.
C) increase stroke volume.
D) inhibit the actions of acetylcholine.

Question 36

Which of the following represents the correct order of events of the flow of blood after it leaves the left ventricle and before it returns to the right atrium?

A) Blood flows through the aorta, oxygen moves out of the capillaries, blood flows though veins, blood enters the venules.
B) Blood flows through the venules, blood flows through the veins, oxygen moves out of the capillaries, blood enters the aorta.
C) Oxygen moves out of the capillaries, blood flows through the aorta, blood flows through the venules, blood enters the veins.
D) Blood flows through the aorta, oxygen moves out of the capillaries, blood flows through the venules, blood enters the veins.

Question 37

The arterial-venous oxygen difference

A) increases as a function of exercise intensity.
B) does not change during exercise.
C) decreases as the exercise intensity increases.
D) is highest during submaximal exercise.

Question 38

In general, heart rate increases in direct proportion to the metabolic rate during exercise.

Question 39

One reason the stroke volume increases during exercise is that skeletal muscle vasodilation decreases afterload.

Question 40

The decrease in maximal heart rate with age in adults can be estimated via

A) HR max = 220 - age.
B) HR max = 200 - age.
C) HR max = 210 - age.
D) HR max = 205 - age.

Question 41

An increase in cardiac output will decrease blood pressure when peripheral resistance is constant.

Question 42

Exercise training helps the heart to resist permanent damage during a heart attack.