Exercise Physiology Chapter 9 Test Bank - UARK

the primary purpose of the cardiovascular system

deliver adequate levels of oxygen and remove wastes from body tissues

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

an increase in cardiac output and a redistribution of blood flow form inactive tissues to skeletal muscles

all gas exchange between the vascular system and tissues occurs in

capillaries

backflow of blood form the arteries into the heart ventricles is prevented by the

semilunar valves

the muscle of the heart is referred to as the

myocardium

electrical impulses are conducted between heart muscle cells by

intercalated discs

the contraction phase of the heart is called

systole

in a healthy heart, the time spent in systole is generally ____________ diastole

shorter than

during exercise, the time spent in diastole and systole

is decreased, with the greatest decrease occurring in diastole

the difference between systolic and diastolic blood pressure is called the

pulse pressure

the normal pacemaker of the heart is the

Sinoatrial node

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

T wave

withdrawal of parasympathetic influence of the heart results in

an increase in heart rate

the cardiovascular control center is located in the

medulla oblongata

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

Frank-Starling Law of the Heart

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

both an increase in mean arterial pressure and a decrease in vascular resistance

the most important variable that determines resistance blood flow is

the diameter of the blood vessel

the relationship between cardiac output and metabolic rate is

linear and positively correlated

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

40% of Vo2 max

the age dependent decrease in maximal heart rate can be estimated via the karvonen formula

HR max = 220-age (years)

autoregulation of blood flow to contracting muscles during exercise is due to

locally produced factors such as nitric oxide, prostaglandins, and adenosine

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

the increase in systolic blood pressure

sympatholysis refers to

local inhibition of sympathetic-induced vasoconstriciton

a local increase in the nitric oxide concentration around arterioles would result in

vasodilation

the arterial-venous oxygen difference

increases as a function of exercise intensity

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

Fick Equation

the metabolic demand of the heart can be estimated by

1) the rate-pressure product

2) the double product

3) multiplying heart rate by systolic blood pressure

the greatest resistance to blood flow is in the

arterioles

the central command theory of cardiovascular control proposes that initial signal to the cardiovascular control centers comes from

higher brain centers

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

the bundle branches depolarize, the ventricle contracts, the ventricular pressure increases, and blood exists the ventricle

which of the following most accurately describes changes in autonomic control of heart rate during incremental exercise (from rest to VO2 max)?

PNS withdrawal is followed by SNS outflow

which of the following factors can decrease blood pressure?

systemic vasodilation

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

both muscles are composed of striated fibers containing actin and myosin

which of the following is NOT a mechanism for increasing venous return during exercise?

an increase in stroke volume

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?

blood flows through the aorta, oxygen moves out of the capillaries, blood flows through the venules, blood enters the veins

atrial repolarization occurs during which phase of the cardiac cycle as observed on an ECG?

the QRS complex

according to the Fick equation, if cardiac output doubles during exercise and the arterial-mixed venous oxygen difference remains constant, body oxygen consumption would

increase by 100%

which of the following statements about beta-adrenergic blocking medications are true?

1) beta blocking drugs reduce heart rate during exercise

2) beta blockages reduces the vigor of ventricular contraction

3) beta blocking drugs compete with epinephrine and norepinephrine for beta-adrenergic receptors in the heart

which of the following factors contribute to "fine-tuning" of cardiovascular control during exercise?

1) muscle chemoreceptors

2) baroreceptors

3) muscle mechanoreceptors

Which of the following factors has the greatest influence on blood flow to a skeletal muscle during exercise?

diameter of the arterial blood vessels leading to the muscle

Which of the following statements about heart rate variability (HRV) is NOT true?

HRV decreases in response to regular aerobic exercise training.

If a person with ischemic heart disease experiences chest pain when their double product exceeds 20,000, which of the following combinations will produce angina?

HR = 150, BP = 150/80

Which of the following would not result in an increase in stroke volume during exercise?

an increase in afterload

In the transition from rest to exercise, what is the distribution of cardiac output to the heart?

the % of cardiac output is unchanged, but the volume of blood increases