Essentials of Exercise: Chapter 5 - Physiology of Training

Question 1

To meet the increaseed demands of muscle during exercise, what two major adjustments in blood flow mus occur?

Answer 1

Increase in Cardiac Output and a redistribution of blood from inactive organs to the active skeletal muscle.

Question 2

Cardiac Output

Answer 2

The amount of blood pumped by the heart per minute; usually expressed in liters of blood per minute.

Question 3

Heart Rate (HR)

Answer 3

The number of heart beats per minute.

Question 4

Stroke Volume (SV)

Answer 4

The amount of blood pumped from the left ventricle of the heart with each beat.

Question 5

What is the equation for Cardiac Output

Answer 5

Heart Rate x Stroke Volume

Question 6

Sinoatrial Node (SA node)

Answer 6

A group of specialized myocardial cells, located in the wall of the right atrium, that controls the heart’s rate of contraction; the “pacemaker” of the heart.

Question 7

What are the two most prominent factors that influence heart rate?

Answer 7

The parasympathetic and sympathetic divisions of the autonomic nervous system.

Question 8

Autonomic Nervous System

Answer 8

The part of the nervous system that regulates involuntary body functions, including the activity of the cardiac muscle, smooth muscles, and glands.

Question 9

Depolarize

Answer 9

To decrease decrease the electrical potential across a membrane, as when the inside of a neuron becomes less negative to the outside.

Question 10

Repolarize

Answer 10

To restore the difference in charge between the inside and outside of the plasma membrane of the muscle fiber or cell following depolarization.

Question 11

Atrioventricular Node (AV node)

Answer 11

The specialized mass of conducting cells in the heart located at the atrioventricular junction.

Question 12

Vagus Nerves

Answer 12

The tenth cranial nerve; parasympathetic, general sensory nerve.

Question 13

Acetylcholine

Answer 13

A white crystalline neurotransmitter and derivative of choline that is released at the ends of nerve fibers in the somatic and parasympathetic nervous systems and is involved in the transmission of nerve impulses in the body.

Question 14

Cardiac Accelerator Nerves

Answer 14

Part of the sympathetic nervous system that stimulates the SA node to increase heart rate.

Question 15

Catecholamine

Answer 15

Hormone (e.g., epinephrine and nor-epinephrine) released as part of the sympathetic response to exercise.

Question 16

Epinephrine

Answer 16

A hormone released as part of the sympathetic response to exercise; also called adrenaline.

Question 17

Norepinephrine

Answer 17

A hormone release as part of the sympathetic response to exercise.

Question 18

Diastolic Blood Pressure (DBP)

Answer 18

The pressure in the arteries during the relaxation phase of the cardiac cycle; indicative of total peripheral resistance.

Question 19

Diastole

Answer 19

The period of filling of the heart between contractions; resting phase of the heart.

Question 20

Frank-Starling Mechanism

Answer 20

The mechanism by which an increased amount of blood in the ventricle places a stretch on the cardiac muscle fibers, thereby causing a stringer ventricular contraction to increase the amount of blood ejected.

Question 21

Vasoconstriction

Answer 21

Narrowing of the opening of blood vessels (notably the smaller arterioles) caused by contraction of the smooth muscle lining the vessels.

Question 22

Vasodialation

Answer 22

Increase in diameter of the blood vessels, especially dilation of arterioles leading to increased blood flow to a part of the body.

Question 23

Autoregulation

Answer 23

Local control of blood distribution (through validation) in response to a tissue’s changing metabolic needs.

Question 24

Viscera

Answer 24

The collective internal organs of the abdominal cavity.

Question 25

Parasympathetic Nervous System

Answer 25

A subdivision of the autonomic nervous system that is involved in regulating the routine functions of the body, such as heart beat, digestion, and sleeping.

Stimulates digestive secretions, slows the heart, constricts the pupils, dilates blood vessels.

Question 26

Sympathetic Nervous System

Answer 26

Responsible for mobilizing the body’s energy and resources during times of stress and arousal.

Reduces digestive secretions, speeds the heart, contracts blood vessels.

Question 27

Systolic Blood Pressure (SBP)

Answer 27

The pressure exerted by the blood on the vessel walls during ventricular contraction.

Question 28

What factors contribute to Systolic Blood Pressure increase during exercise?

Answer 28

1. Increased heart contractility and stroke volume increase the force with which blood leaves the heart.
2. Muscle action requires greater force or pressure to deliver blood into the exercising muscles.
3. Vasodilation within the exercising muscles allows more blood to drain from the arteries through the arterioles and into the muscle capillaries, thus minimizing changes in diastolic pressure.