Physiology: Short Term Responses to Exercise

Question 1

Define heart rate

Answer 1

The number of times the heart beats per minute

Question 2

Define stroke volume

Answer 2

The amount of blood pumped out of the left ventricle per beat

Question 3

Define cardiac output

Answer 3

The amount of blood pumped out of the left ventricle per minute

Question 4

Outline the relationship between heart rate, stroke volume and cardiac output

Answer 4

Cardiac output = stroke volume x heart rate

Question 5

What is the cardiac output of a performer with a heart rate of 70bpm and a stroke volume of 70mls

Answer 5

4,900mls/min

Question 6

How is maximum heart rate calculated?

Answer 6

220 - age (+ or - 10)

Question 7

What does cardiac hypertrophy mean?

Answer 7

The heart gets bigger and stronger

Question 8

Who would have a lower resting heart rate - a healthy active individual or a sedentary individual? Why?

Answer 8

An active individual, as they have a higher stroke volume

Question 9

What is known as the heart’s pacemaker?

Answer 9

The SAN

Question 10

Outline the first process in the conduction of the heart and explain what it causes.

Answer 10

The SAN sends out an electrical impulse - causing the atria to contract and forcing blood into the ventricles

Question 11

Outline the role of the AVN in the conduction of the heart.

Answer 11

The AVN sends out a second nerve impulse

Question 12

In the conduction of the heart, where does the second nerve impulse get sent and what does it cause.

Answer 12

The second nerve impulse is sent down the bundle of His, causing a delay of 0.1 seconds.

Question 13

What happens to the atria in the diastolic phase?

Answer 13

It passively fills with blood.

Question 14

What happens to the ventricle in the diastolic phase?

Answer 14

It passively fills with blood

Question 15

What happens to the atria in the systolic phase?

Answer 15

It squeezes, forcing blood into the ventricles

Question 16

What happens the ventricles in the systolic phase?

Answer 16

They contract, forcing blood out of the heart

Question 17

Does the heart relax or contract in the diastolic phase?

Answer 17

Relax

Question 18

Does the heart relax or contract in the systolic phase?

Answer 18

Contract

Question 19

Define the term venous return

Answer 19

The return of blood to the heart

Question 20

How many mechanisms are there or venous return?

Answer 20

3

Question 21

Name the mechanisms of venous return

Answer 21

Muscle Pump
Respiratory Pump
One-way Valves

Question 22

Explain the muscle pump

Answer 22

Where the muscles contract, squeezing the veins and forcing blood to the heart

Question 23

Explain one-way valves

Answer 23

In the veins and prevent the back flow of blood

Question 24

Explain the respiratory pump

Answer 24

The chest size increases, which squeezes the veins and forces blood back to the heart

Question 25

Describe the 6 steps of Starling’s Law

Answer 25

During exercise, there is a greater venous return
Therefore, a greater amount of blood fills the heart
Therefore, there is a greater stretch of the walls of the heart
Therefore, their is a greater force of contraction
Therefore, there is a greater stroke volume
Therefore, their is greater amount of O2 to the working muscles

Question 26

What are the benefits of Starling’s Law?

Answer 26

A greater amount of O2 is delivered to the working muscles, so the performer can use aerobic respiration at higher intensities for longer

Question 27

What is the role of a chemoreceptor?

Answer 27

To detect changes in blood acidity levels.

Question 28

What is the role of a proprioceptor?

Answer 28

To detect muscular contractions

Question 29

What is the role of a baroreceptor?

Answer 29

To detect a change in blood pressure

Question 30

What is the role of a thermoreceptor?

Answer 30

To detect changes in body temperature

Question 31

In order to change heart rate, where do receptors send impulses to?

Answer 31

The cardiac control centre in the medulla

Question 32

The cardiac control centre in the medulla

Answer 32

Sympathetic

Question 33

To increase heart rate, which pathway does the medulla send nerve impulses down?

Answer 33

Acceleratory

Question 34

To decrease heart rate, what kind of nerve impulses does the medulla send?

Answer 34

Parasympathetic

Question 35

To decrease heart rate, which pathway does the medulla send nerve impulses down?

Answer 35

Inhibitory

Question 36

What is the redistribution of blood also known as?

Answer 36

Vascular shunting

Question 37

In order to redistribute blood, where do receptors send a nerve impulse to?

Answer 37

Vaso-motor control centre in the medulla

Question 38

To cause vaso-dilation or vaso-constriction, where does the vaso-motor control centre send impulses to?

Answer 38

The pre-capillary sphincters

Question 39

What does vaso dilation mean?

Answer 39

The blood vessels become bigger

Question 40

What does vaso constriction mean?

Answer 40

The blood vessels become smaller

Question 41

What happens to blood flow to the digestive system during exercise?

Answer 41

It decreases

Question 42

What happens to blood flow to the brain during exercise?

Answer 42

It stays the same

Question 43

What happens to blood flow to the skin during exercise?

Answer 43

It increases

Question 44

What happens to blood flow to the heart during exercise?

Answer 44

It increases