Chapter Seven : Acute Responses to Exercise

Question 1

Acute responses definition

Answer 1

An immediate change in the respiratory, cardiovascular and/or muscular system in response to exercise

Question 2

Respiratory acute responses

Answer 2

Respiratory rate
Tidal volume
Ventilation
Diffusion

Question 3

Cardiovascular acute responses

Answer 3

O2 consumption
a-VO2 difference
Cardiac output
Venous return
Blood pressure 
Redistribution of blood flow

Question 4

Muscular acute responses

Answer 4

Temperature
Motor unit recruitment
Energy substrates
Lactate

Question 5

Ventilation definition

Answer 5

How much air is breathed in or out in one minute (L/min)

Question 6

Ventilation during exercise

Answer 6

Increases during exercise as tidal volume and respiratory rate increase
At submax intensity, ventilation will increase linearly
At max intensity, ventilation will increase until the exercise is stopped

Question 7

Ventilation equation

Answer 7

Tidal volume (L/breath) X Respiratory Rate (brreaths/min)

Question 8

Tidal volume definition

Answer 8

How much air is inspired or expired in one breath

Question 9

Respiratory rate definition

Answer 9

The number of breaths taken in one minute

Question 10

Ventilatory threshold

Answer 10

The point where ventilation is no longer increasingly linearly with the exercise intensity. Occurs at 65-75 % of max O2 consumption

Question 11

Diffusion in at the alveoli

Answer 11

O2 concentration in the lungs is high so it diffuses into the bloodstream
CO2 concentration in the bloodstream is high so it diffuses into the alveoli

Question 12

Diffusion at the muscle

Answer 12

O2 concentration is high in the blood stream so it diffuses into the muscle
CO2 concentration is high in the muscle so it diffuses into the blood

Question 13

Diffusion during exercise

Answer 13

The surface area of the alveoli and the muscle increase so more O2 and CO2 can be exchanged increasing rate of diffusion

Question 14

Cardiac Output definition

Answer 14

The amount of blood pumped out of the heart in one minute (L/min)

Question 15

Cardiac output equation

Answer 15

Cardiac output (Q) = Heart Rate X Stroke volume

Question 16

Heart rate definiton

Answer 16

The number of times the heart beats in one minute (bpm)

Question 17

Stroke volume definition

Answer 17

The amount of blood ejected from the left ventricle per beat (L/beat)

Question 18

Cardiac output during exercise

Answer 18

Increases as exercise intensity increases
Stroke volume increases as there are stronger contractions of the heart, reaches a maximum
Heart rate increases until the max is reached which is 220-age
A trained athlete has a larger SV than an untrained athlete

Question 19

VO2 definition

Answer 19

Is the volume of oxygen that can be taken up and used by the body

Question 20

VO2 during exercise

Answer 20

As exercise intensity increases so does O2 consumption

Question 21

a-VO2 difference

Answer 21

The difference in O2 concentration in the arterioles compared to the venules; a measure of how much O2 the muscles are extracting from the blood

Question 22

a-VO2 difference during exercise

Answer 22

As exercise intensity increases the working muscles extract greater amounts of O2 from the blood, increasing the a-VO2 difference. It can reach 100%

Question 23

Venous return definition

Answer 23

The flow of blood back to the heart

Question 24

Venous return during exercise

Answer 24

The heart can only eject how much blood it had in its ventricles so venous return increases to return more blood to the heart
During exercise the venous return is increased via the muscle pump, respiratory pump and venoconstriction, and one-way valves

Question 25

Venous return muscle pump

Answer 25

When the muscles contract they squash the veins pushing the blood back up to the heart, the blood catches in the valves

Question 26

Venous return respiratory pump

Answer 26

During expiration the veins filled with blood to be pushed up, respiratory rate increases making the pump more effective

Question 27

Venous return venoconstriction

Answer 27

When the veins constrict pushing the blood towards the heart, reflex action

Question 28

Blood volume during exercise

Answer 28

During aerobic exercise, blood volumes decrease depending on intensity, environmental factors (temp) and level of hydration Due to the fluid loss from sweat, decreases blood plasma

Question 29

Redistribution of blood flow during exercise

Answer 29

At rest 80% of blood is directed to the brain and internal organs At submaximal intensity 50-60% is directed to the working muscles During max intensity 80% is directed to the working muscles Arteries vasoconstrict to the areas not needing blood Arteries vasodilate to the areas needing blood

Question 30

Redistribution of blood flow

Answer 30

Provides O2 and fuels needed for energy production and to remove waste products from working muscles

Question 31

Blood pressure during exercise

Answer 31

Increase in cardiac output increases blood pressure Both the systolic and diastolic blood pressure can increase, systolic increases more in exercise Aerobic exercise causes a rise, however higher intensity increases it more

Question 32

Systolic blood pressure definition

Answer 32

Pressure in the arteries following contraction of ventricles as blood is pumped out of the heart

Question 33

Diastolic blood pressure definition

Answer 33

The pressure in the arteries when the heart relaxes and ventricles fill with blood

Question 34

Diastole definition

Answer 34

The relaxation phase of the heartbeat

Question 35

Systole definition

Answer 35

The contraction phase of the heartbeat

Question 36

Increased blood flow during exercise (muscular responses)

Answer 36

The skeletal capillaries open up to allow increase in total muscle blood flow, deliver large blood volume with min increase in blood flow velocity and increase surface area to increase diffusion rates

Question 37

Recruitment and activation of muscle fibres during exercise

Answer 37

During exercise the brain signals to increase the amount of motor units used Smaller, slower twitch fibres that are slower to contract are recruited first then the largest fast twitch fibres are recruited

Question 38

Motor unit principle

Answer 38

When a motor unit is activated it will contract maximally or not at all

Question 39

Motor unit definition

Answer 39

A motor neuron and the muscle fibres it stimulates

Question 40

Energy substrates during exercise

Answer 40

ATP is used up really quickly Glycogen is then used All fuel substrates decrease within the muscles as they are used up

Question 41

Lactate during exercise

Answer 41

Lactate remains stable being removed through oxidation until the lactate inflection point is reached and then the lactate increases quickly, unable to be removed and causing fatigue

Question 42

Body temp during exercise

Answer 42

Heat is a by-product of converting chemical to electrical energy Sweat glands activate and the blood flow increases to the skin allowing heat to be released through the skin