Chapter 4 - Acute Responses to Excercise

Question 1

What is an average resting heart rate?

Answer 1

70 bpm

Question 2

What is a 20 year olds maximum heart rate?

Answer 2

200 bpm

Question 3

What is stroke volume?

Answer 3

The volume of blood pumped out by the left ventricle with each beat

Question 4

What is the stroke volume at rest and during maximal exercise?

Answer 4

Rest; 60-80ml

Max: 120-130ml

Question 5

What is Cardiac ouput and what is it’s equation?

Answer 5

Volume of blood pumped out of the left ventricle per minute.
Equation: Q=SV*HR

Question 6

What is cardiac outpt at rest and during maximal exercise?

Answer 6

Rest: 4-6 L/min

Maximal Exercise: 22-24L/min

Question 7

What is venous return and through which three main mechanisms does it do so?

Answer 7

The amount of blood returning to the heart through the veins
Mechanisms: muscle pump, respiratory pump, venoconstriction

Question 8

What is Artirio-venous oxygen difference (A-VO2 diff), and what arterial and venous O2 levels can you expect during rest? What is the A-Vo2 difference and what % of it is used?

Answer 8

Rest arterial O2 concentration: 20 ml/100ml Rest venous O2 concentration: 12-15 ml/100ml Diff: 5ml/100ml
% of used O2: ~25%

Question 9

What % O2 is used in the working muscles during maximal excercise?

Answer 9

Up to 100% of the 20ml/100ml of O2 is extracted by the working muscles during max intensity exercise

Question 10

What is a persons respiratory rate during rest or moderate and maximal exercise?

Answer 10

Rest:12-15
Moderate exercise: 30-35
Maximum exercise: 48-60 (3-4*rest)

Question 11

What is a persons tidal volume (TV) and how does it change during rest and moderate and maximum intensity exercise?

Answer 11

Volume of air breathed in and out each breath
Rest: 0.5L
Moderate exercise: 2.5L
Maximum exercise; 4.0L

Question 12

What is minute ventilation? How does it change during rest and moderate and maximal exercise?

Answer 12

Volume of air breathed in each minute
Rest:6L/min
Moderate exercise: 75L/min
Maximal: 200L/min

Question 13

What is diffusion and the two sites it occur at, and how it occurs at each site?

Answer 13

The movement of molecules from areas of high concentration to areas of low concentration.
Alveolar-capillary
Increased O2 intake increases surface area of alveoli and increased Co2 levels are present in the blood due to exercise.
muscle tissue - capillary
muscles require more oxygen and capillaries surface area increases due to increased blood flow to the working muscles.

Question 14

What is Vo2 and what is it rest?

Answer 14

The amount of oxygen taken up and used each minute.

Rest: .25L/min

Question 15

How is blood redistributed during exercise and how much does the blood supply change for muscles during rest and exercise.

Answer 15

Vasodilation and vasoconstriction directs blood away from many organs toward the working muscles.
Muscle rest: 15-20%
Muscle Exercise: 80-85%

Question 16

What is the blood pressure (S/D) during rest and maximal excertion

Answer 16

Rest: 120/80
Max: 200/82

Question 17

Difference between Venoconstriction and vasoconstriction

Answer 17

Venoconstriction is the narrowing of the veins while vasoconstriction is the narrowing of the vessels (veins and arteries) in general.

Question 18

Difference between stylostic and dialostic blood pressure?

Answer 18

Stylostic: Pressure in the arteries following a hearts contraction
Dialostic: Pressure in the arteries during the relaxation phase of a hearts cycle

Question 19

How is stylostic and dialostic blood pressure effected by resistance training?

Answer 19

Stylostic: Increase
Dialostic: Increase

Question 20

Which increases blood pressure more? Aerobic or resistance training?

Answer 20

Resistance training

Question 21

How does plasma volume change during exercise?

Answer 21

decreases 10% in first 5 minutes of exercise and decreases more as person becomes dehydrated.

Question 22

What % of blood is ejected from the left ventricle at rest?

Answer 22

40-50%

Question 23

How many minutes until the stroke volume decreases during sub-maximal exercise?

Answer 23

30 minutes

Question 24

What is the two ways which muscles increase force of output?

Answer 24

• Recruitment of motor units

- Increase rate of firing of motor units

Question 25

What Is the ventilators threshold and What % of max HR does it occur?

Answer 25

• When ventilation increases at non linear rate

- occurs 65-75% of max HR

Question 26

Relationship between HR, SV and Q and maximal and sub maximal intensities:

Answer 26

HR increases linearly until max HR is reached. However SV plateaus at sub maximal intensities and therefore any increase in

Question 27

Name 4 acute respiratory responses to exercise.

Answer 27

Minute ventilation
Tidal Volume
Respiratory rate
Diffusion

Question 28

Name 9 cardiovascular responses to exercise?

Answer 28

Vo2 Heart Rate Blood flow redistribution
A-Vo2 Diff Stroke Volume
Blood Volume Cardiac Output
Blood Pressure Venous Return

Question 29

Name 6 Acute Muscular responses to exercise

Answer 29

Core Body Temperature Redistribution of blood flow
Motor Unit Recruitment Decreased energy substrate levels
Enzyme activity
Lactate Production

Question 30

What muscles contract during inspiration.

Answer 30

External?? Intercostals

Diaphragm

Question 31

List structures oxygen passes through to reach the red blood cells.

Answer 31

Alveoli - alveoli membrane - interstitial fluid - capillary membrane - plasma - red blood cells

Question 32

State the all or nothing principle.

Answer 32

Until a certain threshold is reached no muscle fibres in a motor until will contract, but once this threshold is reached all muscle fibres in the motor unit will contract maximally.