Cardio And Resp During Exercise - Week 16

Question 1

What determines the strength of muscle fibres?

Answer 1

Cross sectional area of fibres proportional to strength

Question 2

Features of slow twitch muscle fibres?

Answer 2

Oxidative
Red
Prolonged endurance activity

Question 3

What are features of fast twitch fibres?

Answer 3

Type 2a
Red
Endurance or rapid force
Quickly fatigue

Question 4

Features of the fast twitch muscle fibres?

Answer 4

Type 2B
White
Rapid force production
Quickly fatigue

Question 5

What is isometric contraction?

Answer 5

Contraction against resistance
Length of muscle stays the same

Question 6

What is isotonic contraction?

Answer 6

Contraction against resistance where length of muscle changes

Concentric - in direction of contraction (joint angle decreases)
Eccentric - opposite direction of contraction (joint angle increases)

Question 7

What does endurance training enable?

Answer 7

Increased mitochondrial function
Hypoxia inducing factors
Increased Hb conc

Question 8

What happens during intense short term exercise?

Answer 8

10-15s —> creatine phosphate, ATP
Up to 2 mins —> glycogen to glucose-6-phosphate
Several mins —> lactic acid build up, oxygen debt, 2L O2 to replenish ATP and creatine phosphate

Question 9

What is recovery phase features?

Answer 9

Fast component - resting levels of ATP and CP resorted

Slow component - lactic acid converted to glucose in liver
Lactic acid converted to pyruvic acid

Question 10

What is the role of respiratory system during exercise?

Answer 10

Meet increased o2 demand
Increase ventilation rate
Increase tidal volume

Question 11

What happens if vo2max is exceeded in exercise?

Answer 11

Lactic acid accumulation

Question 12

What factors alter vo2max?

Answer 12

Age
Sex
Activity

Question 13

What causes cardiac output to increase?

Answer 13

Increased heart sympathetic activity —> increased stroke volume (ventricular myocardium) and HR (SA node)

Decreased heart parasympathetic activity —> increased HR (SA node)

Question 14

What results in stroke volume increasing?

Answer 14

Increased venous return —> increased end-diastolic volume
increased sympathetic activity —> increased contractility

Also decreased arterial pressure (after load)

Question 15

What is stroke volume?

Answer 15

Amount of blood expelled by heart in each beat

Question 16

How does central venous pressure and total peripheral resistance change to increase stroke volume?

Answer 16

CVP - changes diastolic filling pressure
TPR - changes ability to expel blood into arterial system

Question 17

Benefits of exercise and reducing CVD?

Answer 17

Reduces BP
increased circulating HDL and reduced triglycerides
Arterial wall homeostatic changes
Increased hair tic function
Reduced calcification
Increased ventricular chamber wall thickness