CVR 33

Question 1

How is the SNS activated in exercise?

Answer 1

psychic - hypothalamus, frontal lobes

Irradiation - corticospinal tracts to medullary cardio regulating centres

Ergoreceptors, jiont receptors

Question 2

Whats the maximum CO for a normal person

Answer 2

25-30 L/min

Question 3

Why is 02 extracted easier during exercise from the blood

Answer 3

diffusion distance smaller

Diffusion gradient increased

Increased exchange in cap bed

Bigger Bohr effect

More 2-3 BPG

Question 4

How is arterial blood gas level so tightly controlled?

Answer 4

Fast - central command, chemoreceptor, joints and blood K+

Slow - C02 production, lactic acid, temperature

Question 5

Why does diffusion capacity increase in exercise?

Answer 5

increased by 3 times due to increase CO and pulmonary art gas pressure improving V/Q ratio

Question 6

V02 max of a trained athlete

Answer 6

60ml/min/kg

Question 7

How is oxygen debt defined

Answer 7

V02 in excess of resting V02 after exercise

Question 8

What are the effects of training?

Answer 8

increase in glycolytic and oxidative capacity

increase in cap density

increase muscle fibre diameter

Bigger V02 max VE max CO max

Lower resting heart rate bigger stroke volume

bigger 02 debt threshold

Question 9

What is not affected by rest

Answer 9

V02 at rest
Diffusing capacity
maximum heart rate
CO at rest
Haemoglobin conc.