Topic 9

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Created by: rfraser96
Created on: 18-04-17 17:20

At what exercise intensity is fatigue likely to be due to glycogen depletion? (1 mark)

70-75% VO2 max ???

1 of 7

Describe a possible mechanism of fatigue in the heat. (4 marks)

Cycling to exhaustion at 60 % VO2 max in the heat (40 °C) ???

2 of 7

Why does dehydration cause a reduction in stroke volume? (1 mark)

It reduces plasma volume making blood thicker, less venous return and left ventricular filling?

3 of 7

What cardiovascular changes occur with progressive dehydration?

Increased heart volume, decreased stroke volume, decreased cardiac output, increased a-v O2 difference

4 of 7

What neurotransmitter is thought to play a role in central fatigue? (1 mark)

Serotonin (promotes sleep and tiredness)

5 of 7

Describe how serotonin production may be increased in rest. (8 marks)

5-HT is made from TRP, an amino acid available in plasma. Its bound to albumin, as are fatty acids. They cross the blood-brain barrier by specific transporter and BCAA utilise same transporter as TRP

6 of 7

Describe how serotonin production may be increased in prolonged exercise. (8 marks)

The increase in fatty acids during exercise displace the TRP from albumin. There is now an increase in free TRP. There is an increase in muscle uptake of BCAA so an increase in f-TRP/BCAA. Increase in TRP entry to brain and increased 5-HT production

7 of 7

Other cards in this set

Card 2

Front

Describe a possible mechanism of fatigue in the heat. (4 marks)

Back

Cycling to exhaustion at 60 % VO2 max in the heat (40 °C) ???

Card 3

Front

Why does dehydration cause a reduction in stroke volume? (1 mark)

Back

Card 4

Front

What cardiovascular changes occur with progressive dehydration?

Back

Card 5

Front

What neurotransmitter is thought to play a role in central fatigue? (1 mark)

Back

View more cards

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Topic 9