3.3 Muscle Metabolism

Question 1

What are the 2 types of fatigue

Answer 1

Central Fatigue and Peripheral Fatigue

Question 2

Describe central fatigue

Answer 2

Fatigue within the nervous system. There is loss of excitability in the motor cortex, additionally metaboreceptors in muscles (detecting metabollic by products) give feedback further inhibiting the motor cortex.

Question 3

Describe peripheral fatigue

Answer 3

Fatigue within the muscles. It is due to failure of excitation-contraction coupling, T tubule action potential, SR calcium release etc. This causes failure of force generation at actin myosin cross bridges

Question 4

Is running out of ATP a cause of fatigue

Answer 4

No

Question 5

In times of muscle fatigue, what happens to the concentrations of ATP, inorganic phosphate and hydrogen ions

Answer 5

They increase

Question 6

In long duration exercise, describe the muscle fibres and metabolism

Answer 6

Type 1 muscle fibres using aerobic metabolism with a mix of lipids and carbohydrates

Question 7

In moderate duration exercise, describe the muscle fibres and metabolism

Answer 7

Type 1 and 2a muscle fibres using aerobic respiration with mostly carbohydrates but some lipids

Question 8

In short duration exercise, describe the muscle fibres and metabolism

Answer 8

All muscle fibres are active using both aerobic and anaerobic respiration. Carbohydrates are used for 2b fibres