Neuromuscular System

Question 1

Which muscle fibre type is used for high intensity exercise

Answer 1

Fast-twitch - type II (x and a)

Question 2

Which muscle fibre types are used for endurance exercise?

Answer 2

Slow-twitch type I

Question 3

3 characteristics of Slow-twitch muscle fibres?

Answer 3

Slow contraction speed.
Small motor neurone size.
Slow Motor neurone conduction capacity.
Low Force produced.
Low Fatiguability.
High Mitochondrial density.
High Myoglobin content.
High Capillary density.
Very High Aerobic capacity.
Low Anaerobic capacity.
Low Myosin ATPase activity.
Low Glycogen stores.
Low PC stores

Question 4

3 characteristics of Fast twitch type IIx Fibres?

Answer 4

Fast contraction speed.
Large motor neurone size.
Fast motor neurone conduction capacity.
High Force produced.
High Fatiguability.
Low Mitochondrial density.
Low Myoglobin content.
Low Capillary density.
Low Aerobic capacity.
Very high Anaerobic capacity.
Very high Myosin ATPase/glycolytic enzyme activity.
High Glycogen stores.
High PC stores.

Question 5

What is the All-Or-None Law?

Answer 5

Once a motor neurone stimulates the muscle fibres either all of them contract maximally or none of them do.

Question 6

What is Wave Summation?

Answer 6

Repeated activation of a motor neurone stimulating a given muscle fibres either results in a greater force of contraction.

Question 7

What do Muscle Spindles do?

Answer 7

Muscle Spindles detect a change in length of the muscles and how fast they do so.
They provide impulses to the nervous system which send impulses back to the muscles, causing them to contract and so prevent overstretching.

Question 8

What does the Golgi Tendon do?

Answer 8

They detect an increase in muscle tension, and send impulses to the brain to prevent the stretch reflex, which allows the muscle to relax and lengthen.