Neuromuscular System

Question 1

What does it mean to exercise aerobically?

Answer 1

Exercising with oxygen. It usually occurs when the intensity of exercise is low and the demand for oxygen can be met.

Question 2

What does it mean to exercise anaerobically?

Answer 2

Exercising without oxygen. The intensity of exercise is high and the demand by the muscles for oxygen can not be met.

Question 3

Give 3 characteristics of slow twitch fibres.

Answer 3

1. Slow contraction speed.
2. Low fatigue ability
3. High aerobic capacity

Question 4

A marathon runner would use what type of muscle fibres?

Answer 4

Slow twitch

Question 5

Give 3 characteristics of fast oxidative glycolytic fibres?

Answer 5

1. Fast contraction speed
2. Medium fatigue ability
3. Medium aerobic capacity.

Question 6

What muscle fibres would a 200m runner use?

Answer 6

Fast oxidative glycolytic fibres (Type IIA)

Question 7

Give 3 characteristics of fast glycolytic fibres?

Answer 7

1. Fastest contraction speed
2. High fatigue ability
3. Low aerobic capacity

Question 8

A 100m sprinter or a smash in tennis would require which type of muscle fibres?

Answer 8

Fast glycolytic (Type IIB)

Question 9

What is hypertrophy?

Answer 9

When a muscle becomes bigger and stronger

Question 10

What is a motor unit made up of?

Answer 10

A motor neurone and muscle fibres

Question 11

Define what a motor neurone is.

Answer 11

Nerve cells that transmit instructions from the brain as electrical impulses to the muscles

Question 12

What is the neuromuscular junction?

Answer 12

Where the motor neurone and muscle fibre meets.

Question 13

What type of movement would a small motor unit carry out?

Answer 13

Fine movements

Question 14

What type of movement would a large motor unit carry out?

Answer 14

Gross movements

Question 15

What does the all or none law say?

Answer 15

When a motor unit sends an impulse to the muscle, either all the muscle fibres have to contract or none of them do- muscle fibres can’t partially contract.

Question 16

How does wave summation increase the strength of a contraction?

Answer 16

This is when impulses are sent by the motor neurone to the muscle very frequently. There is no time for the muscle to relax and so there is a smooth and sustained contraction.

Question 17

How does tetanic contraction increase the strength of contraction?

Answer 17

When impulses are frequently sent by the motor neurone to the muscle, calcium builds up. Because there is no time for the muscle to relax the calcium is just continually built up and so there is a smooth, forceful and sustained contraction.

Question 18

Why would an athlete use spatial summation?

Answer 18

To change the strength of their contraction by changing the number and size of the motor units they are using. By recruiting more and bigger motor units the athlete can develop a contraction with more force.

Question 19

What does a muscle spindle do?

Answer 19

Detects how far and fast a muscle is being stretched. It can produce a stretch reflex as a result of this.

Question 20

When does a Golgi tendon organ be activated?

Answer 20

When there is tension in a muscle.

Question 21

What does the stretch reflex do?

Answer 21

Causes the muscle to contract and prevents over stretching and reduces the risk of injury.

Question 22

What role do muscle spindles play in PNF?

Answer 22

They detect overstretching as athlete pushes muscle as far back as possible and begins initiating stretch reflex.

Question 23

What is autogenic inhibition?

Answer 23

This is when there is a sudden relaxation in the muscles response to high tension (after being held as far as possible for a long time) and it cancels the stretch reflex.