Muscle fibres - balls

Question 1

What is a motor Unit?

Answer 1

A motor neurone and all the fibres it controls

Question 2

What is the ‘all or none law’?

Answer 2

Threshold is reached
Contraction occurs in all of the fibres in the motor unit

Question 3

What is Wave Summation?

Answer 3

Muscle is stimulated again before it is relaxed
Leads to a stronger contraction

Question 4

What is a Tetanic contraction?

Answer 4

A sustained muscle contraction caused by a series of fast repeating stimuli.
All fibres stimulated to maximum contraction for high force production.

Question 5

What is Spacial summation?

Answer 5

The addition of impulses received at different places in the neuron.
Rotating the frequency of the impulse to motor units to delay fatigue (some work, some rest)

Question 6

Three ways to up the strength of contraction?

Answer 6

Larger motor units
More motor units
Fast twitch muscle fibres

Question 7

What do muscle spindles do?

Answer 7

Detect changes in muscle stretch (length)
Prevent overstretching
Done by initiating the stretch reflex

Question 8

What do golgi tendon organs do?

Answer 8

Tells you how much tension the muscle is exerting, helping to prevent overstretching

Question 9

What does PNF stand for?

Answer 9

Proprioceptive neuromuscular facilitation

Question 10

What does PNF do?

Answer 10

stretching and contracting (activation) of the muscle group being targeted in order to achieve maximum static flexibility