Summation.

Question 1

Define Motor Unit.

Answer 1

A motor unit is a motor neurone and the fibres it attaches to.

Question 2

Describe a Motor Unit.

Answer 2

All fibres in a Motor Unit are the same type.
A whole muscle is made up of multiple motor units. Proportions of slow and fast depend on genetics.

Question 3

Define Spatial Summation.

Answer 3

Controlling the size, number and type of motor units recruited.
To do with the ‘adding up’ of impulses from multiple motor units.

Question 4

Explain Spatial Summation in terms with Low Force.

Answer 4

A few small, Slow Twitch Units.

Question 5

Explain Spatial Summation in terms with High Force.

Answer 5

A lot of big, Fast Twitch Units.

Question 6

Define Wave Summation.

Answer 6

Controlling the frequency of impulses sent along a motor neurone.
To do with the time between impulses.

Question 7

Define Tetanic Contraction.

Answer 7

Impulse at max frequency, smooth and consistent.
The slower the impulse, the lower the force.