Contraction Strength of muscle fibres Flashcards
1
Q
Definition of Motor unit
A
The Motor neurone and the fibres it intervenes
2
Q
Neural control of muscular contraction
A
- CNS sends impulses to muscles (action potential)
- The strength and frequency determines the quantity of muscle that contracts, and the speed in which it contracts
- When the AP threshold of a muscle is reached by Impulses, chemical processes occur at the neuromuscular junction and muscle fibres contract
- When the CNS reduces/ stops frequency and strength of impulses, the action potential will drop below the required threshold, and the fibres will cease contracting
3
Q
Definition of Wave Summation
A
Where there is a repeated nerve impulses with no time to relax, so a smooth, sustained contraction occurs, rather than twitches
4
Q
Definition of Spatial Summation
A
When the strength of a contraction changes by altering the number and size of the muscles motor unit
5
Q
How to increase the strength of contraction
A
Wave Summation
Spatial Summation
6
Q
Tetanic contraction
A
A sustained muscle contraction caused by a series of fast repeating stimuli
7
Q
What is the All or None Law
A
The muscle fibre can only be contracting or not
