MUSCLE RECRUITMENT Flashcards
1
Q
What is a motor neurone?
A
- specialised cells which transmit nerve impulses rapidly to a group of muscle fibres. The motor neurone and its muscle fibres are termed as motor unit.
2
Q
What is the all or none law?
A
- depending on whether the stimulus is above threshold, all the muscle fibres will give either a complete contraction or no contraction at all.
3
Q
what is the strength of the muscular contraction dependent on?
A
- number of motor units
4
Q
Describe some characteristics of slow oxidative muscle fibres?
A
- high capillary density
- high mitochondria density
- high myoglobin density
- Low phosphocreatine stores
- slow speed of contraction
- high fatigue resistance
- For endurance athletes.
5
Q
List characteristics for fast twitch fibres IIa.
A
- high capillary density
- moderate mitochondria density
- moderate myoglobin density
- high phosphocreatine stores
- fast speed of contraction
- moderate fatigue resistance
- high intensity athletes
6
Q
List characteristics for fast glycolic twitch fibres IIx
A
- low capillary density
- low mitochondria density
- low myoglobin density
- high phosphocreatine stores
- fast speed of contraction
- low fatigue resistance
- explosive power athletes
7
Q
what is recruitment?
A
- the process of increasing the number of active motor units to produce increasing levels of muscle contraction
8
Q
what is the size principle of recruitment?
A
- during recruitment small, medium, and the large motor units are used in order during a contraction to increase force
9
Q
What is summation?
A
- the additive effect of sequential activation when the contractile response of the first activation is still present as the following contractile response occurs.
10
Q
What is titanic contraction?
A
- the contractile response that occurs when repetitive stimulation with a frequency that is high enough results in incomplete relaxation between activation.
11
Q
which muscle fiber type tends to atrophy first?
A
Type 1 ore than type 2
