Neuromuscular Revision Flashcards
List 3 structural characteristics of a type 1 muscle fibre
Size of the motor unit = small
Mitochondria density = high
Capillary density = high
List 3 structural characteristics of a type 2a muscle fibre
Size of the motor neuron = medium
Mitochondria density = high
Capillary density = intermediate
List 3 structural characteristics of a type 2x muscle fibre
Size of the motor neuron = very large
Mitochondria density = low
Capillary density = low
List 3 functional characteristics of a type 1 muscle fibre
Contraction time = slow
Resistance to fatigue is high
Power produced = low
List 3 functional characteristics of a type 2a muscle fibre
Contraction time = moderately fast
Resistance to fatigue = fairly high
Power produced = medium
List 3 functional characteristics of a type 2x muscle fibre
Contraction time = very fast
Resistance to fatigue = low
Power produced = very high
Explain the all or non law
Individual muscle fibres within a motor unit contract fully or not at all
In order to activate these muscle fibres a minimum amount of stimulation is needed
What is spatial summation
Occurs when impulses are received at the same time at different place on the neuron
It is the recruitment of additional bigger motor units within a muscle to develop more force
What is wave summation and tectanic summation
The repeated activation of a motor neuron and a given muscle fibre results in a greater force of contraction
When a motor unit is stimulated many times in quick succession this produces the highest level of force called TECTANIC CONTRaCTION
What happens if a second impulse arrives at the motor unit before it has time to completely relax from the first impulse (wave summation)
The motor unit responds with a stronger contraction as the effect of the second impulse is added to the first
