PE- Neuromuscular Junctions (DONUGHUE)

Question 1

What is the synaptic cleft?

Answer 1

Small gap

Question 2

What is a motor unit?

Answer 2

Made up of motor neutrons and muscle fibres

Question 3

Describe the ‘all or none law’:

Answer 3

Nerve impulse initiated in the motor neuron cell
Nerve impulse conducted down the axon of the motor neuron by a nerve action potential to the synaptic cleft
Neurotransmitter called acetylcholine is secreted into the synaptic cleft to conduct the nerve impulse across the gap
If the electrical charge is above a threshold, the muscle fibre will contract
This happens in an ‘all-or-none’ fashion