motor units Flashcards
what’s a motor unit?
a motor neuron and a number of muscle fibers
whats a motor neuron?
specialised cells that transmit nerve impulses to groups of muscle fibers
CNS
central nervous system
whats a neuromuscular junction?
where axon’s motor end plates meet muscle fibers
all or nothing law
either all the muscle fibers contract or none of them do
what happens when the nerve impulse reaches the threshold charge?
all the muscle fibers in that motor unit contract with maximal force
synaptic cleft
the space between the motor end plates and the post synaptic membrane
neurotransmitter (ACH)
transmits action potential across the synaptic cleft
(ACH)
gets secreted in the synaptic cleft to transmit the nerve impulse to the muscle fibers