BIOM20002 Lecture Notes - Lecture 13: Central Nervous System, Neuromuscular Junction, Skeletal Muscle
Document Summary
Ap in nerve ending --> ap in muscle: generation of big change in potential. Central nervous system (cns) synapse (neuron to neuron) Neuromuscular junction: synapse of a somatic motor neuron on a muscle fibre. The (cid:373)otor (cid:374)euro(cid:374)"s pres(cid:455)(cid:374)aptic a(cid:454)o(cid:374) ter(cid:373)i(cid:374)al filled (cid:449)ith s(cid:455)(cid:374)aptic (cid:448)esicles a(cid:374)d mitochondria the synaptic cleft postsynaptic membrane of the skeletal muscle fibre. Also includes extensions of schwann cells that form a thin layer covering the top of the axon. Postsynaptic side muscle cell membrane is modified into a motor end plate, a series of folds with nicotinic ach receptor (nachr) channels clustered together. Fibrous matrix of synaptic cleft has collagen fibres that hold the axon terminal and the motor end plate in proper alignment. Ach by degrading it into acetyl and choline. Neuromuscular junction: effect on target muscle is always stimulatory. Alpha motor neuron initiates ap which results in an end plate potential.
