Physiology and Pharmacology of the Neuromuscular Junction Flashcards
does the motor neurone axon divide into unmyelinated or myelinated branches?
unmyelinated
how many skeletal muscle cells does each branch of a motor neurone axon supply?
1
what is the end of a motor neurone axon called?
bouton
what is the function of a bouton?
it is the pre synaptic terminal forms a chemical synapse with the muscle membrane at the NMJ
where does the bouton synapse?
endplate region of skeletal muscle fibre
what is another name for the muscle cell membrane?
sarcolemma
what 2 things form acetylcholine
acetyl coA and choline
what enzyme is in charge of ACh synthesis?
choline acetyltransferase
how does calcium reach the pre synaptic nerve terminal?
AP causes depolarisation which promotes Ca channel opening -> Ca accesses the terminal
when will the gate of an ACh receptor open?
when 2 molecules of ACh bind to its exterior
where is ACh stored?
vesicles
what is the end plate potential?
the membrane potential generated from a higher influx of Na than efflux of K
what triggers the opening of voltage activated Na channels?
end plate potential (if large enough)
what causes the end plate potential
activated Ach receptors
what happens if the end plate potential doesn’t reach threshold?
neuromuscular transmission is blocked because no AP is generated
