when does the striated muscle contract
when it receives an impulse from a motor neurone via the neuromuscular junction
contraction of a striated muscle (1)
when an impulse travelling along the axon of a motor neurone arrives at the presynaptic membrane the action potential causes calcium ions to diffuse into the neurone
contraction of a striated muscle (2)
this stimulates vesicles conatining the neurotransmitter Acetylcholine (ACh) to fuse with the presynaptic membrane
contraction of a striated muscle (3)
the released ACh diffuses across the neuromuscular junction and binds to receptor proteins on the sarcolemma
contraction of a striated muscle (4)
ion channels in the sarcolemma are stimulated to open allowing sodium ions to diffuse in