mechanism of the stimulation of contraction

• What is the first step in the mechanis, that causes the stimulation of a muscle contraction?

  Action potentials arriving at the end of the axon open calcium ion channels in the membrane. calcium ions flood into the end of the axon.
• What is the second step in the mechanism that causes the stimulation of muscles?

  Vesicles of Acetylcholine move towards and fuse with the end membrane.
• What is the third step in the mechanism which causes the sti8mulation of a muscle contraction?

  Acetylcholine molecules diffuse across the gap and fuse with receptors in the sarcolemma
• What is the fourth step in the mechanism which causes the stimulation of a muscle contraction?

  The fusing of acetylcholine with receptors in the sarcolemma causes sodium ion channels to open that allow sodium ions to enter the muscle fibre that depolarise the sarcolemma
• What is the last step in the 'mechanism which results in the stimulation of contraction?

  A wave of depolarisation spreads along the sarcolemma and down transverse tubules into the muscle fibre.