Pathway to muscle contraction

Pathway to muscle contraction

1. 1. Nerve impulse depolarizes the nerve terminal

   • 2. Votlage gated Ca2+ channels open
     • 3. Ca2+ enters the nerve terminal
       • 4. Vesicles of Ach exit the nerve terminal via exocytosis
         • 5. Ach binds to the ACh receptor at two sites of ACh receptor.
           • 6. Influx of Na+ causes depolarisation of the myocyte membrane. The Na+ enters through the ACh receptor
             • 7. This opens voltage gated Na+ and Ca2+ channels
               • 8. Then Ca2+ is realesed from SR into the cytosol of myocyte which causes muscle contraction
                 • 9. Acetylcholinesterase – anchored to the post-synaptic membrane terminates synaptic transmission