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Unformatted text preview: 11-12-07 anatomy notes1.Muscular Systema.Excitation of Skeletal Muscle-Neurogenic (must receive a stimulus, it doesnt contract on its own)i.Neuromuscular (myoneural junction)1.Componentsa.Axon Terminal (End Foot)-synaptic knobi.Axon (fiber)-severalb.Synaptic Clefti.Spacec.End Platei.Specialized portion of sarcolemmaii.Sequence of Events for Stimulation (nerve impulse-beginning point)-the whole sequence takes 3 milliseconds (maybe)1.Action potential passes down an axonthat splits into many end feet2.Calcium ions enter an end foota.AP reaches end footb.Ca enters end foot3.End foot releases acetylcholine (ACh) into synaptic clefta.ACh in spherical vesiclesb.Ca stimulates ACh release by exocytosis4.ACh diffuses across the synaptic cleft to receptors on the end plate (muscle cell membrane)5.Action potential initiated in muscle cell membrane6.Action potential goes down each T-tubule and into the sarcoplasm NEXT to lateral sacs of the sarcoplasmic reticulum7.Lateral sacs release calcium ions into myofibrils of muscle...
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