BIOL 207 Lecture Notes - Lecture 21: Neuromuscular Junction, Esterase, Choline
26 Nov 2016
School
Department
Course
Professor
Document Summary
Sliding filament mechanism is last part of process. The sequence of events by which electrical or excitation at nmj (neuromuscular junction) of the sarcolemma leads to and is coupled with the contraction of muscle fiber and its subsequent relaxation. Triated (cid:373)us(cid:272)le (cid:272)ells do(cid:374)"t (cid:272)o(cid:374)tra(cid:272)t automatically on own( all need nervous stimulation which is excited before contraction) Motor neurons innervate muscles or glands b/c bring about movement/activity. Afferent neurons neurons go to spinal cord. All striated muscle have these (secrete acetylcholine) Made up of 2 chemicals acetyl and choline. If ach stays for extended time muscle will always be stimulated leads to it (cid:271)ei(cid:374)g destroyed and loses function (chemicals split) Ase break down of ester bonds. Esterase breaks bond and ach loses ability to stimulate muscle cell: junctional fold located on wavy lines, found in neuromuscular junction, have receptors on them, ach receptors found on tip of junctional fold. Only region on muscle cell where ligand gated receptors respond to ach.
