Physiology 3120 Lecture Notes - Lecture 10: Sarcomere, Biceps, Peptide
11 Aug 2016
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Alpha mn are some of the longest nerves in body, peripheral, myelinated with schwann cells. Thus when the non specific cation channels increase conductance of both na and k, k will not move but na will! Past question: what would happen if na+ and k+ gates opened at exactly the same time. Membrane potential would move to somewhere between ena+ and ek+ Because vg channels are all the way at the bottom of the synaptic folds. Now need to depolarize the lower part where the vg channels are: local currents propagate down to the bottom of the fold where vg channels are. The depolarization in that area opens the na vg channels to produce an ap just like they were produced in a neuron (same sequence of steps: aps spread out. To shut down the propagation of aps, ach is broken down by acetylcholinesterase into acetate and choline that are sent back to presynaptic axon to get recycled.
