PNB 2XB3 Chapter Notes - Chapter 2: Lamellar Corpuscle, Pyramidal Cell, Threshold Potential
23 Sep 2018
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Pnb 2xb3 chapter 2: electrical signals of nerve cells. Of current used to evoke it: ex. larger currents do not elicit larger. Ap: all-or-none ap occur fully or not at all. Let neurons conduct signals over long distances despite poor passive electric axon properties: current above threshold ap of constant amplitude across axon w/o decay (active conduction, wire let passive current flow long distances (1000s) Anesthesia and neuronal electrical signaling: anesthetics drugs that produce anesthesia, anesthesia reduces sensation in surgery to stop pain/ create unconsciousness, 1. Regional desensitizes larger body region: local anesthetics injected near spinal cord, patients stay conscious, ex. injected in epidural space of spinal canal to stop pelvic labor pain. Enhance postsynaptic gaba receptor activity at inhibitor synapses. Strong synaptic inhibition reduces neuronal activity causing sleep. Class 1 (barbiturates like pentobarbital): are addictive, lethal at high doses. Benzodiapenes like diazepam/valium/zolpidem/ambien is a hypnotic agent for sleep. Propofol also blocks na+ channels: 3.
