LIFESCI 2C03 Lecture Notes - Myotonia, Channelopathy, Rate Equation
10 Apr 2012
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Document Summary
Is at -70mv, and is observed in a giant axon of a squid. 4 things that keep the resting membrane potential are: The capacitor charge of the membrane (negative inside, positive outside) Passive osmotic gradient (things want to go from a. The sodium/potassium pump uses 40-50% of energy and pushes out 3 na+ ions and pulls in 2 k+ ions. Ouabain is a plant toxin that inhibits the na/k pump allowing more sodium-> more calcium in the body which helps heart contraction. Action potential is initiated when the sodium ion channels are opened and allow sodium to enter the cell. Voltage-gated (the channel opens when a specific voltage of electrical stimulus. Large diameters axons are very important for quick propulsion to escape danger. The axons of a squid are 400 times the diameter of mammalian axons. In squids the axoplasm can be easily squeezed out and replaced by fluid of interest.
