NROB60H3 Chapter Notes - Chapter 4: Tetrodotoxin
22 Jan 2015
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When neuronal membrane is at rest, the voltmeter reads a steady potential difference of 65mv during the action potential the membrane potential briefly becomes positive this change happens too fast so an oscilloscope is used to study action potentials action potential has certain identifiable parts: rising phase characterized by rapid depolarization of the membrane continues until vm reaches a peak value of about 40mv part of ap where the inside of the neuron is positively charged with respect to the outside is overshoot. Membrane of fibers possess a type of gated na channel that opens when the nerve ending is stretched: thumbtack enters skin, the membrane of the nerve fibers in the skin is stretched, na+ permeable channels open, na+ ions enter the fiber through these channels because of the large concentration gradient and the negative charge of the cytosol, entry of na+ depolarizes the membrane (cytoplasmic surface (inside) of the.
