Physiology 3120 Lecture Notes - Lecture 6: Resting Potential, Action Potential, Myelin
3 Jan 2018
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Document Summary
Excitable cells (like nerve cells and muscle cells) are capable of generating electrochemical impulses at their membranes. Cell body has dendrites which receives the input from the presynaptic nerve. The action potential: occur incredible fast (3-4 ms but in heart can be up to 300ms) 70mv the resting membrane potential calculated by the: took into account permeability and charge. The action potential (ap) is a rapid reversal of the resting membrane potential: changing the membrane potential during an ap requires changing the permeability of the membrane to ions and not changing concentration gradient) Threshold: the membrane potential at which an ap is initiated (-55mv) Depolarization: when the membrane potential becomes more positive (-70 -60 mv) Repolarization: return of membrane potential back to the. Hyperpolarization: when the membrane potential is more negative than the rmp (eg. -90 mv) Changes in the membrane potential require changes in membrane permeability requires special protein channels.
