Membrane_potential_10.2 - -Vm= Sum of Ex of all ions-Na/K...

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Membrane potential -Separation of electrical charge that exists across the plasma membrane due to distribution of ions and charged molecules -Most cells are more negative inside -electrochemical gradients -net gradients= concentration and electrical -could be in same (NA+) or opposite directions (K+) -If opposite, one will dominate -Vm= voltage across membrane -voltage gradient -most cells at rest= -70mV -Membrane permeability -increase permeability ions move -movement= Current= Change in Vm -Ex= Equilibrium potential -voltage at which electrical and chemical gradients for an ion are balanced
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Unformatted text preview: -Vm= Sum of Ex of all ions-Na/K pump-Establishes concentration and electrical gradients-ion pump and ion channels balanced at Vm Graded potentials-Change in permeability change in membrane potential ( ∆ Vm)-generates electrical signals-local change in ion flow-confined to small region of plasma membrane-magnitude is variable-cell is polarized at rest-depolarized= negativity-hyperpolarized= negativity-repolarized= to rest-Characteristics-stimulatory vs inhibitory-response related to stimulus strength-signal diminishes with distance...
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This note was uploaded on 04/22/2008 for the course EEOB 232 taught by Professor Bronson during the Spring '07 term at Ohio State.

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