PHYSIOL 335 Chapter Notes - Chapter 6: Resting Potential, Nernst Equation, Extracellular Fluid
9 Sep 2016
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Charges of the same type repel each other (opposites attract) Lipid layers of the plasma membrane are insulators: separates the intracellular and extracellular fluid. Inside of cell is negatively charged with respect to outside. Outside of cell is positively charged with respect to inside: both of these are referred to as the resting membrane potential, resting membrane potential = -70mv. Majority of the intracellular and extracellular fluid is electrically neutral (just the membrane has a charge: na+, k+, cl- are in the highest concentrations in cells. Na+ and cl- are in higher concentrations outside of the cell. Na+/k+ pump: helps to establish the membrane potential. Pump moves 3na+ into the cell for each k+ it pumps out. Contributes to negative inside of cell membrane and positive outside cell membrane: sets up the concentration gradient for na+ and k, electrogenic pump: Some ion channels are gated (opened or closed) under certain conditions.
