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Membrane at Rest. Selectively Permeable Channels Ion Concentration Differences Nernst Relationship Ion Pumps. Reflex Loop: Sensory-to-Motor. Water. Phospholipid Bilayer. Membrane is Impermeable. Channels Allow Ions to Pass. Protein Structure. Ion Channel. Potassium Channel.
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Membrane at Rest Selectively Permeable Channels Ion Concentration Differences Nernst Relationship Ion Pumps
Nernst Relation E = 61.54 mV log10 [ion] out/ [ion]in Lets call it 60 mV
Goldman Equation Vm = 60 log10 Pk[Ko] + PNa[Nao] Pk[Kin] + PNa[Nain]
Questions • What two functions do proteins in the neural membrane perform to establish and maintain the resting membrane potential? • ON which side of the membrane are sodium ions more abundant? • When the membrane is at the potassium equilibrium potential, in which direction (in or out) is there a net movement of potassium ions? • There is much greater concentration of potassium ions inside than outside the membrane. Why, then is the resting potential negative? • When the brain is deprived of oxygen, the mitochondria within neurons cease producing ATP. What effect would this have on the membrane potential? Why?
Next Class • Chapter 4 The Action Potential