A K K Cl Na Na Inside Outside cell ce Goldman-Hodgkin-Katz equation V= RTIn( pxlK'o+ PNa[Nalo+Pa[C 1 F(PKIK]+PNa[Na*]i+pa[CI]
Goldman-Hodgkin-Katz equation
Intracellular tulo Extracellular nuid Na+ 3 Na' K.ATPabe Role of Nat-K+ pump K o Electrogenic Hyperpolarizing Na+ Establishment of resting membrane potential: K+ Na+/K+ pump establishes concentration gradient Intracellular fluid Extracellular nuid generating a small negative + potential; pump 3Na° uses up to 40% of the atP roduced by th pI y at cell! K+
•Electrogenic •Hyperpolarizing Role of Na+-K + pump: Establishment of resting membrane potential: Na+/K+ pump establishes concentration gradient generating a small negative potential; pump uses up to 40% of the ATP produced by that cell!
Origin of the normal resting membrane potential K+ diffusion potential Na+ diffusion Na+-K+ pump
Origin of the normal resting membrane potential • K+ diffusion potential • Na+ diffusion • Na+-K+ pump
Action potential(动作电位 +50 Depolarising hase Repolarising -O phase Resting statel Undershoot Resting state -50 E-100 Time Some of the cells(excitable cells) are capable to rapidly reverse their resting membrane potential from negative resting values to slightly positive values. This transient and rapid change in membrane potential is called an action potential
Action potential（动作电位） Some of the cells (excitable cells) are capable to rapidly reverse their resting membrane potential from negative resting values to slightly positive values. This transient and rapid change in membrane potential is called an action potential
a typical neuron action potential +50 cooE Overshoot 0 Negative after- Positive potential after-potential 70 Spike potentialAfter-potential
Negative afterpotential Positive after-potential Spike potential After-potential A typical neuron action potential