Remember wave forms!!!
Equilibrium calculated by Nernst equ. (aka Nernst equilibrium)
Goldman equ. Determines potential given all ions and permeability for each
Amplitude will decay exponentially with distance from stimulus site
λ (length constant) determines strength of action response
Sub threshold responses result of small λ and do not result in action potentials
Higher K channel threshold results in longer action potential
Rapid repolarization determined by experiment mapping potential with Na-free bath
Conductance
Na
Rapid onset
Rapid offset
K
Slow onset
Slow offset
After hyperpolarization
Refractory period
Absolute refractory period
Na channel???
Myelin and gaps of Ranvier propagate action potentials by blocking large sections of an axon from being exposed to extracellular ions
MS (multiple sclerosis)
Immune system believe to attack myelin proteins
Increases capacitance, decreases resistance thus reducing voltage