Passive properties of axonal membranes.

Space(Length) constant

Time constant

(they are only reflections of the physical properites of the neuronal membrane. Not directly dependant on metabolism or any voltage-dependant permeability changes.)

λ= √(R_md)/(R_l4)

R_m= membrane resistance(inversely proportional to permeability)

d= diameter of axon

R_l= longitudinal resistance

Distance it takes for depolarizing displacement to decay by 65% of it's initial value.

τ= R_mC_m

R_m= membrane resistance.(inversly proportional to permeability)

C_m= membrane capacitance that describes the ability of the membrane to store charge.

Electrotonic Conduction

Conduction velocity is proportional to the diameter of the axon.

The larger the diameter o fthe axon, the greater the speed of propagation.

Saltatory Conduction

The velocity of propagation is determined by the distance between the Nodes of Ranvier.

The greater the distance between the nodes, the greater the velocity of an action potential propagation.