Which of the following characteristics of an axon is most dependent on its diameter?
A. The magnitude of its resting potentialB. The duration of its refractory potential
C. The conduction velocity of its action potential
D. The overshoot of its action potential
The Answer is .C.
The
conduction velocity of an action potential along an axon is proportional to the
axon’s diameter for both unmyelinated and myelinated axons. The resting
membrane potential, the duration of the relative refractory period and the
magnitude of the action potential are dependent on the type and density of
electrically excitable gates and the ability of the Na to establish and
maintain the concentration gradients. These characteristics are not related in
any systematic way to the axon diameter.
