Question

Describe the two factors that influence the rate of impulse propagation?

Answer 1

The two main factors are insulation by the myelin sheath and the diameter of the axon.

• The presence of the myelin sheath forces the signal to jump from one node of ranvier to the other. This is called saltatory conduction, and this jumping instead of ''walking'' along the axon makes the speed of conduction high.

• For the diameter, it was discovered that the higher the diameter the faster the signal goes. This is may be due to less resistance to movement of the ions in and out along the axon.