Question

In a circuit model of nerve-impulse propagation, what would happen to the propagation speed if the myalin sheath thickness were larger?

Answer 1

A larger myelin sheath thickness would result in an increase in the propagation speed of the nerve impulse.

Step-by-step explanation:

The speed of propagation of an action potential in a nerve cell depends on the diameter of the axon and the myelin sheath. A larger myelin sheath thickness would result in an increase in the propagation speed of the nerve impulse. The myelin sheath acts as an insulator that prevents current from leaving the axon, allowing the action potential to travel faster along the axon. For example, in myelinated axons, the action potential jumps from one node of Ranvier to the next, a process known as saltatory conduction. This allows the action potential to propagate quickly, skipping the myelinated regions where the membrane potential is not regenerated. Therefore, if the myelin sheath thickness were larger, the action potential would propagate at a faster speed.