Question

Increasing axon diameter decreases membrane and intracellular resistance, so it seems the two might cancel each other out in terms of their effect on the conduction speed. Yet, conduction speed is increased by increasing diameter size. Why?

A. Membrane resistance doesn't really affect conduction speed that much.
B. Intracellular resistances doesn't really affect conduction speed that much.
C. Membrane resistance decreases linearly while intracellular resistance decreases by the square of the radius.
D. Intracellular resistance decreases linearly while membrane resistance decreases by the square of the radius.

Answer 1

The diameter of an axon influences the conduction speed of an action potential. Increasing the diameter increases conduction speed. The resistance posed by the membrane and intracellular components is not as significant in determining conduction speed.

Step-by-step explanation:

The conduction speed of an action potential along an axon is influenced by the diameter of the axon. When the diameter of the axon increases, the conduction speed also increases. This is because a wider axon allows for faster spread of depolarization, similar to how water flows faster in a wider river compared to a narrow creek. The resistance posed by the membrane and intracellular components of the axon is less significant in determining conduction speed, compared to the influence of axon diameter.