The mechanism responsible for the size principle is that compared to large motor neurons,
A)small motor neurons have a small surface area and are easier to depolarize.
B)small motor neurons have a larger (more negative)membrane potential.
C)small motor neurons do not respond to IPSPs
D)all of the above answers are correct

Question

Quizplus · Accepted Answer

The size principle states that smaller motor neurons are recruited first before larger motor neurons. This is because small motor neurons have a smaller surface area and therefore are easier to depolarize. As more force is needed, larger motor neurons with a larger surface area are recruited. The other answer choices, (B) and (C), are not accurate mechanisms for the size principle.

The Mechanism Responsible for the Size Principle Is That Compared