When the current reached the following stages, what proportion of fibers in the muscle were contracting? a) at threshold b) at the maximal stimulus c) above the maximal stimulus

A) few B) 100% c) 100%

Explanation:

Muscle responds a stimulus which is capable of generating action potential. Muscle response is in a way of "ALL or NONE". Muscle response to greater stimulus by recruiting more muscle fibers.

A) At threshold there would be only a small proportion of muscle is contracting.

B) At maximal stimulus the maximum number (100%) of recruitable fibers are contrating.

C) The number of recruitable fibers can't increase above maximal stimulus because already the maximum number of recruitable fibers are contracting.