Question

All or none law is not applicable for

• A. Whole skeletal muscle
• B. Single skeletal muscle
• C. Whole cardiac muscle
• D. Single smooth muscle fibre

Answer 1

The correct option is A Whole skeletal muscle

All or none law is the principle that states that the strength by which a muscle fiber responds to a stimulus is independent of the strength of the stimulus. If that stimulus exceeds the threshold potential, the muscle fiber will give a complete response, otherwise, there is no response.

Each muscle fiber is innervated by each nerve terminal or a nerve terminal innervates 2 or 3 muscle fibers. So their response is not related to others. The all or none law is seen is single fibers of skeletal muscles and smooth muscles but not the whole fiber. Whereas the cardiac muscle innervation is continuous and the whole muscle act as a single unit. So the whole cardiac muscle is applicable to all or none law.

So the correct option is A.