Question

All or none law is not applicable for
(A)Whole skeletal muscle
(B)Single skeletal muscle fiber
(C)Whole cardiac muscle
(D)Single smooth muscle fiber

Answer 1

Hint: All or none law is not applicable for the muscle which is a form of striated muscle tissue that is under the voluntary control of the somatic nervous system.

Complete answer:
All or none law is not applicable for Whole skeletal muscle. The law which is known as all-or-none law is the principle that tells us that the strength by using which a nerve or muscle cell will be responding to the stimulus is independent of the strength which stimulus has. If that stimulus due to some reason exceeds the threshold potential, the nerve or muscle fiber will provide a complete response; otherwise, there's no response.

Additional Information: The magnitude of the action potential which is found out in any single nerve fiber is independent of the strength of the exciting stimulus, provided the latter is adequate. An electrical stimulus below threshold strength will fail to elicit a propagated spike potential. If it's of threshold strength or over, a spike (a nervous impulse) of maximum magnitude is about up. Either the only fiber doesn't respond with spike production, or it responds to the utmost of its ability under the conditions at the instant. This basic property of the only nerve fiber is termed the all-or-none relationship. This relationship holds just for the unit of tissue; for nerve tissue, the unit is that the neuron, for striated muscle the unit is that the individual muscle cell and for the guts, the unit is that the entire auricles or the whole ventricles.
So, the correct answer is ‘Whole skeletal muscle’.

Note: A skeletal muscle is always referred to as multiple bundles known as fascicles of cells joined together called muscle fibers. The fibers and muscles are always surrounded by the connective tissue layers which are known as fasciae. Muscle fibers are formed by the fusion of developmental myoblasts, which will take place during a process which is known as myogenesis.