MUSCLE PHYSIOLOGY

Detailed explanation-1: -The all-or-none law is the principle that the strength by which a nerve or muscle fiber responds to a stimulus is independent of the strength of the stimulus. If that stimulus exceeds the threshold potential, the nerve or muscle fiber will give a complete response; otherwise, there is no response.

Detailed explanation-2: -The ‘All or None’ Law Each fibre within a motor unit contracts according to the all or none law. This principle states that when a motor unit receives a stimulus of sufficient intensity to bring forth a response, all the muscle fibres within the unit will contract at the same time, and to the maximum possible extent.

Detailed explanation-3: -A twitch occurs when one muscle fiber contracts in response to a command (stimulus) by the nervous system. The time between the activation of a motor neuron until the muscle contraction occurs is called the lag phase (sometimes called the latent phase).

Detailed explanation-4: -Each muscle fiber contracts on an “all or nothing” principle; a muscle fiber either contracts fully or not at all, and all the fibers in a single motor unit contract at the same time. When a muscle is required to contract during exercise, not all motor units are contracted at the same time.