MICROANATOMY

Detailed explanation-1: -Muscles of the body receive signals (stimuli) from brain. Excitability of muscles signifies how quickly they respond to stimuli. Quicker the response, more will be the excitability of muscles.

Detailed explanation-2: -( muscles can only pull, never push.) Excitability is the ability to respond to a stimulus, which may be delivered from a motor neuron or a hormone. Extensibility is the ability of a muscle to be stretched or extended. Elasticity is the ability to a muscle to return to its original length when relaxed.

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: -Excitability, also termed responsiveness, is the ability of a cell to receive and respond to a stimulus by changing its membrane potential. In the case of muscle, the stimu-lus is usually a chemical-for example, a neurotransmitter released by a nerve cell.