Question

In a recording of a muscle twitch, the delay between the time a stimulus is applied and the time the muscle responds is called the

A. refractory period.
B. relaxation period.
C. latent period.
D. contraction period.

Answer 1

The delay between the stimulus and muscle response in a twitch is called the latent period, which is the initial stage before muscle contraction occurs.

Step-by-step explanation:

In a recording of a muscle twitch, the delay between the time a stimulus is applied and the time the muscle responds is called the latent period.

The latent period is the initial phase in a muscle twitch following the application of a single stimulus, during which time the action potential is propagated along the sarcolemma, but muscle contraction has not yet started.

It precedes the contraction phase where Ca++ ions bind to troponin, which facilitates the movement of tropomyosin from actin-binding sites, allowing cross-bridges to form and sarcomeres to shorten resulting in muscle contraction.