Answer to Question #276270 in Human Anatomy and Physiology for Water

Question

5. Why does a skeletal muscle twitch last longer  

than a skeletal muscle action potential?

Answer 1

A muscle twitch can last up to 100 ms and that of an action potential can last for 1-2ms. In muscle twitch, there is no refractory period therefore, it can be re-stimulated at any time.

A twitch occurs in three phases:

The time between the arrival of the action potential at the motor end-plate and the beginning of the contraction called the delay.

. The contraction phase where the action molecules are bound to the myosin fibres and the head of the cross-bridges turn in cycles. 

The time between the arrival of the action potential at the motor end-plate and the beginning of the contraction called the relaxation phase.