# Muscle Twitch --- A **muscle twitch** is one contraction of a [[skeletal muscle|muscle fiber]]. **Tetany** is when muscles don't get a chance to relax between twitchs. Skeletal muscles experience tetany but cardiac muscles do not. That would be a bad time ![[skeletal vs cardiac muscle twitch.png]] ## Skeletal Muscle Twitch **Skeletal muscle twitches** are initiated by a signal from a [[neurons|motor neuron]] ## Cardiac Muscle Twitch Cardiac muscle cells cannot experience **tetany** because the the **refractory** preiod of their action potentials is juast about as long as it takes for the **muscle twitch** to occur ___