When a muscle fiber receives an action potential from a neuron, how many sarcomeres in the fiber contract?

Question

Quizplus · Accepted Answer

When a muscle fiber receives an action potential from a neuron, all of the sarcomeres in the fiber contract. This is known as the all-or-nothing principle of muscle contraction, where the entire muscle fiber contracts completely or not at all. The strength of the stimulus determines the frequency and number of action potentials sent to the muscle fiber, but does not affect the number of sarcomeres that contract.

When a Muscle Fiber Receives an Action Potential from a Neuron