An action potential rapidly spreads to the central portions of a muscle cell by means of

Question

Quizplus · Accepted Answer

The T tubules are the invaginations of the sarcolemma that allow for the rapid spread of the action potential to the central portions of the muscle cell, where it triggers the release of calcium ions from the sarcoplasmic reticulum and initiates muscle contraction. Z lines are the boundaries between sarcomeres, and lateral sacs are another term for terminal cisternae, which are part of the sarcoplasmic reticulum.

An Action Potential Rapidly Spreads to the Central Portions of a Muscle