What is the functional role of the T tubules?
A) synthesize ATP to provide energy for muscle contraction
B) enhance cellular communication during muscle contraction
C) stabilize the G and F actin
D) hold cross bridges in place in a resting muscle

Question

Quizplus · Accepted Answer

T tubules (transverse tubules) are invaginations of the sarcolemma (membrane of muscle fibers) that penetrate deep into the cell. They are important for enhancing cellular communication during muscle contraction by allowing action potentials (electrical signals) to rapidly spread deep into the muscle fiber, triggering the release of calcium ions from the sarcoplasmic reticulum (an organelle in muscle cells) and ultimately leading to muscle contraction. T tubules therefore play a crucial role in coordinating the contraction of the entire muscle fiber.

What Is the Functional Role of the T Tubules