Question

fill in the blank question the t tubules of a muscle fiber are extensions of the and contain extracellular fluid. need help? review these concept resources. rate your confidence to submit your answer. high medium low reading © 2025 mcgraw hill. all rights reserved. privacy center terms of use

Explanation:

T - tubules are invaginations of the muscle fiber's plasma membrane. They are extensions of the sarcolemma which is the plasma membrane of muscle cells and they contain extracellular fluid. This structure is important for the rapid transmission of electrical signals in muscle contraction.

Answer:

sarcolemma