Question

Which statement about T-tubules in muscle fibers is true?

a) They carry genetic information
b) They store excess ATP
c) T-tubules carry the action potential through the sarcoplasm
d) They help in cellular respiration

Answer 1

T-tubules in muscle fibers carry the action potential through the sarcoplasm, triggering muscle contraction.

Step-by-step explanation:

T-tubules in muscle fibers carry the action potential through the sarcoplasm. They are invaginations in the sarcolemma that allow the propagation of an action potential along the sarcolemma and into the interior of the cell. The T-tubules trigger the opening of calcium channels in the adjacent sarcoplasmic reticulum, causing calcium ions to diffuse out of the sarcoplasmic reticulum and into the sarcoplasm, which initiates muscle contraction.