Question

question 31
what is the function of transverse tubules?
a transmit a muscle impulse into the cell interior
b the storage of sodium ions for the action potential at the cell surface
c the storage of calcium ions
d the place where actin and myosin interact

Explanation:

Transverse tubules (T - tubules) are invaginations of the muscle cell membrane (sarcolemma). They are crucial for transmitting the muscle impulse (action potential) from the cell surface (sarcolemma) deep into the cell interior. This ensures that the impulse reaches the sarcoplasmic reticulum (which stores calcium ions) simultaneously throughout the muscle fiber, allowing for coordinated muscle contraction.

• Option B: Sodium ions for action potential at the cell surface mainly move through ion channels in the sarcolemma, not stored in transverse tubules.
• Option C: The storage of calcium ions is the function of the sarcoplasmic reticulum, not transverse tubules.
• Option D: The interaction of actin and myosin occurs at the sarcomere (the basic unit of muscle contraction), not in transverse tubules.

Answer:

A. transmit a muscle impulse into the cell interior