The function of the T tubules in muscle contraction is to a. make and store glycogen, b. release Ca²⁺ into the cell interior and then pick it up again, c. transmit the action potential deep into the muscle cells, d. form proteins.

Verified step by step guidance

1. Identify the role of T tubules in muscle cells.
2. Understand that T tubules are extensions of the cell membrane that penetrate into the center of skeletal and cardiac muscle cells.
3. Recognize that T tubules are involved in transmitting the action potential from the surface of the muscle cell to its interior.
4. Consider how the action potential triggers the release of calcium ions from the sarcoplasmic reticulum, which is crucial for muscle contraction.
5. Conclude that the primary function of T tubules is to transmit the action potential deep into the muscle cells, facilitating the contraction process.

Key Concepts

T Tubules

T tubules, or transverse tubules, are extensions of the muscle cell membrane that penetrate into the muscle fiber. They play a crucial role in conducting electrical impulses, or action potentials, from the surface of the muscle cell deep into its interior, ensuring that the entire muscle fiber contracts simultaneously.

Action Potential

An action potential is a rapid change in the electrical charge across a cell membrane, which occurs when a neuron or muscle cell is stimulated. In muscle contraction, the action potential travels along the T tubules, triggering the release of calcium ions from the sarcoplasmic reticulum, which is essential for muscle contraction.

Calcium Ions (Ca²⁺)

Calcium ions (Ca²⁺) are vital signaling molecules in muscle contraction. When the action potential reaches the T tubules, it stimulates the release of Ca²⁺ from the sarcoplasmic reticulum into the cytoplasm, initiating the interaction between actin and myosin filaments, which leads to muscle contraction.