Which organelle is primarily associated with forming channels along the T-tubules in muscle cells to facilitate the transmission of action potentials?

• A. Lysosomes
• B. Sarcoplasmic reticulum
• C. Golgi apparatus
• D. Mitochondria

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the role of T-tubules in muscle cells. T-tubules (transverse tubules) are invaginations of the sarcolemma (muscle cell membrane) that help transmit action potentials deep into the muscle fiber.
2. Step 2: Recognize the function of the sarcoplasmic reticulum (SR). The SR is a specialized organelle in muscle cells responsible for storing and releasing calcium ions, which are essential for muscle contraction.
3. Step 3: Learn how the sarcoplasmic reticulum interacts with T-tubules. The SR forms terminal cisternae that are closely associated with T-tubules, creating a structure called a triad. This arrangement facilitates the transmission of action potentials from the T-tubules to the SR, triggering calcium release.
4. Step 4: Eliminate the incorrect options. Lysosomes are involved in cellular digestion, Golgi apparatus is responsible for protein modification and transport, and mitochondria generate ATP. None of these organelles are directly involved in forming channels along T-tubules or transmitting action potentials.
5. Step 5: Conclude that the sarcoplasmic reticulum is the organelle primarily associated with forming channels along the T-tubules to facilitate the transmission of action potentials in muscle cells.