The action potential traveling along the t-tubule is detected by the
A) ryanodine receptor.
B) dihydropyridine (DHP) receptor (L-type calcium channel).
C) acetylcholine receptor.
D) Ca²⁺ ATPase.

Question

Quizplus · Accepted Answer

The dihydropyridine (DHP) receptor (L-type calcium channel) is the voltage sensor that detects the action potential traveling along the t-tubule. This conformational change in the DHP receptor then causes the nearby ryanodine receptors on the sarcoplasmic reticulum to open and release calcium ions into the cytoplasm, triggering muscle contraction. Acetylcholine receptor and Ca²⁺ ATPase are not involved in this process.

The Action Potential Traveling Along the T-Tubule Is Detected by the