In response to action potentials arriving from the transverse tubules, the sarcoplasmic reticulum releases
A) acetylcholine.
B) sodium ions.
C) potassium ions.
D) calcium ions.
E) acetylcholinesterase.

Question

Quizplus · Accepted Answer

Action potentials arriving from the transverse tubules of a muscle cell signal the sarcoplasmic reticulum to release calcium ions, which bind to troponin and initiate the contraction process. Acetylcholine and acetylcholinesterase are involved in the process of nerve impulses reaching the muscle cell, while sodium and potassium ions are involved in the generation of the action potential itself, but they do not directly trigger muscle contraction.

In Response to Action Potentials Arriving from the Transverse Tubules