The contraction cycle is triggered by the rise in ________ released from the sarcoplasmic reticulum (SR).
A) Na⁺
B) K⁺
C) Ca²⁺

Question

Quizplus · Accepted Answer

The rise in Ca²⁺ triggers the contraction cycle by binding to troponin and allowing myosin to bind to actin, initiating the power stroke. Na⁺ and K⁺ are not specifically involved in muscle contraction, although they do play a role in membrane potential and action potential generation.

The Contraction Cycle Is Triggered by the Rise in ________