What triggers the initiation of muscle contraction?

A nerve impulse and the release of calcium ions

What role do calcium ions play in muscle contraction?

Calcium ions bind to troponin, which exposes myosin binding sites on actin.

Name: How Muscles Contract
Author: Insta~Lesson

11th Grade · Science · 45 min

I can describe the steps involved in muscle contraction.

1
Muscle contraction occurs when actin and myosin filaments slide past each other, shortening the sarcomere.
2
Muscle contraction begins when a nerve impulse stimulates muscle fibers, releasing calcium ions which bind to troponin.
3
The binding of ATP severs the bonds between myosin and actin, and the energy released is stored in the myosin heads.

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