Muscles, Part 1 - Muscle Cells: Crash Course A&P #21

We’re kicking off our exploration of muscles with a look at the complex and important relationship between actin and myosin. Your smooth, cardiac, and skeletal muscles create movement by contracting and releasing in a process called the sliding filament model. Your skeletal muscles are constructed like a rope made of bundles of protein fibers, and that the smallest strands are your actin and myosin myofilaments. Its their use of calcium and ATP that causes the binding and unbinding that makes sarcomeres contract and relax.

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Table of Contents
Smooth, Cardiac, and Skeletal Muscles Create Movement 1:18
Sliding Filament Model 4:52
Skeletal Muscles Are Made of Bundles of Protein Fibers 2:40
Actin and Myosin Myofilaments 3:54
Calcium and ATP Cause the Binding and Unbinding 5:05



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