14. Pick up a heavy object in concentric Biceps flexion. Now lower and straighten your arm. You should feel your Biceps contracted but Triceps relaxed. That an eccentric contraction of the Biceps This just shows how complex movement can be!
25. Cross Bridge Cycle If electron micrographs of a relaxed and contracted myofibril are compared it can be seen that: • These show that each sarcomere gets shorter when the muscle contracts, so the whole muscle gets shorter. • But the dark band, which represents the thick filament, does not change in length. • This shows that the filaments don’t contract themselves, but instead they slide past each other.
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