Where does this come from, and can I check it?

Myosin heads grab actin, pull, release and repeat to shorten each sarcomere. The figure is taken from NIGMS, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a human body fact?

Yes. It sits on the Human Body shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

What else can I read about it?

The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

Mondo Knows Facts

Muscles shorten as two protein filaments slide

Myosin heads grab actin, pull, release and repeat to shorten each sarcomere Each sarcomere holds thick myosin filaments between thinner actin filaments. Myosin heads attach to actin, pivot to drag it inward, then detach using energy from ATP. Because the filaments themselves do not shorten, the sarcomere and the whole muscle fibre get shorter as they overlap more. It sits in Mondo's human body collection, one of 200 facts that each trace back to the reference below.

Where this comes from

NIGMS

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

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Science trivia

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Tags: muscles, proteins, contraction

Muscles shorten as two protein filaments slide: the short answers

Where does this come from, and can I check it?: Myosin heads grab actin, pull, release and repeat to shorten each sarcomere. The figure is taken from NIGMS, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a human body fact?: Yes. It sits on the Human Body shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.