How a Muscle Contracts · Muscles
Filaments don't shorten — they slide past each other.
Here's the counter-intuitive part: when a muscle contracts, nothing inside it actually gets shorter. The filaments stay exactly the same length — they just slide further past each other, so the ends are pulled closer together.
There's more: filaments don't shorten — they slide past each other. The full explanation — and the interactive version you can tap and quiz yourself on — lives in the app.
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