• The I bands, which are the "light" bands formed by the sections of the sarcomere that contain only actin, and would only be seen in a relaxed muscle. Once a muscle contracts, the sarcomere shortens, and the actin filaments slide together, making the light I bands virtually disappear. This leaves only the dark A bands visible, so that an electron micrograph of a contracted muscle consists of mostly dark bands.

Copyright 2023, Wired Ivy, LLC

Answerbag | Terms of Service | Privacy Policy