A muscle is bundles inside bundles inside bundles — each wrapped in its own connective tissue sheath. Zoom in from the whole muscle down to the tiny unit that actually shortens: the sarcomere.
Whole muscle
Whole musclezoom in, level by level
Zoom the levels
📷 Reference image
A real labeled figure to compare with the interactive above.
Muscle Organization — OpenStax, CC BY 4.0 (via Wikimedia Commons)
