Muscle: Skeletal Muscle

Skeletal muscle: moves joints by strong and rapid contractions.
Each muscle is a bundle of muscle fibres, each of which is a long multinucleated cell.

Single mononucleated cells called myoblasts fuse together to form this multinucleated fibre (myotube) during development. This process also occurs to regenerate muscle fibres.

(Click here to find out about how muscles regenerate)

If you cut a muscle longitudinally and stain it (H&E), then you can see long muscle fibres, that look stripy. Have a look at this H&E stained section and notice the stripes.

The stripes come from the repeating sarcomeres. Find out what a muscle sarcomere is.

The dark purple nuclei can be seen on the edges of the muscle fibres.

photo of skeletal muscle TS

This picture shows a transverse section through skeletal muscle.

If you cut a muscle transversely, like this, then you can see the roughly circular outline of the individual muscle fibres.