Skeletal Muscle Under The Microscope 🔬

Skeletal muscle as the name suggests are mainly muscles around/attached to your bones via tendons. We have three types of muscles in our body, skeletal, smooth and cardiac muscle. When I first looked at all three types under the microscope back in school, all three were very different. As in you could see the difference very easily. However comparing my notes to the slides I have here, it doesn’t seem as though my slides are very good examples.

Below are my drawings and notes from back then.

The skeletal muscle fibres (longitudinal) are much longer and appear wave like, flowing towards the same direction. A few of the nuclei are bunched closely in a straight line. White lines, connective tissue can be seen in between the fibres. The transverse skeletal muscle on the other hand appears to be sectioned off in an oval shape with the nuclei on the edges. The fibres are dot like with connective tissue within them but not in any particular shape, which is different to the longitudinal cut.

I actually have two slides of skeletal muscle tissue. Neither one of them appear to have wave like fibres. They do have nuclei bunched together closely in a straight line with connective tissue in between (white line).

Unfortunately I do not have a cross-section of the skeletal muscle, even though one of the slides was marked as both long and cross section. But a cross section shows bundles of muscle fibres being held together with connective tissue.

It also looks like a nice marbled piece of steak. Lol.
Don’t believe me?
Let me see if I can find a photo online…..here we go…. check out the marbling... don't we look tasty? lol

Source

Ok back to the slides, here are the two microscopic views of the skeletal muscle long-section.

The person who prepped the below slide didn’t do the best job.
But we can see still the details.

Skeletal muscle also differs from the smooth & cardiac muscle by the fact that it moves voluntarily; whereas smooth muscle and cardiac muscle are involuntary muscles. Meaning you can control skeletal muscle at your own will whereas cardiac & smooth muscles you cannot.