Muscles That Are Skin Deep

What am I looking at?

This image is a stained cross section taken under polarized light through the skin and subcutaneous muscles (that is, muscles just under the skin) of a rabbit. The outer layers of skin are the green, yellow, brown, and red layers at the top of the image (1). The subcutaneous muscle is the scaly pattern of light blue and gray at the bottom of the image (2).

Biology in the background

Rabbits have very thin, delicate skin that is covered with a fine layer of fur and supported by a layer of muscle underneath the skin. The epidermis (the outermost layer of skin) is thought to be only one or two cells thick – much thinner than human skin. The muscles underneath and incorporated into the skin form into bundles that allow the rabbit to move its skin and hair, helping it avoid skin injuries.

However, if their skin is damaged, rabbits have a much higher rate of skin cell turnover than humans do. This high proliferation rate helps rabbits replace damaged cells more quickly than other mammals can.

The epidermis of a rabbit is only about 40 micrometers thick, or roughly half as thick as a human hair.

Technique

This image was created using polarized light and a form of light microscopy called darkfield illumination.