Don’t be Squamish
Skin’s top layer is a prototypical “squamous epithelium”: it contains layers of densely packed epithelial cells that form continuous sheets. The sheets stack up on top of each other, and then the whole stack sits on a basement membrane, which supports the epithelial and serves as a source of new cells for growth and regeneration. Epithelia have nerves but no blood vessels.
Epithelia are classified by the shape of the top cells. For the skin epidermis, these cells have a “polygon” shape when viewed from above, and thus, the epidermis is called a “squamous epithelium.”
Image: Here cultured epithelial cells are imaged via multiphoton microscopy, illustrating the classic polygon shape of “squamous epithelial cells.” Cell nuclei were stained for DNA using Hoechst 33342 (cyan), the Golgi apparatus expres targeted GFP (green), and actin was stained using fluorescent phalloidin (magenta).