Surface of the corneal epithelium

Transmission electron micrograph showing surface epithelial cells in a human cornea. Dead surface cells are about to slough away. Below the dead layer is the squamous layer, below that are the wing cells and towards the lower right are the columnar epithelial cells. A small lymphocyte is present in the layer of wing cells and can be distinguished by its small size and large nucleus. Desmosomes appear as dense concentrations on the cell membranes and function to attach adjacent cells to each other and maintain the integrity of the epithelial sheet.