Epithelia are layers of cells resting on a thin, simple membrane known as the basement membrane, or the basal lamina. Within these layers, the cells are connected and in close contact with each other by attachments of the cytoskeleton known as cell-cell adhesions, or junctions. Multiple layers of these cells make up epithelial tissues in vertebrates, which are usually found lining surfaces, such as on the exterior of the skin or in the intestinal walls .
- ↑ Alberts et al. (2008) Molecular Biology of the Cell, 5th Edition, New York: Garland Science, p1131