Question

Why are squamous epithelium sometimes called stratified squamous epithelium

Answer 1

Epithelial tissues are identified by both the number of layers and the shape of the cells in the upper layers. There are eight basic types of epithelium: six of them are identified based on both the number of cells and their shape; two of them are named by the type of cell (squamous) found in them. Epithelial tissue is classified based on the number of cells, the shape of those cells, and the types of those cells.

Epithelial Tissue CellsCellsLocationsFunctionSimple squamous epithelium

Air sacs of the lungs and  the lining of the heart, blood vessels and lymphatic vesselsAllows materials to pass through by diffusion and filtration, and secretes lubricating substancesSimple cuboidal epithelium

In ducts and secretory portions of small glands and in kidney tubulesSecretes and absorbsSimple columnar epithelium

Ciliated tissues including the bronchi, uterine tubes, and uterus; smooth (nonciliated tissues) are in the digestive tract bladderAbsorbs; it also secretes mucous and enzymes.Pseudostratified columnar epithelium

Ciliated tissue lines the trachea and much of the upper respiratory tractSecrete mucous; ciliated tissue moves mucousStratified squamous epithelium

Lines the esophagus, mouth, and vaginaProtects against abrasionStratified cuboidal epithelium

Sweat glands, salivary glands, and mammary glandsProtective tissueStratified columnar epithelium

The male urethra and the ducts of some glands.Secretes and protectsTransitional epithelium

Lines the bladder, urethra and uretersAllows the urinary organs to expand and stretch