Epithelia Types

Simple squamous epithelium are thin and flat and typically used for filtration. They are I found in the kidney's filters and in the air sacs of the lungs.

Endothelium: lining of lymphatic vessels, blood vessels an heart; capillaries are only endothelium

Simple cuboidal epithelium are a single layer of cube-shaped cells. They also filter and are found in small ducts in glands and in kidney tubules.

Simple columnar epithelium are a single layer of tall cells found in the digestive tract and used mainly for absorption and secretion.

Psuedostratified columnar epithelium are a single layer of cells with varying heights, so only some cells reach the surface. They secrete and absorb as well. They are located along the respiratory tract with cilia on top.

Stratified squamous epithelium are squamous in the first layer then cuboidal or columnar in the next layers. The surface cells are constantly rubbed away and replaced. It is located at the external part of the skin and is keratinized.

Stratified cuboidal epithelium are rare and found in the ducts of larger glands, where they excrete. Stratified columnar epithelium are also rare and is located in the pharynx, make urethra, glandular ducts, and at junctions between other epithelia types.

Transitional epithelium is found in the lining of hollow urinary organs. When they stretch, the 6 layers of cuboidal and columnar cells flatten and become 3 layers.