Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Epithelial tissue is a sheet of cells that covers body surfaces or cavities, including the lining of organs and the outer surface of the body. It serves as a barrier against harmful microorganisms, and aids in absorption, secretion, and sensation.
Related terms
Squamous epithelium: This is a type of epithelial tissue made up of flat cells that resemble tiles, providing a smooth surface for diffusion and filtration.
Glandular epithelium: Specialized for secretion, this type involves cells that are organized to produce and release substances such as enzymes, hormones, milk, mucus, sweat, or oil.
Basement membrane: A thin layer of fibrous material that anchors the epithelium to underlying connective tissues, providing support and regulating exchange of materials between the epithelium and surrounding structures