epithelium
Sign in to saveEpithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial (mesothelial) tissues line the outer surfaces of many internal organs, the corresponding inner surfaces of body cavities, and the inner surfaces of blood vessels. Epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues lack blood or lymph supply, but are supplied by nerves.
AI overview
Epithelium is a thin, protective layer of cells that covers and lines your body—from your outer skin to the inside of your organs and blood vessels. It matters because it serves as a barrier and lining throughout your body, making it one of the four fundamental types of animal tissue.
AI-generated from the Wikipedia summary — may contain errors.
Key facts
- Microanatomy.Name
- Epithelium
- Microanatomy.Image
- Illu epithelium.jpg
- Microanatomy.Caption
- Types of epithelium
via Wikipedia infobox
Article
20 sectionsContents
- Classification
- Simple epithelium
- Stratified epithelium
- Structure
- Location
- Basement membrane
- Cell junctions
- Development
- Cell turnover
- Functions
- Glandular tissue
- Sensing the extracellular environment
- Host immune response
- Clinical significance
- Etymology and pronunciation
- Additional images
- See also
- References
- Further reading
- External links
Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial (mesothelial) tissues line the outer surfaces of many internal organs, the corresponding inner surfaces of body cavities, and the inner surfaces of blood vessels. Epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues lack blood or lymph supply, but are supplied by nerves.
There are three principal shapes of epithelial cell: squamous (scaly), columnar, and cuboidal. These can be arranged in a singular layer of cells as simple epithelium, either simple squamous, simple columnar, or simple cuboidal, or in layers of two or more cells deep as stratified (layered), or compound, either squamous, columnar or cuboidal. In some tissues, a layer of columnar cells may appear to be stratified due to the placement of the nuclei. This sort of tissue is called pseudostratified. All glands are made up of epithelial cells. Functions of epithelial cells include diffusion, filtration, secretion, selective absorption, germination, and transcellular transport. Compound epithelium has protective functions.