Overflateepitel

Overflateepitel, also known as epithelial tissue, is a fundamental tissue type in the body. It forms continuous sheets that cover the surfaces of the body and line internal organs and cavities. This tissue plays a crucial role in protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception.

The cells that make up overflateepitel are tightly packed together, forming a barrier. These cells are typically polarized, meaning they have distinct apical (surface) and basal (attached) sides. The apical surface faces the external environment or the lumen of an organ, while the basal surface is attached to an underlying basement membrane.

Overflateepitel is classified based on the number of cell layers and the shape of the cells. Simple epithelia consist of a single layer of cells, while stratified epithelia have multiple layers. Cell shapes include squamous (flat), cuboidal (cube-shaped), and columnar (taller than wide). Combinations of these classifications, such as simple squamous or stratified cuboidal, describe specific epithelial types.

Specific functions are often dictated by the type of overflateepitel. For example, simple squamous epithelium in the lungs and blood vessels facilitates diffusion, while the stratified squamous epithelium of the skin provides protection against abrasion and pathogens. Glandular epithelia, specialized for secretion, are found in glands throughout the body. Overflateepitel is also capable of regeneration, allowing it to repair damage and replace worn-out cells.