what is epithelium? enumerate the characteristic features of different epithila
Answers
Polarity- Epithelium is arranged so there is one free surface (apical surface) and one attached surface (basal surface)
Cellular nature– Cells in epithelium fit closely together side by side and sometimes atop each other to form sheets of cells. These sheets are held together by specialized junctions.
Supported by connective tissue– Attachment to a layer of connective tissue at the basal surface forms a layer called the basement membrane, an adhesive layer formed by secretions from the epithelial cells and the connective tissue cells.
Avascular– Epithelium typically lacks its own blood supply.
Regeneration– Epithelium cells can regenerate if proper nourished.
Absence of nerves (except for a few axons in the deeper layers)
hope it's help
plz mark this in brain liest
Epithelium (/ˌɛpɪˈθiːliəm/) is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs.
Characteristic features
1) Term epithelium was given by Dutch Anatomist Ruysch.
2) Covering of body parts and internal hollow surface of organs.
3) Very little intercellular spaces so cells are compactly arranged.
4 ) Devoid of blood supply and receive nutrients from connective tissues by diffusion. Stria vascularis of Cochlea of internal ear has blood capillaries.
Rests on a non-cellular basement membrane.
5) Cells have good power of regeneration after injury.
6) A tissue with variable origin-skin epidermis (ectoderm), coelomic epithelium (mesoderm) and gut epithelium (endoderm).
7) It may be simple or complex depending upon the thickness of cell layer and morphology.
