Epithelial Tissue

The epithelium is a sheet of aggregated cells of similar type that covers body surfaces, lines hollow organs or modified to form glands or neuroepithelium.

General Features of Epithelium

  • It may originate from all three embryonic germ layers (ectoderm, mesoderm and endoderm).
  • It is composed of high number of closely applied cells with very little intercellular substances.
  • It is separated from the underlying connective tissue by a basement membrane.
  • It is avascular, blood and lymph vessels do not penetrate the basement membrane. Thus, it receives its nutritional support by diffusion.
  • The epithelial cells have high capacity for regeneration.
  • The epithelium can change from one form to another in a process called metaplasia.

  • It performs many functions such as protection, secretion, excretion, absorption and sensory reception.

Epithelium

The epithelium is a sheet of cells that covers body surface, lines hollow organs or modified to form glands and neuroepithelium.


What is the most difficult part in this section? send email to:drhany@mansvet.com

Objectives:

After the completion of this chapters you will be able to:

  • enumerate the general epithelial features
  • classify epithelium
  • enumerate types and give examples
  • illustrate the different types of simple epithelium.
  • illustrate the different types of stratified epithelium.
  • classify glands
  • describe the structure of myo- and neuroepithelium.

Quiz

  1. Enumerate the features of epithelium?
  2. Classy epithelium and describe the histological structure of each type?
  3. Enumerate basal, lateral and apical modifications?
  4. Classify glands and describe the structure of each type?