- Compound Epithelium
It consists of more than one layer of cells. Only the cells of the deepest layer rest on the basement membrane. Being multilayered, compound epithelia have little role in secretion or absorption, but they provide protection to underlying tissues, against mechanical, chemical, thermal or osmotic stresses.
Epithelium covers moist surfaces such as those of buccal cavity, pharynx and oesophagus.
- Transitional Epithelium is much thinner and more stretchable than the stratified epithelium. It lines the inner surface of the urinary bladder and ureter. It allows considerable expansion of these organs to accommodate urine.
The cells of glandular epithelia are generally columnar or cuboidal. The glandular epithelium can be classified into two types: unicellular, consisting of isolated glandular cells (e.g. goblet cell of alimentary canal), and multicellular, consisting of cluster of cells.