What are the various forms of cells of epithelial tissue? Describe briefly.

Following are the different types of epithelial tissue:
(i) Squamous epithelium. The cells of this tissue are broad, flat forming a pavement like appearance. They are of two types Simple squamous( having a single layer) and stratified squamous ( having many layers). It is found in the alveoli of the lungs. Bowmans capsule, membranous labyrinth of internal ear, peritoneum of coelom and blood vessels, skin etc. 
(ii) Cuboidal epithelium. The cells of this tissue are cube like in appearance. They usually serve as gland cells. Cuboidal epithelium is called glandular epithelium when a portion of the cuboidal tissue moves inward and forms a multicellular gland.  It is found in lining of kidney tubules and salivary glands etc.
(iii) Columnar epithelium. The cells of this tissue are more tall than wide, placed side by side. Their nuclei are situated near the bases. They may have on their free surfaces finger like projections—the microvilli. This tissue usually lines the internal surfaces of stomach and intestine.
Ciliated columnar epithelium. The cells of this tissue are modifications of columnar epithelial cells. They have on their free ends many small, vibratile cilia. These are found in kidney tubules, trachea oviduct etc.


A. Squamous. B. Cuboidal. C. Columnar.

 Striated squamous epithelium.