Question

Classify simple epithelial cells on the basis of shape and position in the body.

Answer 1

1) Simple squamous-

• They are polygonal in shape.
• They are found lining areas where passive diffusion of gases occurs.
• Eg- skin, walls of capillaries, linings of the alveoli of the lungs etc.
  

(2) Simple cuboidal-

They are cuboidal in shape.

• They are secretory, absorptive or excretory in functions.
• Eg- small collecting ducts of kidney, pancreas, and salivary gland.

(3) Simple columnar-

They are long and elongated.

• They can cell can be secretory, absorptive, or excretory.
• They can be 1) Ciliated or 2) Non-ciliated.
• Ciliated columnar is found in fallopian tube and uterus.
• Non-ciliated epithelium also possesses microvilli.
  

(4) Pseudostratified columnar epithelium-

• They can be ciliated or non-ciliated.
• The ciliated type is also called respiratory epithelium as it is almost exclusively confined to the larger respiratory airways of the nasal cavity, trachea, and bronchi.