Question

Differentiate between simple epithelium and compound epithelium.

Answer 1

Hint: Simple and compound epithelium classification is based on the number of cell layers. Both have different functions and present in different regions of our body based on the requirements.

Complete answer:
The simple epithelium consists of only a single layer of cells that lie on a basement membrane. It is single-layered and therefore is found in areas where absorption of substances occurs. The compound epithelium has more than one layer of epithelial cells, and they are present on surfaces where the chances of wear and tear are high.
The differences between simple and compound epithelium are given below:

Simple Epithelium	Compound Epithelium
A single layer of cells	Multiple layers of cell
Helps in the absorption and excretion of a substance by diffusion	Help in protecting regions of wear and tear
It is of four types, squamous, columnar, ciliated, and pseudostratified.	It is mainly of two types, stratified, and transitional. But subdivisions are also present under stratified.
Present in the lining of lung alveoli, endothelium.	Present on the skin, esophagus, tongue.

Additional Information:
 Epithelial tissues have some unique properties, which are:
-Closely packed cells are present
-The cells are present over a basement membrane.
-No capillaries are present in epithelial tissues.
-The epithelial cells undergo continuous destruction and reformation, this is known as turn over.
The main functions of epithelial tissue are:
-Protection: Protection from external stresses.
-Absorption: Absorption of simple food substances like amino acids, glucose, etc.
-Secretion: Secretion of mucous in different organs of the body.
-Lubrication: Lubrication in coverings of organs, like pericardium on the heart.

Note: Epithelial tissue be it simple epithelial tissue or compound epithelial tissue, does not have any vascular supply, but they obtain nutrition. This happens by the process of simple diffusion from the cells of the surface they are covering, through the basement membrane.