Question

The epithelium having cube-shaped cells are present in?
(a) Lining of the kidney tubules
(b) Inner lining of the intestine
(c) Respiratory tract
(d) Ducts of salivary glands
(1) (a), (b) and (c)
(2) (b) and (c) only
(3) (a) and (d) only
(4) (a) and (c) only

Answer 1

Hint: Cube-shaped cells make up the cuboidal epithelium. The epithelium is known as the tissue which is responsible for covering or lining the body, both inside and outside. Cuboidal epithelium is involved primarily in the absorption and secretion of substances.

Complete Step by Step Answer:
The cuboidal epithelium is marked by the presence of cube- shaped cells in a single layer. Because it is involved in absorption it is found in the tubular parts of the kidney where maximum absorption of substances takes place from the glomerular filtrate. These substances include sodium ions, glucose, amino acids, etc. It is also found in the lining of the ducts of glands as it is also involved in the secretion of substances. Thus, it will be present in ducts of salivary glands where it will help in the process of saliva formation.

So, the correct option is option (3), ‘(a) and (d) only’

Additional information:
Now, we will look at the different types of epithelium present in our body.
Squamous epithelium: It is made up of a single layer of flattened cells that will help in the process of diffusion. Eg: Lining of alveoli
Columnar epithelium: It is made up of a single layer of tall, slender cells and is responsible for the absorption of food in the intestine.
Ciliated epithelium: If cuboidal or columnar cells have cilia on their free end, then such epithelium is known as the ciliated epithelium. Eg: Lining of fallopian tubes.

Note:
- Epithelium is divided into simple and compound epithelium based on the number of layers of cells arranged in them.
- A feature of columnar cells is that they have basically located nuclei.
- The cuboidal epithelium of the proximal convoluted tubule of nephron has microvilli present in it.