Question

Lining of kidney tubules is made up of
A) Columnar epithelium
B) Cuboidal epithelium
C) Squamous epithelium
D) Pseudostratified epithelium

Answer 1

Hint: Epithelium or epithelial tissue is the simplest protective tissue. It forms the lining of hollow organs & cavities within the body.

Complete Answer:
Lining of kidney tubules is made up of cuboidal epithelium. It consists of a single layer of cube-like (cuboidal) cells with large, spherical nuclei located in the centre. In the kidney tubules, the cells help in the absorption and transportation of filtered substances.

A) Cuboidal epithelium is also found in salivary glands, sweat glands and thyroid vesicles. They help in absorption, secretion and excretion. It also helps in protection.

B) The columnar epithelium consists of columnar cells which are pillar- like i.e., taller than broader. The columnar cells are attached to the basement membrane. The nuclei are oval shaped located towards the base. It forms the lining of the stomach and small intestine and large intestine. Its main functions are absorption and secretion.

C) Squamous epithelium is made up of flat & irregular shaped cells. The cells are closely packed. It forms the lining of cavities (mouth, oesophagus, nose, alveoli etc) and blood vessels. This squamous epithelium provides protection against mechanical injuries. It also prevents the entry of germs.

D) A pseudostratified epithelium is a simple epithelium. It is made up of epithelial cells. The cells are too crowded as a result nuclei are disposed of at different levels. It may be classified as ciliated (with cilia) and non-ciliated (without cilia). Ciliated pseudostratified epithelium forms the lining of trachea and parts of the upper respiratory tract. Whereas non-ciliated pseudostratified epithelium forms the lining of vas deferens.

Note: The lining of kidney tubules is made up of cuboidal epithelium which increases the surface area for reabsorption of essential nutrients, water and electrolytes.