Question

The absorption of useful material from urine before it passed out takes place through…………epithelium tissue.
A. Cuboidal
B. Ciliated columnar
C. Columnar
D. Stratified squamous

Answer 1

Hint: Human kidney has nearly one million complaint tubular structures called nephrons. Nephrons are the functional units of the kidney. Nephron has two parts: The glomerulus and the renal tubule PCT is lined by simple cuboidal brush border epithelium.

Complete Answer:
A. Cuboidal: Cuboidal is composed of a single layer of cube-like cells. This is commonly found in ducts of glands and tubular parts of nephrons in kidneys.
(i) Its main function is secretion and absorption.
(ii) The epithelium of proximal convoluted tubules (PCT) of nephron in the kidney has microvilli.
(iii) They increase the area for absorption.

B. Ciliated columnar: It consists of columnar cells which bear cilia on the free surface. It lines the nasal passage, oviducts (fallopian tubes), terminal bronchioles, ventricles of the brain and central canal of the spinal cord of the embryo.

C. Columnar: (i) This epithelium consists of cells that are much taller than wide.
(ii) They line the stomach, intestine and gallbladder.

D. (i) Stratified squamous: It consists of several layers of cells.
(ii) It lines the buccal cavity, pharynx, oesophagus, vagina, sweat glands, ducts, salivary and pancreatic duct.

The correct option is A.

Note: (i) Word epithelium was introduced by Ruysch.
(ii) The cuboidal epithelium lines the small salivary and pancreatic ducts. Here it is non-secretory.
(iii) It also lines the sweat, salivary and thyroid glands, where it is secretory.
(iv) In PCT, cuboidal cells have numerous microvilli at their free ends.
(v) Villi increases surface area for proper reabsorption of materials.