Question

Uriniferous tubules of a kidney are concerned with the formation of
A. Glucose
B. Amino acids
C. Hormones
D. Urine

Answer 1

Kidneys are two reddish brown bean shaped organs located at the rear wall of the abdominal cavity and protected by a rib cage. They are retroperitoneal. They are concerned with the filtration of blood and also help to regulate and maintain optimum water-electrolyte balance in the blood. Let us know more about it to find the correct answer.

Complete answer:
Let us first know about the kidneys.
So as said above, kidneys are involved in filtration of blood and in maintaining water-electrolyte balance in the blood. Nephrons are the structural and functional units of kidneys. It majorly consists of-
Renal corpuscle: blood filtering component composed of a tuft of capillaries called glomerulus and a capsule called Bowman’s capsule.
Renal tubules or uriniferous tubules- contains tubular fluid filtered by the glomerulus. It can further be divided into-
Proximal convoluted tubules: mainly concerned with the absorption of filtrate in accordance with homeostasis. It is located in the renal cortex.
Loop of Henle: hairpin like structure situated in the renal medulla.
Descending limb: highly permeable to water and less permeable to ions
Ascending limb of loop of Henle: impermeable to water.
Distal convoluted tubule: involved in the homeostasis of potassium, sodium and divalent cations.
Collecting tubules: transportation of filtrate and reabsorption of water.
Medullary ray is a collection of renal tubules ultimately draining into a single collecting duct.
Let us now understand the basic three steps that accompany as the filtrate passes down the nephrons-
Ultrafiltration: blood entering the renal corpuscle gets filtered under high pressure by the renal corpuscle which then passes through the Bowman’s capsule down the renal tubules.
Reabsorption: down the tubules and loop of Henle, the required ions and water molecules are reabsorbed in blood so as to maintain water- electrolyte balance in accordance with homeostasis.
Secretion: substances such as hydrogen ions, creatinine, etc are removed from blood.
Finally the filtrate that remains after it has been processed by all these three processes is called urine.

Based on the above description, it is clear that the correct answer is (D)- Urine.

Note:

The concentration of urine gets affected by the amount of fluid in the body. When there is more than normal amount of fluid in blood, urine gets diluted as there is less reabsorption of water molecules in blood. The opposite happens when there is less than normal amount of fluid in the body.
The vasa recta and renal tubules in the kidney operate under counter-current mechanisms so that an adequate osmolarity is maintained.