Which of the following factors is responsible for the formation of concentrated urine?

Options

A. Hydrostatic pressure during glomerular filtration
B. Low levels of antidiuretic hormone
C. Maintaining hyperosmolarity towards it medullary interstitium in the kidneys
D. Secretion of erythropoietin Juxtaglomerular complex

Answer

B

Explanation

The proximity between loop of henle and vasa recta as well as counter current in them help in maintaining an increasing osmolalrity towards the inner medullary interstitium. This mechanism helps to maintain a concentration gradient in medullary interstitium so human urine is nearly four times concentrated than initial filtrate formed.