Question

explain the mechanism of formation of concentrated urine in mammals

Answer 1

Mechanism of Concentration of the Filtrate: Mammals have the ability to produce a concentrated urine. ... The flow of filtrate in the two limbs of Henle's loop is in opposite directions and thus forms a counter current. The flow of blood through the two limbs of vasa recta is also in a counter current pattern.

Answer 2

The mechanism of formation of concentrated urine in mammals

Explanation:-

• Mammals can produce concentrated urine. The loop of Henle and the vasa recta play an important role in the same.
• The transport of sodium chloride in the ascending limb of the loop of Henle results in an osmotic gradient.
• It is inactive in the thin region of the loop while active in the thick region.
• The hypertonic medulla is produced by the renal tubules and the vasa recta in the following way:-
• There is an active absorption of urea from the collecting duct.
• Passive absorption of water without NaCl occurs in the descending limb of the loop of Henle, which helps to concentrate NaCl entering the ascending limb.
• In the vasa recta, water is absorbed into the blood and the absorbed solute is returned to the interstitium. This is called a countercurrent exchange mechanism.
• Human kidneys can produce approximately four times more concentrated urine than the initial filtrate that is initially formed.