Modification of the basic design and function of the kidney of the freshwater fish leading to the development of which of the following allows mammals and birds to produce a hyperosmotic urine?
A)loop of Henle
B)Bowman's capsule
C)collecting ducts
D)glomerulus
E)renal medulla and cortex

Question

Quizplus · Accepted Answer

The loop of Henle, which is absent in the kidneys of freshwater fish, plays a critical role in the production of a hyperosmotic urine in mammals and birds. This is achieved through a countercurrent multiplier system that allows the kidney to concentrate urine to a much higher degree than the surrounding blood plasma. Freshwater fish lack a loop of Henle and therefore cannot produce such highly concentrated urine.

Modification of the Basic Design and Function of the Kidney