How Does the Loop of Henle Enable the Mammalian Kidney

question 37

Multiple Choice

How does the loop of Henle enable the mammalian kidney to produce hyperosmotic urine?
I-The ascending limb of the loop actively extrudes Na+.
II-The descending limb interacts with the ascending limb to raise the concentration of the extracellular fluid in the renal medulla.
III-The concentration is further enhanced by the presence of urea,which draws water out of the collecting ducts by osmosis.

• A)just I
• B)II and III
• C)just III
• D)I and II
• E)I,II,and III