Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 27

Which of the tubules is impermeable to water?

A. Proximal convoluted tubule

B. Descending loop of Henle

C. Ascending loop of Henle

D. Distal convoluted tubule

Step 1 of 2

Tubules of the nephron:

The structure of Nephron consists of following tubules:

• Proximal convoluted tubule

• Distal convoluted tubule

• Loop of henle

• The collecting ducts.

Impermeability:

• Inability of a porous material to allow the flow of liquid or gas.

• Loop of henle has ascending loop and descending loop where the concentration of urine begins.

Descending loop of henle:

• Here, the water is cleared from the filtrate of urine, and it is impermeable to sodium.

Ascending loop of Henle:

• Here, sodium and chloride are re-absorbed from the filtrate of urine

• Ascending loop of henle is impermeable to water, which prevents excessive reabsorption of water from the urine.

Therefore, “ascending loop of henle” is impermeable to water. Hence, the correct answer is option.