What is used as an osmolyte in human beings to increase medullary interstitial osmolality during concentration of urine?
1. TMAO
2. Urea
3. Both a and b 
4. Uric acid

During the concentration of urine by the human kidneys, NaCl is returned to the medullary interstitium by the:

1. Descending limb of the loop of Henle

2. Ascending limb of the loop of Henle

3. Descending limb of the vasa recta

4. Ascending limb of the vasa recta

Kidney matrix retains some amount of urea to

1.Maintain a desired osmolarity

2.Maintain metabolism

3.Maintain balance of the body

4.Maintain micturition

Which of the following is not a part of urine formation?

1.Glomerular Filtration

2.Reabsorption

3.Secretion

4.Counter current mechanism

Which segment allows the passage of small amounts of urea into the medullary interstitium to keep up the osmolarity?

1.PCT

2.DCT

3.LOH

4.Collecting Duct

Which of the following is the correct way of writing the unit of osmolarity?

1. Mosmo/L

2. mOsmol/L

3. MOsmo/L

4. mOSMol/L

The gradient is mainly caused by

1.NaCl

2.Urea

3.Both A and B

4.Ammonia

The NaCl is transported by the ascending limb of Henle's loop which is exchanged with the…….

1. Ascending limb of vasa recta

2. Descending limb of vasa recta

3. Ascending limb of LOH

4. Descending limb of LOH

Urea will enter the

1.Thin segment of AL of LOH

2.Thick segment of AL of LOH

3.Descending Limb of LOH

4.All of these

Urea is transported back to the interstitium by

1.Collecting Tubule

2.DCT

3.PCT

4.LOH