As the filtrate passes upward in the ascending limb of loop of Henle:

1.	it gets diluted due to the reabsorption of water from medullary interstitium
2.	it gets diluted due to the passage of electrolytes to medullary interstitium
3.	it gets concentrated due to the reabsorption of electrolytes from medullary interstitium
4.	it gets concentrated due to the passage of water to medullary interstitium

In majority of the nephrons, the loop of Henle:
1. is absent
2. extends only a little into the medulla
3. extends deep into the medulla
4. is associated with a highly developed vasa recta

Aderenal cortex releases aldosterone when activated by:
1. ADH
2. Low potassium concentration in ECF
3. Angiotensin II
4. Renin

Juxtamedullary nephrons:
1. are more common than cortical nephrons
2. do not have a well developed vasa recta associated with them
3. play a very important role in concentration of urine
4. produce angiotensinogen

The location of kidneys in humans can be best described as:

Urination will be caused by simultaneous:

Aldosterone can be secreted by adrenal cortex when it is stimulated most directly by:

During concentration of urine, NaCl is returned to medullary interstitium by:
1. Ascending limb of Loop of Henle
2. Descending limb of Loop of Henle
3. Ascending limb of Vasa Recta
4. Descending limb of Vasa Recta

During the counter current mechanism, small amount of urea from interstitium enters:
1. the collecting duct
2. the thin segment of ascending limb of loop of Henle
3. the ascending limb of vasa recta
4. the descending limb of vasa recta

What is the number of times that the human kidneys can maximally concentrate the initial filtrate?