Vasa recta in cortical nephrons :

1. Arises from afferent arteriole rather that efferent arteriole

2. Does not get involved in counter current exchange with loop of henle

3. Carries deoxygenated blood rich in urea

4. Is absent or highly reduced 

The proximal convoluted tubule is lined by the:
1. Simple cuboidal epithelium
2. Simple columnar epithelium
3. Simple cubodial brush bordered epithelium
4. Simple columnar brush bordered epithelium

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

(a) Descending limb of the loop of Henle

(b) Ascending limb of the loop of Henle

(c) Descending limb of the vasa recta

(d) Ascending limb of the vasa recta

An increase in the blood flow to the atria of the heart can cause the release of:

1. Erythropoeitin

2. Atrial natriuretic factor

3. Renin

4. Aldosterone

On average, what amount of urea is excreted out per day by a healthy human being?

1. 5-10 gm

2. 15-20 gm

3. 25-30 gm

4. 50-60 gm

The normal value of GFR is approximately

1. 650 ml/min

2. 180 ml/min

3. 180 ml/day

4.125 ml/min

Which of the following does not help in excretion in Periplaneta americana

1. Fat body

2. Urecose glands

3. Nephrocytes

4. None of these

Juxta glomerular apparatus is a special sensitive region formed by cellular modifications in the:

(1) DCT and Efferent arteriole at the point of their contact

(2) DCT and the Afferent arteriole at the point of their contact

(3) PCT and Afferent arteriole at the point of their contact

(4) PCT and Efferent ateriole at the point of their contact

Which of the following statements about the kidneys is incorrect?

1. They consume over 20% of the oxygens used by the body at rest.

2. Approximately 1200ml of fluid is filtrated by the kidneys each day.

3. 120-125 ml of plasma is forced into the renal tubules each minutes.

4. They compose less than 1% of the body weight.

Regarding the control of water balance by the kidneys:
1. The renal medulla has an osmotic gradient that decreases from the border with the cortex to the renal papilla.

2. ADH is secreted by anterior pituitary in response to a decrease in the osmolality of the blood.

3. A normal person cannot produce urine with an osmolality greater than 300 mOsmil.kg-1.

4. ADH acts on the cells of the collecting ducts to increase their permeability to water.