The main disadvantage of urea as an excretory product for animals eliminating it would be:
1. its high toxicity
2. Needs lot of water to be eliminated
3. It being an osmolyte
4. Energy expenditure to produce it
Match each item in Column I with one in Column II and choose the correct option from the codes given below:
|Column I||Column II|
|B.||Normal Blood Urea Level||b.||23%|
|C.||GFR||c.||70-100 mg %|
|d.||15-40 mg %|
A B C
1. b d f
2. a d f
3. a c e
4. b d e
Excretion of dilute urine requires
1. relative permeability of the distal tubule to water
2. transport of sodium and chloride ions out of the descending loop of Henle
3. the presence of ADH
4. impermeability of the collecting tubule to water
The condition where urea accumulates in blood is:
Juxtaglomerular 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 arteriole 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.
Describe urine in relationship to glomerular filtration tubular reabsorption and tubular secretion urine :
1. glomerular filtration + tubular reabsorption + tubular secretion
2. glomerular filtration - tubular reabsorption -tubular secretion
3. glomerular filtration + tubular reabsorption -tubular secretion
4. glomerular filtration -tubular reabsorption +tubular secretion
Atrial natriuretic hormone (ANH) will promote a(n) ________ in the excretion of sodium and water; thus ________ blood volume and blood pressure.
1. decrease, decreasing
2. decrease; increasing
3. increase, decreasing
4. increase, increasing
Removal of proximal convoluted tubule from the nephron will result in
(1) more diluted urine
(2) more concentrated urine
(3) no change in quality and quantity of urine
(4) no urine formation