question_answer 24)

  Match the following columns.

Column I	Column II
a. Proximal convoluted tubule	1.Formaton of concentrated urine
b. Distal convoluted tubule	2.Filtration of blood
c. Henle?s loop	3. Reabsorption of 70-80% of electrolytes
d. Counter current mechanisms	4. ionic balance
e. Renal corpuscle	5. Maintenance of concentration gradient in medulla.

Codes       A  B  C  D  E                               A  B  C  D  E (a) 3   5  4  2  1                         (b) 3  4   1  5  2 (c) 1   3  2  5  4                         (d) 3   1  4  5  2

Answer:

                  (b) Proximal convoluted tubule is involved in reabsorption of 70-80% of electrolytes. Distal convoluted tubule is involved in secretion of hydrogen, potassium ions and in order to maintain pH and sodium-potassium balance in blood (ionic balance). Henle's loop (the descending limb) is permeable to water, but almost impermeable to electrolytes. This concentrates the urine (filtrate) as it moves down. Counter current mechanisms helps to maintaining a concentration gradient in the medullary interstitium of kidney. Renal corpuscle involves filtration of blood via glomerulus and Bowman's capsule.