Counter Current Mechanism

Assertion :- Human kidneys can produce urine nearly four times concentrated than the initial filtrate formed. Reason :- Counter current mechanism helps to maintain a concentration gradient in the medullary interstitium.

The increase in osmolarity from outer to inner medullary interstitium is maintained due to : (i) Close proximity between Henle's loop and vasa recta (ii) Counter current mechanism (iii) Selective secretion of HCO 3¯ and hydrogen ions in PCT (iv) Higher blood pressure in glomerular capillaries

Match column I with column II and select the correct option from the codes given below. {:("Column I","Column II"),(A." PCT",(i)." Minimum reabsorption"),(B." DCT",(ii)." Filtration of blood"),(C." Loop of Henle",(iii)." Reabsorption of 70-80% electrolytes"),(D." Counter current mechanism",(iv)." Ionic balance"),(E." Renal corpuscle",(v)." Maintenance of concentration gradient in medulla"):}

Assertion : Normal urine of man is hypertonic than the blood plasma. Reason : Counter-current mechanism of loop of Henle and Renin enzyme of juxta-glomerular cells increase the Na^(+) concentration in the adrenal medulla.

Read the statements given below A. The renal cortex extends between the medullary pyramids as Columns of Bertini. B. ATP molecules are used in kidneys to convert NH3 to urea. C. Reabsorption of water in PCT and loop of Henle is obligatory. D. High medullary osmolarity is mainly developed due to NaCI and urea by counter current mechanism of vasa recta and loop of Henle. The correct statements are

Fill in the blanks: 1. In counter current mechanism, NaCl is transported by the ...a... limb of Henle’s loop which is exchanged with the .....b. limb of vasa recta. 2. NaCI is returned to the interstitium by ascending portion of .....c.. 3. Small amount of Urea enter the ......d segment of ...a... limb of Henle’s loop which is transported back to the interstitium by the ...e... .

Counter current machanism helps in concentrating urine in animals and mainly operaters on {:(a.,"Henle's loop",b.,"Vasa-react"),(c.,"PCT",d.,"DCT"):}

 Which factor helps in maintaining an increasing osmolality towards the inner medullary interstitium?  a. Counter current pattern in vasa recta b. Counter current pattern in Henle’s loop c.proximity between the Henle’s loop and vase recta

 Which factor helps in maintaining an increasing osmolality towards the inner medullary interstitium?  a. Counter current pattern in vasa recta b. Counter current pattern in Henle’s loop c.proximity between the Henle’s loop and vase recta