OSMOLARITY

How many of the following functions can be correctly correlated with loop of Henle ? A. Reabsorption of nearly all of the essential nutrients. B. Reabsorption in this segment is minimum. C. A significant role in the maintenance of high osmolarity of medullary interstitial fluid. D. Reabsorption of 70-80 percent of electrolytes and water. E. Conditional reabsorption of Na^(+) .

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

I. Reabsorption in this region is minimum. II. This region plays a significant role in the maintenance of high osmolarity of intestinal fluid III. Its descending limb is permeable to water but almost impermeable to electrolytes IV. Its ascending limb is impermeable to water but allows transport of electrolyte actively or passively V. In descending limb filtrate is hypertonic while in ascending limb filtrate is hypotonic The above characteristics are associated with -

Read the following statements about the excretory system in humans: I. A fall in GFR can activate the JG cells to release renin. II. ADH can also affect the kidney function by its constrictory effects on blood vessels. III. The proximity between the Henle's loop and vasa recta, as well as the counter-current in them help in maintaining an increasing osmolarity towards the outer medullary interstitium. IV Our lungs remove large amounts of CO_(2) (108 litres/day). V. Renal calculi are the stone or insoluble mass of crystallised salts like oxalates within the kidney. How many of these are correct?

In the following questions , a statement of assertion (A) is followed by a statement of reason (R). A: ADH response is observed during increased osmolarity due to dehydration. R : Vasopressin promotes water uptake from collecting ducts and DCT.

Assertion :- The descending limb of loop of Henle is permeable to water but almost impermeable to electrolytes. Reason :- Henle's loop plays a significant role in the maintenance of high osmolarity of medullary interstitial fluid.

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

Which of the following statements is/are incorrect regarding the collecting duct? (i). It extends from the cortex to medulla. (ii). Large amount of water could be reabsorbed by it to produce concentrated urine. (iii). Small amount of urea diffuses into it from the medulla to keep up the osmolarity. (iv). it plays a role in maintaining pH and ionic balance of blood by the selective secretion of H^(+) and K^(+) ions.

Select the option which describes the correct parts of the human brain with the functions mentioned below: I. It contains association areas that are responsible for complex functions like intercessory associations, memory and communication. II. It controls osmolarity of body fluids, urges for eating and drinking. III. It is involved in the regulation of sexual behaviour , expression of emotional reactions. IV. It controls cardio - vascular reflexes and gastric secretions.