EXCRETORY SYSTEM
KIDNEY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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create a high water potential in the medulla
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create a low water potential in the medulla
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excrete excess ions into the urine
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allow water to be reabsorbed into the proximal convoluted tubule by osmosis
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Detailed explanation-1: -The ascending limb (where loop diuretics work) is impermeable to water. NaCl is pumped from the tubule into the interstitium in the ascending limb. The tubular osmolarity decreases and fluid that leaves the loop is hypotonic.
Detailed explanation-2: -The primary site of sodium reabsorption in the Loop of Henle is the thick ascending limb (TAL). The TAL is impermeable to water. Sodium reabsorption is active – the driver is the Na+/K+ ATPase on the basolateral membrane which actively pumps 3 Na+ ions out of the cell and 2 potassium (K+) ions into the cell.
Detailed explanation-3: -1) Ascending limb of loop of Henle is impermeable to electrolytes, but is permeable to water.
Detailed explanation-4: -Sodium is actively pumped out, while potassium and chloride diffuse down their electrochemical gradients through channels in the tubule wall and into the bloodstream. The walls of the thick ascending limb are impermeable to water, so in this section of the nephron water is not reabsorbed along with sodium.