This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: AIIMS 2018, Subject name: Physiology
Which of the following is the diluting segment of kidney? 
Select and explain. 
A. PCT, B. Collecting duct, C. Ascending thick loop Henle, D. Descending loop of Henle
C: Ascending thick loop Henle
Answer: C: Ascending thick loop Henle 
Explanation: Structure Function Glomerulus PCA Descending limb of loop of henle Ascending limb of loop of henle DCT Collecting duct Isotonic ultrafiltration Reabsorption of Na+ H2O, amino acids, HCO3,K+, Ca2+, Cl- Reabsorbs H2O into interstitium, impermeable to solute. Impermeable to H2O,loop diuretics acts here. Resorption of Na, K, Cl, k/a the diluting segment. Thiazide diuretics act here, removes 10% of Na+& Cl-, some H2O also removed. Aka concentrating segment, absorbs 10 - 12% of H2O under ADH, principle cells reabsorbs Na+& secretes K+ , intercalated cells reabsorbs K+ & secretes HCO-3.