NEET PG DENTAL EXAM

Detailed explanation-1: -The filtrate flows from the proximal tubule and into the Loop of Henle. The loop of Henle concentrates the filtrate, by removing more water from it, and passes it to the distal tubule. From the distal tubule it travels to the collecting duct-now called urine.

Detailed explanation-2: -At the end of the distal convoluted tubule, the filtrate empties into collecting ducts, where it combines with filtrate from other nephrons. Collecting ducts move back into the medulla, which is salty, so more water leaves through passive diffusion.

Detailed explanation-3: -The distal convoluted tubule helps to control sodium and water levels, and the collecting duct has a role in acid/base balance as well as water reabsorption. At the very end of the collecting duct, the filtrate becomes urine.

Detailed explanation-4: -Tubular secretion occurs mostly in the PCT and DCT where unfiltered substances are moved from the peritubular capillary into the lumen of the tubule. Secretion usually removes substances from the blood that are too large to be filtered (ex: antibiotics, toxins) or those that are in excess in the blood (ex: H+, K+).