Describe the pathway of urine from the nephron to the exterior.

• A. Glomerulus/Bowman’s capsule filtrate enters proximal tubule after filtration.
• B. Glomerulus/Bowman’s capsule filtrate enters proximal tubule -> loop of Henle -> distal convoluted tubule -> collecting duct -> renal pelvis -> ureter -> bladder -> urethra.
• C. Filtrate travels from glomerulus directly to urethra.
• D. Filtrate goes from collecting duct to bladder first.

Answer: (B)

Urine follows a precise journey through the nephron and then the urinary tract. Filtrate is produced when blood is filtered in the glomerulus and collected in Bowman's capsule. From there it moves into the proximal tubule, where a large amount of reabsorption and some secretion occur. It then traverses the loop of Henle, continues to the distal convoluted tubule, and finally reaches the collecting duct, where final adjustments to concentration occur. After leaving the nephron, the urine collects in the renal pelvis, passes down the ureter to the bladder, and is excreted through the urethra. This sequence cannot be skipped or reordered, which is why the described route is correct.