Nephron and urine formation
The nephron filters plasma and selectively returns water and solutes or secretes substances to form urine, with regulation along successive segments.
Open interactive lesson & self-check ↗Nephron: filtration and tubular flow
Original conceptual SVG · scalableConceptual path only. Fluid flows Bowman space → proximal tubule → descending / ascending loop → distal tubule → collecting duct.
Start at glomerular filtration
Blood enters the glomerular capillary tuft. Water and small dissolved substances cross a size- and charge-selective filtration barrier into Bowman space; cells and most large plasma proteins are retained.
Track the tubule
The proximal tubule reabsorbs a substantial fraction of filtered sodium, water and nutrients. The loop of Henle contributes to the medullary osmotic gradient.
Finish at the distal nephron
The distal tubule and collecting duct regulate electrolyte and water handling under hormonal and local control. Final urine flows to the renal pelvis.
Reference and next reading
Explore the original curriculum and publisher-hosted resources for full-depth reading; this note is an original schematic introduction, not an exhaustive chapter.