
Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Tubular fluid
Introduction
Template:Search infobox Steven C. Campbell, M.D., Ph.D.
Overview
Overview
Tubular fluid is the fluid in the tubules of the kidney. It starts as a renal ultrafiltrate in the glomerulus, changes composition through the nephron, and ends up as urine leaving through the ureters.
Composition table
Composition table
The composition of tubular fluid changes throughout the nephron, from the proximal tubule to the collecting duct:
| Substance | proximal tubule | loop of Henle | Distal convoluted tubule | Collecting duct system | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| S1 | S2 | S3 | descending limb | thin ascending limb | thick ascending limb | connecting tubule | initial collecting tubule | cortical collecting ducts | medullary collecting ducts | ||
| Na+ | 142[1] | 142[1] | 100[1] | 70[1] | 40[1] | ||||||
