Tubular fluid
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
[edit]The composition of tubular fluid changes throughout the nephron, from the proximal tubule to the collecting duct and then as it exits the body, from the ureter.
| 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] | ||||||