netter113

Urine Dilutior

RENAL PHYSIOLOGY

h₂o

Na Cl"

h₂o

375 —*t- Urea

Notę: Figurcs given are exemplary rather than spetific

Figurę 6.11 Dilution of ihe Urine

The excretion ot dilute unne requires norm.il funcliori of ihe loop of Henie tespecially the thick ascending limb) and the distal tubule, delivery ot adequate amounts of tubule fluid to these segments, and the ahsence ot ADH. Under optimal conditions, this results in the excretion ot 18 L/day of urine having an osmolality of 50 mOsm/kg

HX). Notę that the osmolality of the medullary interstitium is reduced. This results trom increased vasa recta hlood flow (corrw with Figurę 6.10) and urea removal by the collecting duet.

130