Dilution (hypoosmotic urine production):
- reabsorption of solute from tubular fluid without water
- ascending limb of Henle’sloop, distal tubule and collecting duct
Concentration (hyperosmotic urine production): - reabsorption of water from tubular fluid without solute
- late distal tubule and collecting duct
- main effectors:
~ antidiuretic hormone (ADH) or vasopressin
~ medullary interstitial osmotic gradient
.countercurrent multiplication by the loop of Henle
.different solute and water permeabilities and
transports of the nephron segments