Collecting duct (magnified)
Tubulus renalis colligens
UrinaryOrgansWhole body
- What it is
- Duct that collects urine from several nephrons and runs straight down through the medulla, merging with others to open at the tip of a renal papilla (papillary ducts of Bellini).
- Function
- Makes the final adjustment of urine: antidiuretic hormone inserts aquaporin-2 water channels, and aldosterone controls sodium and potassium exchange.
- Size
- About 20 mm long, widening toward the papilla.
- Clinical note
- Without ADH or a response to it (diabetes insipidus), many litres of dilute urine are passed each day.