Vessel
Vasa recta
Medullary microvessels for exchange and oxygen delivery
High-yield
The vasa recta preserve the concentrating environment through countercurrent exchange. This vascular role complements, rather than duplicates, tubular countercurrent multiplication.
Overview
Descending and ascending vasa recta form a medullary vascular network supplied mainly from juxtamedullary efferent arterioles. Opposing flows permit water and solute exchange while limiting loss of the medullary gradient. These vessels also nourish surrounding tubules and remove reabsorbed water.
Reference facts
- Origin
- Arise predominantly from efferent vessels of corpuscles near the corticomedullary junction.
- Course
- Descending bundles enter the medulla, communicate with capillary networks at different depths and return through ascending vessels.
- Branches
- Supply interconnected microvascular plexuses around loops and collecting ducts rather than only isolated one-to-one hairpins.
- Supplies
- Deliver oxygen and nutrients to medullary tissues, including papillary regions, while exchanging water and solutes.
- Drains to
- Ascending medullary vessels return toward cortical and arcuate venous pathways and then the renal vein.
Clinical correlation
Low medullary blood flow, oxygen shunting and transport demand create susceptibility to hypoxia. The concentrated, relatively acidic medullary environment also favors sickling, helping explain hematuria and papillary injury in sickling disorders.
Frequently asked questions
Where does the vasa recta originate?
Arise predominantly from efferent vessels of corpuscles near the corticomedullary junction.
What does the vasa recta supply?
The vasa recta supplies the deliver oxygen and nutrients to medullary tissues, including papillary regions, while exchanging water and solutes.
Where does the vasa recta drain to?
The vasa recta drains to the ascending medullary vessels return toward cortical and arcuate venous pathways and then the renal vein.
What are the branches of the vasa recta?
Supply interconnected microvascular plexuses around loops and collecting ducts rather than only isolated one-to-one hairpins.