Vessel
Efferent arteriole
The glomerular outlet that feeds another capillary bed
High-yield
Moderate efferent constriction can support glomerular pressure during reduced perfusion. Severe constriction can reduce flow enough to lower filtration, so the response is not unlimited.
Overview
Blood filtered at a renal corpuscle leaves through an efferent arteriole. The vessel then supplies cortical peritubular capillaries or contributes to the medullary vasa recta. Its resistance affects both pressure within the glomerulus and perfusion of the downstream tubules.
Reference facts
- Origin
- Formed where the glomerular capillary loops reunite at the vascular pole.
- Course
- Exits the corpuscle and distributes blood into a second capillary network around renal tubules or toward the medulla.
- Branches
- Feeds cortical peritubular vessels; efferent vessels of juxtamedullary nephrons contribute to descending vasa recta.
- Supplies
- Supports tubular oxygen delivery and exchange of water and solutes reabsorbed or secreted after filtration.
- Drains to
- Its downstream capillaries return blood through renal venules and cortical radiate, arcuate and interlobar venous pathways.
Clinical correlation
ACE inhibitors and angiotensin-receptor blockers reduce angiotensin-dependent efferent tone. A fall in filtration can be pronounced when both kidneys have severe renal arterial narrowing, or when the only functioning kidney is affected; the effect depends on perfusion and clinical context.
Frequently asked questions
Where does the efferent arteriole originate?
The efferent arteriole arises from the formed where the glomerular capillary loops reunite at the vascular pole.
What does the efferent arteriole supply?
The efferent arteriole supplies the supports tubular oxygen delivery and exchange of water and solutes reabsorbed or secreted after filtration.
Where does blood from the efferent arteriole go?
Its downstream capillaries return blood through renal venules and cortical radiate, arcuate and interlobar venous pathways.
What are the branches of the efferent arteriole?
Feeds cortical peritubular vessels; efferent vessels of juxtamedullary nephrons contribute to descending vasa recta.