Vessel
Afferent arteriole
The regulated vascular inlet to a renal corpuscle
High-yield
Afferent dilation tends to raise glomerular pressure when other conditions are unchanged. Prostaglandin-dependent support of perfusion becomes especially important during reduced effective circulating volume.
Overview
An afferent arteriole brings cortical arterial blood to the glomerular tuft. Its smooth muscle adjusts inflow resistance, and granular cells near its terminal part release renin. Efferent resistance and filtration-barrier properties also contribute to glomerular filtration.
Reference facts
- Origin
- Usually arises from a cortical radiate, or interlobular, artery.
- Course
- Approaches the corpuscle's vascular pole and divides into the glomerular capillary network.
- Branches
- Forms glomerular capillary loops; renin-containing granular cells concentrate near its glomerular end.
- Supplies
- Delivers blood to the filtration bed, where water and small solutes enter capsular space across a selective barrier.
- Drains to
- Glomerular blood leaves through an efferent arteriole before entering downstream capillary beds.
Clinical correlation
NSAID inhibition of prostaglandin synthesis can worsen perfusion in susceptible, volume-depleted patients. Strong sympathetic activation constricts renal vessels, while chronic hypertension or diabetes can injure arteriolar walls.
Frequently asked questions
Where does the afferent arteriole originate?
Usually arises from a cortical radiate, or interlobular, artery.
What does the afferent arteriole supply?
The afferent arteriole supplies the delivers blood to the filtration bed, where water and small solutes enter capsular space across a selective barrier.
Where does the afferent arteriole drain to?
The afferent arteriole drains to the glomerular blood leaves through an efferent arteriole before entering downstream capillary beds.
What are the branches of the afferent arteriole?
Forms glomerular capillary loops; renin-containing granular cells concentrate near its glomerular end.