Renal Vascular Anatomy
|Renal Arterial Blood Supply|
- About 25% of the cardiac output goes to the kidneys through the renal arteries which branch off of the descending aorta. The renal arteries then progressively branch around the renal pyramids in the following order: Renal Artery -> Renal Interlobar Arteries -> Renal Arcuate Arteries -> Renal Interlobular Arteries -> Branch off into individual nephron blood supplies.
- The kidney is unique in that it has a double set of arterioles and a double set of capillaries for each nephron. The reference point for the nephronic blood supply is the glomerulus, and as seen below, each glomerulus is its own mini-portal vessel system.
- Renal Afferent Arterioles: Lie before the glomerulus and bring blood into the glomerular capillaries
- Glomerular Capillaries: Are a small tuft of capillaries that lie within the glomerulus
- Renal Efferent Arterioles: Lie after the glomerulus and drain blood from the glomerular capillaries
- Peritubular Capillaries: A second bed of capillaries that lie after the renal efferent arterioles and surround the cortical regions of the nephron
- Vasa Recta: These are a specialized set of capillaries which dip far into the renal medulla and surround the loop of Henle. They are the only blood vessels which perfuse the renal medulla, which is thus highly prone to infarction.
- The venous blood supply of the kidney matches that of the arterial blood supply. Blood draining from the peritubular capillaries enters interlobular veins which join arcuate veins that drain into Interlobar Veins which ultimately combine into the renal vein.