The renal circulation supplies the blood to the kidneys via the renal arteries, left and right, which branch directly from the abdominal aorta. Despite their relatively small size, the kidneys receive approximately 20% of the

cardiac output In cardiac physiology, cardiac output (CO), also known as heart output and often denoted by the symbols Q, \dot Q, or \dot Q_ , edited by Catherine E. Williamson, Phillip Bennett is the volumetric flow rate of the heart's pumping output: tha ...

. Each renal artery branches into segmental arteries, dividing further into interlobar arteries, which penetrate the renal capsule and extend through the renal columns between the renal pyramids. The interlobar arteries then supply blood to the arcuate arteries that run through the boundary of the cortex and the medulla. Each arcuate artery supplies several interlobular arteries that feed into the afferent arterioles that supply the glomeruli. After filtration occurs, the blood moves through a small network of venules that converge into interlobular veins. As with the arteriole distribution, the veins follow the same pattern: the interlobular provide blood to the arcuate veins then back to the interlobar veins, which come to form the renal vein exiting the kidney for transfusion for blood.

Structure

Arterial system

The table below shows the path that blood takes when it travels through the glomerulus, traveling "down" the arteries and "up" the veins. However, this model is greatly simplified for clarity and symmetry. Some of the other paths and complications are described at the bottom of the table. The interlobar artery and vein (not to be confused with interlobular) are between two renal lobes, also known as the renal column (cortex region between two pyramids). * Note 1: The renal artery also provides a branch to the inferior suprarenal artery to supply the

adrenal gland The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer adrenal corte ...

. * Note 2: Also called the cortical radiate arteries. The interlobular artery also supplies to the stellate veins. * Note 3: The efferent arterioles do not directly drain into the interlobular vein, but rather they go to the

peritubular capillaries In the renal system, peritubular capillaries are tiny blood vessels, supplied by the efferent arteriole, that travel alongside nephrons allowing reabsorption and secretion between blood and the inner lumen of the nephron. Peritubular capillaries ...

first. The efferent arterioles of the juxtamedullary nephron drain into the vasa recta.

Segmental arteries

The segmental arteries are branches of the renal arteries; there are five named segmental arteries: * superior * inferior * anterior ** anterior superior ** anterior inferior * posterior

Venous system

The venous drainage of the kidney large mirrors its arterial supply, except that there are no segmental veins. The stellate veins arise from the capillaries, then drain successively through interlobular veins and interlobar veins until these converge from across the kidney to form the renal vein for that kidney.

References

External links