The renal circulation supplies the blood to the kidneys via the

renal arteries The renal arteries are paired arteries that supply the kidneys with blood. Each is directed across the crus of the diaphragm, so as to form nearly a right angle. The renal arteries carry a large portion of total blood flow to the kidneys. Up to a ...

, left and right, which branch directly from the

abdominal aorta In human anatomy, the abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of the descending aorta (of the thorax). Structure The abdominal aorta begins at the level of the thoracic d ...

. 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: t ...

. Each renal artery branches into segmental arteries, dividing further into

interlobar arteries The interlobar arteries are vessels of the renal circulation which supply the renal lobes. The interlobar arteries branch from the lobar arteries which branch from the segmental arteries, from the renal artery. They give rise to arcuate 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 Cortical radial arteries, formerly known as interlobular arteries, are renal blood vessels given off at right angles from the side of the arcuate arteries looking toward the cortical substance. The interlobular arteries pass directly outward betwe ...

arteries that feed into the

afferent arteriole The afferent arterioles are a group of blood vessels that supply the nephrons in many excretory systems. They play an important role in the regulation of blood pressure as a part of the tubuloglomerular feedback mechanism. The afferent arteriole ...

s that supply the

glomeruli ''Glomerulus'' () is a common term used in anatomy to describe globular structures of entwined vessels, fibers, or neurons. ''Glomerulus'' is the diminutive of the Latin ''glomus'', meaning "ball of yarn". ''Glomerulus'' may refer to: * the filter ...

. After filtration occurs, the blood moves through a small network of venules that converge into

interlobular veins The stellate veins join to form the interlobular veins, which pass inward between the rays Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science ...

. As with the arteriole distribution, the veins follow the same pattern: the interlobular provide blood to the

arcuate veins The arcuate vein is a vessel of the renal circulation. It is located at the border of the renal cortex and renal medulla The renal medulla is the innermost part of the kidney. The renal medulla is split up into a number of sections, known as the ...

then back to the

interlobar veins The interlobar veins are veins of the renal circulation 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 kidne ...

, which come to form the renal vein exiting the kidney for transfusion for blood.

Structure

Arteries

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 The renal arteries are paired arteries that supply the kidneys with blood. Each is directed across the crus of the diaphragm, so as to form nearly a right angle. The renal arteries carry a large portion of total blood flow to the kidneys. Up to a ...

also provides a branch to the

inferior suprarenal artery The inferior suprarenal artery is a paired artery that supplies the adrenal gland. It usually originates at the trunk of the renal artery before its terminal division, but with many common variations. It supplies the adrenal gland parenchyma, th ...

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 cortex which ...

. * Note 2: Also called the cortical radiate arteries. The interlobular artery also supplies to the

stellate veins The stellate veins are veins that lie beneath the fibrous tunic of the kidney. They are stellate in arrangement and are derived from the capillary network, into which the terminal branches of the interlobular arteries break up. These join to form t ...

. * 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 su ...

first. The efferent arterioles of the

juxtamedullary nephron The nephron is the minute or microscopic structural and functional unit of the kidney. It is composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus and a cup-shaped structure ca ...

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

Veins

The

arise from the capillaries, then drain successively through

and

until these converge from across the kidney to form the renal vein for that kidney.

References

External links