The renal veins are large-calibre

vein Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated ...

s that drain blood filtered by the

kidneys The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; bloo ...

into the

inferior vena cava The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of th ...

. There is one renal vein draining each kidney. Because the inferior vena cava is on the right half of the body, the left renal vein is longer than the right one.

Structure

One renal vein drains each

kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...

. A renal vein is situated anterior to its corresponding accompanying

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 ...

. The renal veins empty into the

, entering it at nearly a 90° angle. Due to the right-ward displacement of the inferior vena cava from the midline, the left renal vein is some 3 times longer than the right one (~7.5 cm and ~2.5 cm, respectively). The renal vein divides into 4 divisions upon entering the kidney: * the anterior branch which receives blood from the anterior portion of the kidney and, * the posterior branch which receives blood from the posterior portion.

Tributaries

Because the tributaries of the

are not bilaterally symmetrical, the left renal vein often receives the ipsilateral

inferior phrenic vein The inferior phrenic veins drain the diaphragm and follow the course of the inferior phrenic arteries; * the right ends in the inferior vena cava; * the left is often represented by two branches, ** one of which ends in the left renal or supra ...

suprarenal vein The suprarenal veins are two in number: * the ''right'' ends in the inferior vena cava. * the ''left'' ends in the left renal or left inferior phrenic vein. They receive blood from the adrenal glands The adrenal glands (also known as suprare ...

, gonadal vein (

left testicular vein The testicular vein (or spermatic vein), the male gonadal vein, carries deoxygenated blood from its corresponding testis to the inferior vena cava or one of its tributaries. It is the male equivalent of the ovarian vein, and is the venous counte ...

in males,

left ovarian vein The ovarian vein, the female gonadal vein, carries deoxygenated blood from its corresponding ovary to inferior vena cava or one of its tributaries. It is the female equivalent of the testicular vein, and is the venous counterpart of the ovarian ...

in females), and 2nd

lumbar vein The lumbar veins are four pairs of veins running along the inside of the posterior abdominal wall, and drain venous blood from parts of the abdominal wall. Each lumbar vein accompanies a single lumbar artery. The lower two pairs of lumbar veins a ...

.Dissector Answers - Kidney & Retroperitoneum
This is in contrast to the right side of the body, where these veins drain directly into the IVC.

Relations

The anatomical relations of the two renal veins are bilaterally asymmetrical. Left renal vein The left renal vein is situated posterior to the

splenic vein The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes .

, and the

body of the pancreas The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an endoc ...

. It passes through the angle formed by the abdominal aorta (situated posteriorly), and

superior mesenteric artery In human anatomy, the superior mesenteric artery (SMA) is an artery which arises from the anterior surface of the abdominal aorta, just inferior to the origin of the celiac trunk, and supplies blood to the intestine from the lower part of the du ...

(situated anteriorly) (increased acuteness of this angle may lead to the left renal vein being "pinched" between the two arteries, with the resulting compression impairng blood flow through the vein, a condition known as nutcracker syndrome). Occasionally, the left renal vein (or accessory left renal vein) passes posterior to the aorta. Right renal vein The right renal vein is situated posterior to the descending part of the

duodenum The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear, and the terms anterior intestine or proximal intestine m ...

Variation

There is typically a single renal vein drainin each kidney, but accessory renal veins are commonly encountered; renal vasculature anomalies are more frequent with ectopic kidneys, and almost always present with horseshoe kidney). In some individuals, the left renal vein passes posterior to the abdominal aorta instead of in anterior to it; this is termed a retro-aortic left renal vein (also known as "The Vein of Schnitker"). If there is both a vein passing in front of and one behind the aorta this is called a circumaortic renal vein. In the case of a left sided IVC and the right renal vein passes behind the abdominal aorta, this is termed a retroaortic right renal vein, which is also known as “The Reverse Vein of Schnitker”.

Clinical significance

Diseases associated with the renal vein include

renal vein thrombosis Renal vein thrombosis (RVT) is the formation of a clot in the vein that drains blood from the kidneys, ultimately leading to a reduction in the drainage of one or both kidneys and the possible migration of the clot to other parts of the body. Firs ...

(RVT) and nutcracker syndrome (renal vein entrapment syndrome).

Additional images

File:3D rendered CT of abdominal aortic branches and kidneys.svg, 3D-rendered computed tomography, showing one renal vein (in red color) for each kidney File:Illu kidney2.jpg, Frontal section through the kidney File:Gray480.png, Diagram showing completion of development of the parietal veins. File:Gray577.png, The venæ cavæ and azygos veins, with their tributaries. File:Slide11iii.JPG, Renal vein File:Gray1120.png, Human kidneys viewed from behind with spine removed. File:Njuren.gif, Kidney File:Slide4nn.JPG, Renal vein File:Slide14iii.JPG, Renal vein File:Slide1kkk.JPG, Renal vein

References

External links

* - "Retroperitoneal structures on the posterior abdominal wall." {{Authority control Veins of the torso