Renal artery

Renal artery
Renal arteries branching left and right from the aorta (in red)
1. Renal pyramid 2. Interlobular artery 3. Renal artery 4. Renal vein 5. Renal hilum 6. Renal pelvis 7. Ureter 8. Minor calyx 9. Renal capsule 10. Inferior renal capsule 11. Superior renal capsule 12. Interlobar vein 13. Nephron 14. Renal sinus 15. Major calyx 16. Renal papilla 17. Renal column
Details
Source	Abdominal aorta
Branches	Inferior suprarenal artery, segmental arteries
Vein	Renal vein
Supplies	Kidneys
Identifiers
Latin	Arteria renalis
MeSH	A07.231.114.745
TA	A12.2.12.075
FMA	14751
Anatomical terminology [edit on Wikidata]

The renal arteries normally arise off the side of the abdominal aorta, immediately below the superior mesenteric artery, and supply the kidneys with blood. Each is directed across the crus of the diaphragm, so as to form nearly a right angle with the aorta.

The renal arteries carry a large portion of total blood flow to the kidneys. Up to a third of total cardiac output can pass through the renal arteries to be filtered by the kidneys.

Structure

It has a radius of approximately 0.25 cm,^[1] 0.26 cm at the root.^[2] The measured mean diameter can differ depending on the imaging method used. For example, the diameter was found to be 5.04 ± 0.74 mm using ultrasound, but 5.68 ± 1.19 mm using angiography.^[3][4]

Due to the position of the aorta, the inferior vena cava, and the kidneys in the body, the right renal artery is normally longer than the left renal artery.^[5][6]

• The right passes behind the inferior vena cava, the right renal vein, the head of the pancreas, and the descending part of the duodenum.
• The right is somewhat lower than the left; left artery lies behind the left renal vein, the body of the pancreas and the splenic vein, and is crossed by the inferior mesenteric vein.

Branches

Before reaching the hilus of the kidney, each artery divides into four or five branches; the greater number of these (anterior branches) lie between the renal vein and ureter, the vein being in front, the ureter behind, but one or more branches (posterior branches) are usually situated behind the ureter.

Each vessel gives off some small inferior suprarenal branches to the suprarenal gland, the ureter, and the surrounding cellular tissue and muscles.

One or two accessory renal arteries are frequently found, especially on the left side since they usually arise from the aorta, and may come off above (more common) or below the main artery. Instead of entering the kidney at the hilus, they usually pierce the upper or lower part of the organ.

Variation

The arterial supply of the kidneys is variable and there may be one or more renal arteries supplying each kidney. It is located above the renal vein. Supernumerary renal arteries (two or more arteries to a single kidney) are the most common renovascular anomaly, occurrence ranging from 25% to 40% of kidneys.

Clinical significance

Renal artery stenosis, or narrowing of one or both renal arteries will lead to hypertension as the affected kidneys release renin to increase blood pressure to preserve perfusion to the kidneys. RAS is typically diagnosed with duplex ultrasonography of the renal arteries. It is treated with the use of balloon angioplasty and stents, if necessary.

Atherosclerosis can also affect the renal arteries and can lead to poor perfusion of the kidneys leading to reduced kidney function and, possibly, renal failure.

Additional images

• 
  The posterior surfaces of the kidneys, showing areas of relation to the parietes.
• 
  Renal artery
• 
  Renal artery
• 
  Renal artery
• 
  Renal artery

References

External links

• MedlinePlus Image 9818
• Anatomy photo:40:11-0105 at the SUNY Downstate Medical Center - "Posterior Abdominal Wall: Branches of the Abdominal Aorta"