Renal artery

The renal arteries are two large arteries that arise from the side of the abdominal aorta, immediately below the superior mesenteric artery.

Each renal artery is directed across the crus of the diaphragm, so as to form nearly a right angle with the aorta.

The right renal artery is longer than the left renal artery, on account of the position of the aorta.

The right renal artery passes behind the inferior vena cava, the right renal vein, the head of the pancreas, and the descending part of the duodenum.

The left renal artery, is somewhat higher than the right; it lies behind the left renal vein, the body of the pancreas and the splenic vein, and is crossed by the inferior mesenteric vein.

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

Each renal artery 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, more especially on the left side they usually arise from the aorta, and may come off above or below the main artery, the former being the more common position. Instead of entering the kidney at the hilus, they usually pierce the upper or lower part of the gland.