Kidney a minor calyx; minor calyces empty into major calyces, and major calyces empty into the renal pelvis. This becomes the ureter. At the hilum, the ureter and renal vein exit the kidney and the renal artery enters. Hilar fat and lymphatic tissue with lymph nodes surrounds these structures. The hilar fat is contiguous with a fat-filled cavity called the renal sinus. The renal sinus collectively contains the renal pelvis and calyces and separates these structures from the renal medullary tissue. The kidneys possess no overtly moving structures. The renal circulation supplies the blood to the kidneys via the renal arteries,
Celiac artery cannot be safely ligated in a living person, and obstruction of the celiac artery will lead to necrosis of the structures it supplies. The celiac artery is the only major artery that nourishes the abdominal digestive organs that does "not" have a similarly named vein. Most blood returning from the digestive organs (including from the area of distribution of the celiac artery) is diverted to the liver via the portal venous system for further processing and detoxification in the liver before returning to the systemic circulation via the hepatic veins. In contrast to the drainage of midgut and hindgut structures