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,
Intersegmental artery Intersegmental artery The intersegmental arteries are a set of 30 arteries arising from the embryonic dorsal aorta, with each artery providing blood supply to one somite and its derivatives. The cervical intersegmental arteries merge into the vertebral artery with the exception of the 7th (or possibly the 6th) cervical intersegmental artery, which becomes the subclavian artery. The confusion arises because the vertebral artery drains into the subclavian artery following the disappearance of the dorsal aortae in part of the cervical region. The thoracic intersegmental arteries all develop into the intercostal arteries. The lumbar intersegmental arteries develop into the lumbar arteries,