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,
Perineal artery Perineal artery The perineal artery (superficial perineal artery) arises from the internal pudendal artery, and turns upward, crossing either over or under the superficial transverse perineal muscle, and runs forward, parallel to the pubic arch, in the interspace between the bulbocavernosus and ischiocavernosus muscles, both of which it supplies, and finally divides into several posterior scrotal branches which are distributed to the skin and dartos tunic of the scrotum. As it crosses the superficial transverse perineal muscle it gives off the "transverse perineal artery" which runs transversely on the cutaneous surface of the muscle, and anastomoses with the corresponding vessel