Splitting the kidney in half will reveal its internal anatomical structures, as shown.
The renal cortex is the solid-looking outermost part of the kidney. It contains many small arteries and veins that carry blood to and from approximatly one million nephrons located in the cortex.
The medulla is the region located inward from the cortex. It includes the cone-shaped renal pyramids. These are the fibrous or striped triangular zones in the medulla that contain the colleting ducts, which collect urine from the kidney tubules of the nephrons in the cortex. Between the pyramids are the renal columns that contain arteries and veins that carry blood between the nephrons in the cortex.
The hollow area in the center of the kidney is the renal pelvis, which should not be confused with the bone called the pelvis. The collecting ducts drain into the pelvis. From there, the urine passes out through the ureter and finally finds its way to the urinary bladder.