Blood flow through the Kidneys

The Kidneys receive about 25% of the blood flow from the heart through the renal arteries off the Abdominal Aorta. This is a very blood intensive organ because it filters the blood to take the waste out as urine and keep the nutrients, vitamins, salts, and minerals needed by the cells of the body. The blood enters the kidney through the Renal artery. It then branches into Segmental arteries which supply blood to different area's of the kidney. The Segmental arteries branch into Interlobar arteries which go in between the renal columns and pyramids. At the base of the renal pyramids the Interlobar arteries branch into Arcuate arteries that go between the medulla and cortex regions. The Arcuate arteries divide and become the Interlobular arteres that pass between renal lobules. Interlobular arteries continue into the cortex and branch into the Afferent arterioles which go into a Nephron and form a Glomerulus capillary network. The Glomerulus capillary network becomes the Efferent arterioles after they recombine. These Efferent arterioles split into the Peritubular capillaries which surround the tubule parts of the Nephron. The Peritubular capillaries merge into the Interlobular veins. This drains into the Arcuate veins to the Interlobar veins which pass the renal pyramids. The Interlobar veins come together to form the Renal vein that finally goes into the Inferior Vena Cava and back to the heart.

I found this slide show on the web that is pretty helpful in explaining how this works with pictures so all these words don't just run together and give you a head ache. There is even a nice little game to play at the end.
http://www.wisc-online.com/objects/AP2504/AP2504.swf