Blood flows to the kidneys through the right and left renal arteries. Inside each kidney these branch into smaller arterioles.
The blood is at very high pressure and flows through the arterioles into tiny knot of vessels called the Glomerulus. These are located in the nephrons.
From the glomerulus the blood pressure drops and the blood flows into arterioles which coil around the nephrons. These in turn connect to a series of small veins. These vessels reunite and ultimately form the renal vein.
About one quarter of the total cardiac output (or total blood flow) circulates through the kidneys. This equates to just over 1 litre of blood every minute.
