In the kidneys, blood drains through a specific pathway to eventually reach the interlobar veins. This process begins with blood entering the kidneys through the renal artery, branching into smaller arteries and arterioles. After filtration within the glomeruli, blood flows through the peritubular capillaries, which surround the nephron tubules. Deoxygenated blood then moves into the interlobular veins, which merge to form the larger interlobar veins. These interlobar veins ultimately connect to the renal vein, which carries the blood out of the kidney and back into the systemic circulation.