 This video will cover the following objective from the urinary system. Identify the major blood vessels associated with the kidney and trace the path of blood flow through the kidney. Blood flows into the kidneys through the renal arteries, that branch off from the abdominal aorta. Then the renal arteries will branch into segmental arteries and then the segmental arteries branch further to form interlobar arteries. Each interlobar artery carries blood into a lobe of the kidney and each interlobar artery travels in the renal columns in between the renal pyramids. Then the interlobar arteries branch to form arcuate arteries. The arcuate arteries are located at the border between the renal cortex and the renal medulla. Then the arcuate arteries give off numerous small branches called cortical radiate arteries. Cortical radiate arteries are also known as interlobular arteries, but I prefer the word cortical radiate artery to avoid confusion with the interlobar artery. Then the cortical radiate arteries, which are branching through the renal cortex, will carry blood towards smaller branches known as afferent arterioles. The afferent arterioles carry blood into a special capillary bed known as the glomerulus. The glomerulus is a fenestrated capillary bed where the process of filtration occurs. Filtration is the bulk flow of fluid out of the blood and this fluid is flowing into a system of tubes known as the nephron. The nephrons are the structural and functional units of the kidney that are responsible for producing urine and filtering the blood and processing the blood to regulate the composition of the blood. As blood flows from the afferent arterial into the glomerulus, some of the liquid is forced out of the blood across the glomerulus and flows into the nephron. The remaining blood will continue flowing out of the glomerulus into the afferent arterial. That's an unusual situation that we have two arterioles connected to a capillary bed. The afferent arterial carries blood into the glomerulus and the afferent arterial carries blood out of the glomerulus. Then the afferent arterial carries blood into another capillary bed known as the peritubular capillaries which are surrounding the tubules of the nephrons. Then blood will flow from the peritubular capillaries into venules that drain into the cortical radiate veins and arcuate veins. The arcuate veins then join together to drain into interlobar veins and the interlobar veins drain into segmental veins that then will come together to drain into the renal veins and the renal veins drain into the inferior vena cava.