Interlobular arteries Interlobular arteries Interlobular arteries (or cortical radiate arteries or cortical radial arteries) are renal blood vessels given off at right angles from the side of the arcuate arteries looking toward the cortical substance. The interlobular arteries pass directly outward between the medullary rays to reach the fibrous tunic, where they end in the capillary network of this part. These vessels do not anastomose with each other, but form end-arteries. In their outward course, they give off lateral branches, which are the afferent arterioles that supply the renal corpuscles. The afferent arterioles, then, enter Bowman's capsule and end in the glomerulus.
Vein pressure. The arteries are perceived as carrying oxygenated blood to the tissues, while veins carry deoxygenated blood back to the heart. This is true of the systemic circulation, by far the larger of the two circuits of blood in the body, which transports oxygen from the heart to the tissues of the body. However, in pulmonary circulation, the arteries carry deoxygenated blood from the heart to the lungs, and veins return blood from the lungs to the heart. The difference between veins and arteries is their direction of flow (out of the heart by arteries, returning to the heart for