Vessels of the kidneys

The kidney is very vascular. The larger arterial branches, : traced in section from the point at which they pierce the bottom of the sinus, will be found to run up between the pyramids of Malpighi to subdivide at that bases into cortico-medullary arches which lie between the cortex and medullar gigiving off arterioles in both directions, the cortical branches supplying afferent twigs to the glomeruli within the capsules of Bowman ; the medullary branches running inwards to form plexuses around the straight and looped tubules of the Malpighian pyramids. The efferent vessels of the Malpighian glomeruli form a capillary plexus around the uriniferous tubules and terminate in the renal veins. The surface of the kidney receives small collateral arteries which pass through the fatty capsule from the suprarenal, spermatic, and lumbar vessels. The superficial veins appear in the form of little stellate groups (stars of Verheyen), which are very distinct when the organ is congested. The renal lymphatics may be divided nto two sets, capsular and parenchymatous. They terminate in a series of glands lying with the renal vessels in the subperitoneal tissue, and their contents are ultimately conveyed into the receptaculum chyli.

Nerves of the kidneys

The nerves form a plexus accompanying the vessels, and are derived mainly from the sympathetic through the solar and aortic plexuses, the semilmiar ganglia, and the splanchnics. They communicate with the spermatic plexuses. Some filaments have also been traced from the pneumogastrics.