Henry Gray (18251861). Anatomy of the Human Body. 1918.
In their outward course they give off lateral branches; these are the afferent vessels for the renal corpuscles (see page 1221); they enter the capsule, and end in the glomerulus. From each tuft the corresponding efferent vessel arises, and, having made its egress from the capsule near to the point where the afferent vessel enters, breaks up into a number of branches, which form a dense plexus around the adjacent urinary tubes.
The second set of branches from the arterial arcades supply the renal pyramids, which they enter at their bases; and, passing straight through their substance to their apices, terminate in the venous plexuses found in that situation. They are called the arteriæ rectæ. The efferent vessels from the glomeruli nearest the medulla break up into leashes of straight vessels (false arteriæ rectæ) which pass down into the medulla and join the plexus of vessels there (Fig. 1128).
FIG. 1133 Transverse section of pyramidal substance of kidney of pig, the bloodvessels of which are injected. a. Large collecting tube, cut across, lined with cylindrical epithelium. b. Branch of collecting tube, cut across, lined with cubical epithelium. c, d. Henles loops cut across. e. Bloodvessels cut across. D. Connective tissue ground substance. (See enlarged image)
The renal veins arise from three sources, viz., the veins beneath the fibrous tunic, the plexuses around the convoluted tubules in the cortex, and the plexuses situated at the apices of the renal pyramids. The veins beneath the fibrous tunic (venæ stellatæ) are stellate in arrangement, and are derived from the capillary net-work, into which the terminal branches of the interlobular arteries break up. These join to form the interlobular veins, which pass inward between the rays, receive branches from the plexuses around the convoluted tubules, and, having arrived at the bases of the renal pyramids, join with the venæ rectæ, next to be described.