The blood supply to the splenic lymphatic nodules in the rhesus monkey.

The arterioles and capillaries supplying the lymphatic nodules and marginal zone (in part) in the rhesus monkey's spleen arise from a follicular artery branch of the central artery. This follicular artery first undergoes a series of convolutions and branchings, out of which a parallel array of tightly bound arterioles and capillaries, an arteriolar capillary bundle (ACB), leading into the central part of the nodule is formed. From the proximal end, side, and distal end of the ACB, arterioles and capillaries radiate outward through the mantle zone of the nodule to terminate in the marginal zone. Some capillaries are formed within the bundle and others not until an arteriole nearly reaches the marginal zone. A similar ACB and capillary distribution is found in the human spleen. However, the supplying arteries, for the most part, come from recurrent penicillar arteries which pass close to the central artery before forming the bundle. This artery does not undergo the convolutions found in the rhesus monkey. In the monkey, the bundle contains a higher proportion of arteriolar vessels. It appears that in human and rhesus monkey spleens, the ACB replaces the internal capillary net of Jäger ('29).