548 



PHYSIOLOGY 



CHAP. 



but by opening lively into the labyrinthine spaces of the splenic 

 reticulum. From the same reticulum the roots of the small veins 

 (see Fig. 260) arise by an opposite process and then open into 

 those which course along the trabeculae. 



The lymphatics of the spleen form plexuses in the. capsule and 

 in the trabeculae. They are not very numerous, and run with 

 the arteries, sometimes surrounding them, to form a plexus. The 

 perivascular adenoid tissue and the follicles composed of the 

 Malpighian nodules communicate with the lymphatic vessels with 



Fi<.. 2fr2. Section of Malpighian corpuscle and surrounding tissue of splenic pulp, with injected 

 network of blood capillaries, treated with silver chromate ; highly magnified. (Oppel.) 1, 

 Malpighian corpuscle ; 2, part of its reticulum ; 3, denser reticulum at the edge of the 

 corpuscle ; 4, looser tissue external to, the former ; 5, 0, connective tissue of arterial sheath, 

 to which the corpuscle is adhering ; 7, capillaries of corpuscle ; 8, reticulum of pulp surround- 

 ing the arteriole. 



proper walls that run in the tissue of the trabeculae. All the 

 lymphatics issue from the hilum together with the blood-vessels, 

 and then join the lymphatic ganglia of the posterior part of the 

 abdomen. 



The nerves of the spleen are derived from the solar plexus ; 

 they enter by the hilum along with the vessels. They are certainly 

 in peripheral relation both with the muscle cells of the vessels and 

 with those of the capsule and trabeculae. Their central origin is 

 probably in the bulb and cervical tract of the spinal cord. In 

 order to reach the periphery, the splenic nerves pass by the left 



