556 



THE DUCTLESS GLANDS ENDOCRIN GLANDS 



circular muscle fibers are confined to a very thin coat beneath the endo- 

 thelium, or are often entirely absent. Frequently, and especially in the 

 central veins of the adrenal, the coarse bundles of longitudinal muscle 

 fibers project into the lumen of the vessel in a somewhat rugose manner. 

 Whenever two veins unite to form a larger vessel, and at the junction of 

 a central vein with any of its branches, these protuberant muscular 

 bundles are especially prominent. Moreover, Ferguson (Amer. Jour. 

 Anat., 5, 1, 1905) describes anomalous vessels of a venous nature which 



arise in the medulla, penetrate the 

 cortex, and enter the venous plexus 

 of the capsule; and in these in- 

 stances the same peculiar distribu- 

 tion of the muscle has? been observed 

 in the veins of the capsular plexus. 



"^BP%r f -|| j Lymphatics. The 1 lymphatics 



of the suprarenal gland, according 



j*ifc to Stilling (1887), form rich plex- 



uses in the zona glomerulo_sa and in 

 the medulla; elsewherethey are lessL. 

 abundant. They follow the course 

 of the blood-vessels and are espe- 

 cially well developed in the vicinity 

 of the central veinsT" 



Nerves. The adrenal is well 

 supplied with small sympathetic 

 nerve trunks from the_solar plexus. 

 They form a plexus in the capsule 

 from which branches are distributed 

 to the cortex and to the medulla. 

 In the cortex they invest the blood- 

 vessels with a delicate plexus, but have not been found within the epithe- 

 lisdcell columnar In the medulla they are also distributed to the blood- 

 vessels and are supplied with occasional small ganglia. Passing from 

 the plexus of sympathetic nerve fibers which invests the groups of medul- 

 lary epithelium, Dogiel (1894) demonstrated delicate fibrils, supplied 

 with minute varicosities, which penetrate between the epithelial cells and 

 terminate in a manner very similar to that which is characteristic of the 

 epithelial parenchyma of other secreting glands. 



Accessory Suprarenals. These include bodies of three types of 

 structure: (1) bodies consisting exclusively of cortical substance; (2) 





FIG. 482. SECTION OF PART OF AN AC- 

 CESSORY SUPRARENAL (CHROMO- 

 PHIL BODY), NEW-BORN CHILD. 



chr, a chromophil cell. (Sohafer, 

 " Quain's Anatomy.") 



