HISTOLOGY 



chromaffine cells forming a small inner medullary portion of the supra- 

 renal body, while the cortex substance forms, as its name implies, an 



outer cortical part (Fig. 284). 

 The cells of both cortex and 

 medulla form irregular cords, 

 and many sympathetic nerve 

 cells are found at a hilum in 

 contact with the medulla. 

 The cords of cortex cells are 

 extended radially from the 

 contact with the medulla to 

 the periphery of the organ. 

 The blood supply is carried 

 between the cords by wide, 

 irregular capillaries or sinus- 

 oids. A more internal por- 

 tion of the cortical cords is 

 slightly different in arrange- 

 ment, and forms an interme- 

 diate zone. The medulla 

 varies in amount and does 

 not extend into some of the 

 smaller lobes, which are thus 



composed of cortex alone. 



Another gland which is 

 treated of here, because its 

 function is not understood 

 and because it has no duct, 

 is the coccygeal gland of man. This gland may be dissected out as a 

 closely associated series of larger and smaller masses of dense yellowish 

 tissue, surrounding and adhering to the branches of the sacral artery. 



A section of one of these masses (Fig. 285) shows that it is composed 

 of several layers of the specific cells of the gland, adhering to the very thin 

 walls of a wide blood space that receives blood from a small branch of 

 the sacral artery. This blood space, or sinus, empties the blood through 

 many fine vessels which pass distally through the gland-cell layers and 

 collect the blood to deliver it into a neighboring vein. 



The cells, as shown by their size, more compact and deeper staining 

 cytoplasm, and their large nuclei, are evidently gland cells or secreting 

 cells. They are not arranged so as to have any neighboring lumen 

 and therefore must return their elaborated materials to the blood. Their 

 portion with reference to the blood supply is accentuated by the very thin 

 wall of the blood spaces or sinuses as well as by the fact that the blood 



ch. c. 



FIG. 284. Section through cortex and a small part of 

 medulla of the adrenal gland of a mole, ch.c., chro- 

 maffine cells of medulla; cor., cortex. X 500. 



