22 4 



NORMAL HISTOLOGY. 



V ~ ~ -.."- ^__^ ' 



- -~" ; ^ "---' _ - _-~ 



Capsule 



Zona 

 omerulosa 



15-20/1 in diameter, whose cytoplasm lodges a variable, but usually large 

 number of fat granules. The latter are very abundant in the cells of the 

 zona fasciculata, but few or entirely absent in those of the zona reticularis. 

 Within the last named region, however, the cells are more or less pigmented, 

 a peculiarity accounting for the darker tint of this part of the cortex (Fig. 



_ 2 74)- The cells composing 



the cords and columns are 

 in direct contact with one 

 another; neither are they, as 

 groups, surrounded by a base- 

 ment membrane, but come 

 into close relation with the 

 capillary blood-vessels that 

 enclose the cell-islands, a few 

 delicate strands of supporting 

 .Capillary tissue alone intervening. 



The medullary sub- 

 stance consists chiefly of net- 

 works of anastomosing cords 

 of polyhedral cells ( 2030 /j. in 

 diameter), so prone to post- 

 mortem change that, as usu- 

 ally seen, they are very irreg- 

 ular and often stellate. They 

 are distinguished from the cor- 

 tical elements by the affinity 

 of their cytoplasm for chromic 

 acid and its salts, staining 

 yellow or brown. They are 

 known, therefore, as chromaf- 

 fin cells, and regarded as akin 

 to sympathetic elements. In 

 addition to these cells, the me- 

 dulla contains numerous blood- 

 vessels, particularly venous 

 channels, and many bundles 

 of nerve-fibres and ganglion- 

 cells. The latter (Fig. 275) 

 occur singly or in small groups, 

 are multipolar or stellate, and 

 resemble the cell-bodies of 

 sympathetic neurones. 



The blood-vessels sup- 

 plying the suprarenal body 

 divide into a dozen or more 

 fine branches which enter by 



Capillary 



Zona 

 reticularis 



Medulla 



FIG. 274. Section of suprarenal body, showing details of 

 superficial and deep portions of cortex. X 225. 



piercing the capsule at various points, some penetrating directly as far as the 

 medulla, but most of them terminating within the cortex. These last form 

 a superficial network from which the capillaries extend between the cell- 

 cords, which are thus enclosed within vascular meshes of corresponding form. 

 Thus, within the cortex the meshes are elongated and within the medulla of 

 rounded form. In large part the medulla is supplied by arterioles passing 

 directly to the interior of the organ. These break up into capillaries which 



