254 NORMAL HISTOLOGY AND ORGANOGRAPHY. 



Medulla. 



Each suprarenal is invested in a fibrous capsule and 

 a liberal supply of fat. The capsule contains many 

 elastic fibers and some smooth muscle cells. 



The cortex shows a radial structure and has been 

 divided into three zones, which are not very well de- 

 fined. 



i . The zona glomerulosa, next to the capsule, con- 

 sists of a row of columnar epithelial cells folded in 

 such a way as to form oval bodies or elongated heads 

 separated by strands of connective tissue from the cap- 

 sule. The oval nuclei are in the middle of the cells. 



2. The zona 

 fasciculata makes 

 up the larger por- 

 tion of the cortex 

 and consists of 

 anastomosing col- 

 umns of epithelial 

 cells, a continua- 

 tion of the zona 

 glomerulosa. 

 Each column has two rows of polygonal cells that are 

 smaller than those of the glomerulae. 



3. The zona reticularis borders on the medulla. 

 Here the columns anastomose and freely interlace. 

 The cells resemble those of the fasciculata. Con- 

 nective tissue ramify between the columns, hence 

 the radial appearance of the cortex. 



The medulla is coarsely vascular. The cells are 

 smaller than those of the cortex and are grouped in 

 round or oval masses. These cells are finely gran- 

 ular, often pigmented, and stain a brown color. 



Hilu 



Fig. 194. Cross section of suprarenal gland 

 of man. 



