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PHYSIOLOGY. 



THE ADRENALS. 



The adrenals are a pair of flattened triangular organs, one being 

 situated upon the upper end of each kidney and inclined inwardly 

 toward the vertebral column. Their posterior surface, moderately 

 convex, rests against the crura of the diaphragm; their anterior sur- 

 face, flatter than the posterior, on the right side is in contact with 

 the liver, on the left side with the pancreas and spleen. The sur- 

 faces present vascular furrows, the largest of which at the base is 



Fig. 150. Section of Adrenal (VIALLETOX.) 



1, Fibrous capsule. 

 4, Zona reticularis. [ 



2, Zona glomerulosa. 3, Zona fasciculata. 

 Medulla. 6, Blood-vessel. 7, Central vein. 



distinguished as the hilus. These adrenals are brownish-yellow in 

 color, of moderately firm consistence, and vary in size in different 

 individuals and slightly on the two sides. Usually they are about 

 one and one-half inches in breadth and height, and about one-fourth 

 of an inch in thickness. On section we find an external layer, the 

 cortex, and an internal layer of softer substance, the medulla. 



The cortical layer is yellow in color, of firm consistence, and pre- 

 sents a columnar appearance at right angles to the surfaces of the layer. 

 Microscopically, it contains obiong receptacles occupying a fibrous 

 stroma continuous with the fibrous coat of the body. In these recep- 



