CH. XXIII.] 



SUPRA-RENAL CAPSULES. 



333 



supplies something which is a stimulator of metabolic processes, 

 and that the action on the nervous system is more especially the 

 work of the parathyroids. 



The Supra-renal Capsules. 



These are two triangular or cocked-hat-shaped bodies, each 



resting by its lower border upon the upper border of the kidney. 



Structure. The gland is surrounded by an outer sheath of con- 



-sr I* 





. 





. o 



9 



Fig. ;,o6. Vertical aection through part of the cortical portion of supra-renal of guinea-pig, 

 a, capsule ; ft, zona glomerufosa ; c, zona fasciculata ; <l, connective-tissue supporting 

 the columns of the cells of the latter, and also indicating the position of the blood- 

 vewelM. (8. K. Alcock.) 



nective-tissue, which sends in fine prolongations forming the frame- 

 work of the gland. The gland tissue proper consists of an outside 

 firmer cortical portion and an inside soft, dark medullary portion, 

 (i.) The cortical portion is divided into (fig. 306) columnar 

 groups of cells (zone fasciculate,). Immediately under the capsule, 

 however, the groups are more rounded (zona glomendosa), while 

 next to the medulla they have a reticular arrangement (zona 

 reticularis). The cells themselves are polyhedral, each with a 

 clear round nucleus, and often with oil globules in their proto- 

 plasm. The blood-vessels nm in the fibrous septa l>etween the 

 columns, but do not penetrate between the cells. 



