340 



THE DUCTLESS GLANDS 



[CH. XXV. 



the symptoms after extirpation will then be due to the toxic effect 

 of an accumulation of the poison. It has further been shown that 

 tetany produced in animals and men by parathyroidectomy can be 

 relieved by the administration of calcium salts, and so it is possible 

 that the parathyroids may be related in some way to calcium 

 metabolism. 



The Suprarenal Capsules. 



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

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



The gland is surrounded by an outer sheath of connective tissue, 

 which sends in fine prolongations forming the framework of the gland. 

 The gland tissue proper consists of an outside firmer cortical portion 

 and an inside soft, dark medullary portion. 



(1) The cortical portion is divided into (fig. 281) columnar groups 



FIG. 281. Vertical section through part of the cortical portion of suprarenal of guinea-pig, a, Cap- 

 sule ; b, zona glomerulosa ; c, zona fasciculata ; d, connective tissue supporting the columns of the 

 cells of the latter, and also indicating the position of the blood-vessels. (S. K. Alcock.) 



of cells (zona fasciculata). Immediately under the capsule, however, 

 the groups are more rounded (zona glomerulosa), while next to the 

 medulla they have a reticular arrangement (zona reticularis). The 

 cells themselves are polyhedral, each with a clear round nucleus, and 

 contain lipoid globules. 



(2) The medullary substance consists of a coarse rounded or 

 irregular meshwork of fibrous tissue, in the alveoli of which are 



