226 



NORMAL HISTOLOGY. 



uterus, in the vicinity of the ovary, is known as Marchand" s organ, and 

 regarded as a normal and almost constant organ. These ' ' accessory ' ' bodies 

 include two groups of different origin and morphological significance. Those 



associated in position with the chief organ, 

 as when in the liver or kidney, are derived 

 from separated and isolated portions of 

 t ^ ie P rmc 'P a l embryonic area of the supra- 

 renal and, therefore, are supernumerary. 

 The bodies situated in the broad ligament, 

 or in relation with the epididymis, are, 

 on the contrary, probably developed 

 from the atrophic tubules of the Wolffian 

 body and, hence, must be regarded as 

 structures independent of the main supra- 

 renal. The independent bodies never, 

 and the supernumerary ones only in very 

 exceptional cases, possess more than corti- 

 cal substance, a medulla being wanting. 



The suprarenal bodies are conceded 

 membership in the group of viscera now 

 termed organs of internal secretion. The 

 other members of this group are the thy- 

 roid, the parathyroids, the anterior lobe of 

 the pituitary and, perhaps, the thymus. 

 The specialized areas within the pancreas, 

 the islands of Langerhans, are also re- 

 garded as producing a particular sub- 

 stance and, hence, are minute organs of 

 internal secretion. That the substances 

 elaborated within these viscera are of im- 

 portance is evident from the fact that re- 

 moval of either the suprarenals, the para- 

 thyroids, or the pituitary results in death. 

 Although at present the role of the cor- 

 is disputed, the special activity t>f its 

 Adrenalin seemingly 



FIG. 276. Section of injected suprarenal 

 body ; the vessels in the lower third of figure 

 are chiefly tributary' to the central vein. X *5- 



tical substance of the suprarenal 



medulla in producing adrenalin seems established. 



exerts its influence especially upon the muscle of the blood vessels and, when 



present in the blood even in slight excess, causes unusual contraction of the 



arterial walls. 



