7O INTERNAL SECRETION 



These results led Eppinger, Falta and Rudinger to the 

 conclusion that the thyroid and the chromaffine system, together 

 with, as Falta and Berterelli discovered later, the infundibular 

 portion of the hypophysis cerebri, constitute a group of vascular 

 glands which augment and accelerate the processes of metabolism. 

 The balance is maintained by the antagonistic activity of those 

 other vascular glands which, like the pancreas and the 

 parathyroids, exercise a retarding influence upon metabolism. 



Now as these two groups of internal secretory glands possess 

 physiological interrelationships with one another, the extirpation 

 of a vascular gland is followed by two different sets of phenomena. 

 In the first place, there are the direct results, due to suppression 

 of the specific secretion ; in the second, there are the indirect 

 results, due to derangement of other glands, the functions of 

 which, under normal conditions, were either stimulated or 

 inhibited by the activity of the suppressed gland. The thyroid is 

 believed to promote the activity of the chromaffine system and to 

 inhibit that of the pancreas. The direct results of thyroidectomy 

 consist in reduction in the metabolism of albumin, fat and salt. 

 The indirect results are, on the one hand, the absence of 

 stimulation of the chromaffine system, and on the other, a hyper- 

 activity of the pancreas due to the removal of the inhibitory agent. 



Eppinger, Falta and Rudinger believe that the nervous system 

 is the agent by which the interactivities of the vascular glands 

 are affected, and by means of which they are enabled to influence 

 the processes of metabolism. 



The relationship of these organs to the vegetative nervous 

 system is two-fold. In the first place, each gland is innerved by a 

 definite portion of the vegetative nervous system ; and in the 

 second, the internal secretion of each gland reacts upon the 

 condition of irritability of the nerve by which it is supplied. That 

 group of internal secretory organs which promotes metabolism has 

 a sympathetic innervation and stimulates the sympathetic nerves, 

 at the same time exercising an inhibitory effect upon the 

 autonomous nerves. The group which retards metabolism, on 

 the other hand, possesses an autonomous innervation and, while 

 stimulating the autonomous nerves, inhibits the sympathetic. 

 The thyroid gland possesses a double function ; being furnished 

 with both an autonomous and a sympathetic innervation, it is able 

 to affect both portions of the vegetative nervous system. 



The suppression of the thyroid is followed by a decreased 

 irritability of the sympathetic nerve, and this is manifested in a 

 sluggishness of the circulation and in certain trophic disturbances. 

 Adrenalin exercises a direct influence upon the sympathetic nerve, 

 but, after thyroidectomy, its exhibition is not followed by 

 glycosuria and it provokes only an inconsiderable rise in blood- 

 pressure. At the same time, the athyrosis produces a decreased 

 excitability of the autonomous nerves, as shown in the sluggish- 



