THE DYNAMICS OF ADRENAL FUNCTIONAL ACTIVITY. 29 



1. The functions of the adrenals are actively enhanced by 

 stimulation of the splanchnic nerve, and appear to be increased 

 in the same manner by poisons. 



2. The functions of the adrenals appear to undergo over- 

 stimulation when a sufficiently active toxic is present in the blood, 

 the result being either haemorrhage into the adrenals per se, or 

 inhibition of their functions. 



MECHANICAL PHENOMENA THAT ATTEND VARIATIONS IN 

 THE FUNCTIONAL ACTIVITY OF THE ADRENALS. 



In cases of suprarenal haemorrhage, as we have seen, two 

 entirely distinct forms of this condition prevail. The first of 

 these occurs when, after a destructive disease, the vestige of 

 medulla left suddenly ceases to secrete enough active principle 

 to continue the physiological functions over which the adrenals 

 preside. The second form is that due to general intoxication. 



The symptoms observed in these cases include the follow- 

 ing, which may be considered as standard signs: (1) extreme 

 weakness due to gradual decline of muscular power; (2) violent 

 abdominal pain; (3) great reduction of vascular pressure; (4) 

 subnormal temperature; (5) liquid stools; (6) scanty urine or 

 anuria; (7) syncope or convulsions the whole ending in death 

 in from 20 minutes to 3 days. The sudden annihilation of 

 suprarenal functions obviously involves cessation of secretion. 

 We have seen that the latter maintains the tone of the vascular 

 muscles; the first effect produced, therefore, is suddenly to 

 relax the entire vascular system, as shown by the marked re- 

 duction of vascular pressure. As a consequence, the great cen- 

 tral trunks the aorta, the vena cava, etc. become, by reason 

 of their size and their situation, the main centers of engorge- 

 ment: an assertion not only demonstrable by clinical signs, but 

 indirectly also by the experiments of Oliver and Schafer, who 

 found, by plethysmographic observations upon the limbs and 

 spleen, that injections of suprarenal extract produced great 

 vascular constriction chiefly in the splanchnic area. That ab- 

 sence of suprarenal secretion in the organism should produce 

 the opposite result in the same region is obvious. 



This central engorgement of suprarenal origin greatly 

 accentuated through the fact that "vessels supplied with a mus- 



