CLINICAL ASPECTS OF ENDOCRINOLOGY 29 



the vegetative nervous system, because through it the 

 normal continuation of life and the vital functions are 

 preserved. On the other hand, the better known "sym- 

 pathetic nervous system" is that portion of the vegeta- 

 tive system which is represented by the gangliated 

 cord on either side of the spinal column, with its gang- 

 lia and communicating fibres, which might be termed 

 the "thoracic autonomic." The vegetative system 

 proper is divided into the midbrain, whose segments 

 pass by way of the oculomotor nerve pathways ; the bul- 

 bar, which through the facial, glossopharyngeal, and 

 vagus supplies the glands, vasodilators of the head, 

 heart, bronchi, esophagus, stomach, intestines and pan- 

 creas; and the sacral, which supplies the descending 

 colon, sigmoid, bladder, and genitals. 



Concerning these different divisions, the midbrain, 

 bulbar, and sacral are similar in that they are entirely 

 local in their supply; whereas the sympathetic or 

 "thoracic autonomic" not only has its local distribution, 

 but also it sends segments to the same structures as the 

 other system, thus causing the vegetative system to be 

 innervated by only one system. As examples of autono- 

 mic structure having a double supply one may men- 

 tion the salivary glands, gastric glands, intestinal mus- 

 culature, heart and blood vessels. Those having a sin- 

 gle or sympathetic supply are the smooth muscle of the 

 skin and the blood-vessels of the intestines, and the in- 

 ternal generative organs. 



As an example of the antagonistic action of the two 

 systems one may instance the external genitals. As an 

 example of double innervation of similar stimulating 

 effect, the salivary glands, in those nerves having a 

 vegetative activity, the efferent and afferent fibres are 

 interrupted in their course from the corticospinal sys- 

 tem by preganglionic and postganglionic segments, 

 with a variation in location from the sympathetic cord 

 to the submucosa of the intestines. This latter nerve 



