THE SYMPATHETIC AND PARASYMPATHETIC SYSTEMS 631 



that the motor units of the autonomic system are moulded into an 

 array of end-organs presenting a most perplexing structural and of 

 functional diversity. Naturally, all of them are concerned with vege- 

 tative processes and as such give rise to movements as well as to se- 

 cretions. The former embrace the musculomotor effects along the 

 alimentary and urinary tracts, the vasomotor and pilomotor actions, 

 the movements of the iris, and others. It would lead us altogether too 

 far to discuss these different autonomic functions in detail; many of 

 them, in fact, we have become acquainted with in the course of our 

 studies upon respiration, the circulation of the blood and reflex action. 

 For this reason, we shall confine ourselves at this time to a more 

 general summary, such as the following: 



A. The Cranial or Parasympathetic System. 



(a) The region of the midbrain. These fibers pass through the nervus oculo- 

 motorius and end in the gangl. ciliare. Motor fibers are sent to the muse, 

 sphincter pupillae and muse, ciliaris. 



(&) The region of the bulb. (1) The facial nerve conveys fibers to the gangl. 

 sphenopalatinum (nerv. petrosus superfic. major), whence they gain the 

 mucous membrane of the nose, palate and upper pharynx as well as the 

 lacrimal, submaxillary and sublingual glands. They are vasomotor and 

 secretomotor in their function. (2) The glossopharyngeus contains fibers 

 for the gangl. oticum (nerv. tympanicus et nerv. petrosus superf. minor), 

 whence they gain the parotid gland. They are vasodilator and secreto- 

 motor in their function. (3) The vagus nerve embraces inhibitor fibers for 

 the heart, motor fibers for the musculature of the bronchi, esophagus, 

 stomach and intestine, and secretomotor fibers for the glands of the stomach 

 and pancreas. 



B. The Cervical Sympathetic System. 



1. Musculomotor fibers for the muse, dilator pupillae and the smooth muscle tis- 

 sue of the orbits and eyelids. 



2. Vasomotor fibers for the blood-vessels of the ears, face, conjunctiva, iris, 

 choroidea, salivary glands, esophagus, larynx, thyroid, and brain. 



3. Secretomotor fibers for the sweat glands of the head region, and the salivary 

 and lacrimal glands. 



C. The Thoracic Sympathetic System. 



(a) Vertebral ganglia : 



1. Vasomotor fibers for the skin of the trunk and extremities. 



2. Pilomotor fibers for the same regions. 



3. Secretomotor fibers for the sweat glands of the same areas. 



(b) Thoracic and abdominal ganglia: 



1. Musculomotor fibers for the heart (gangl. stellatum). 



2. Vasomotor fibers for the abdominal viscera (splanchnic system and solar 

 ganglia). 



3. Vasomotor fibers for the colon descendens, rectum, bladder and uterus 

 (gangl. mesent. inf. and nerv. hypogastrici). 



D. The Sacral Sympathetic System (Parasympathetic in Character). 



1. Musculomotor fibers for the colon descendens, rectum, bladder and 

 genital organs. 



The Connections between the Cerebro spinal and Autonomic 

 Systems. Inasmuch as the vegetative processes are under the 

 direct control of the autonomic system, it must be evident that those 

 impulses which are relegated to this system from the brain and cord, 



