THE SYMPATHETIC SYSTEM 287 



(a) A certain number of elements, physiologically 

 dependent on the spinal centres; 



(6) A certain number of elements, partially independent 

 of the spinal centres, real autonomous centres. We must 

 now study the grouping of the various components into 

 systems. Here anatomy is no longer of much help and we 

 must depend mostly upon physiology. For this reason 

 we are going to study jointly from a morphological and 

 physiological point of view each of the vegetative nerve 

 tracts. In studying these, we shall proceed from top to 

 bottom of the nerve axis, that is, from the cerebral peduncle 

 to the end of the spinal column. 



I. VEGETATIVE SYSTEM ARISING FROM THE 

 CEREBRAL PORTION. 



We remember that at the level of the cerebral peduncle, 

 we find a series of vegetative nuclei which are divided in 

 the following manner: 



In the cerebral peduncle a nucleus (pupillary) annexed 

 to the III cranial nerve. 



In the bulb, 6 nuclei, the first (lacrymal mucous-facial) 

 annexed to the facial, the second (superior salivary) an- 

 nexed to the intermediate, the third (inferior salivary) 

 annexed to the glosso pharyngeal, the fourth (vagus) and 

 the fifth (spinal) annexed to the vagus, the sixth (vaso 

 motor) annexed to the hypoglossal. 



A. PHYSIOLOGY OF THE VEGETATIVE SYSTEM OF THE III CRANIAL. 



The vegetative fibres arising from the pupillary nucleus 

 travel with the fibres of the III cranial up the ophthalmic 

 ganglion; they then abandon the oculo-motor and enter 

 the ganglion where they terminate and communicate 

 with the ganglionic cells. These ganglionic cells give 



