SUPPORT, MOTION, AND SENSATION 



355 



system, and since each of these centers usually presents a fanlikc 

 arrangement of efferent fibers, they serve to increase the number of 

 available pathways. 



The autonomic system is full of contradictions, for there appears to 

 be an antagonistic action on the part of the thoracicolumbar to 



ciiiar 



' sphsno gcJotirg g>T^lacrimal gland 



1 \xxmhar 



i Sacral 



Submaxillary^^^ "osa . palctta. 



■i^-2fe^^i^ subling,ual ^. 



mucous rtiem. 

 ■mouth. 



panoticC glancC 

 hacwrC 



louynx 

 trcLchao. 

 ^hronchtcs 



^vsssds of abcL 



liver and. 

 dLucts 



^^ pancrsQ-S 



fjcxdcmna-l 



Smail . 

 intestine 



Colo 



in. 



rectum 



Serf, or^n 



e)t±ernal 

 genitalia. 



Diagram of the autonomic nervous system. The parasympathetic part appears 

 in solid lines and the thoracicolumbar part in dotted hues. 



impulses from the cranial or sacral parts of the parasympathetic 

 system. Thus the cranial part slows the heart while the thoracicolum- 

 bar accelerates it. This has often been spoken of as "reciprocal 

 innervation, " a principle which plays a very important role in the 

 proper functioning of various organs. 



