THE CIRCULATION. 



267 



Fig. 84. Schema of Innervation of the Heart of a Dog. (MoRAT. ) 



gg.ca, Cardiac ganglia in which the cardiac nerves terminate, gg.ci, Inferior 

 cervical ganglion, gg.cs, Superior cervical ganglion, gg.pl, Plexiform ganglion. 

 sym.th, Thoracic sympathetic, an. VI, Ansa Vieussenii. pn.g, Pneumogastric. 

 n.ve, Vertebral nerve. Vag. syrup., Vago-sympathetic. sym.c, Cervical sympa- 

 thetic, sym.cr, Prolongation of the sympathetic in the skull. C 1 , First cervical 

 pair. D 1 , First dorsal pair. X, Origin of the pueumogastric. XI, Bulbar origin 

 of the spinal accessory. 



Porter and Beyer have shown that it dilates the arterioles 

 throughout the body, and especially those blood-vessels innervated by 

 the splanchnics. Excessive repletion of the heart stimulates the 

 endings of the depressor nerve in the heart. These afferent impulses 



