CIRCULATION 



255 



to the head are clamped or occluded ; (b) increased venosity 

 of the blood, as when respiration is interfered with ; (c} the 



FIG. 120. Connections of the Heart with the Central Nervous System. 

 Au., auricle ; V., ventricle ; V.D.C., abdominal vaso-dilator centre ; 

 0,1. C., cardiac inhibitory centre; C.A.C., cardio-augmentor centre; 

 S.C., superior cardiac branch of the vagus ; I.C., inferior cardiac branch 

 of the vagus with cell station in the heart ; S. , cardio-sympathetic fibres 

 with cell station in the lenticular ganglion ; V.D.Ab., vaso-dilator fibres 

 to abdominal vessels. The continuous lines are outgoing, the broken 

 lines are ingoing nerves. 



concurrent action of the respiratory centre (see p. 310). (2) 

 He/lex stimulation is produced through many nerves. In 



