160 



ELEMENTARY PHYSIOLOGY 



end (y, Fig. 49), connected with the spinal bulb be stimu- 

 lated, the respiration becomes hurried. Thus we have in 



Fig. 49. — Diagram to ilu'strate the Position of the Respiratory 

 Centre, the Connections of this Centre with the Intercostal 

 Muscles and Diaphragm, and the Paths by which Impulses pass 

 to the Centre from Outlying Parts of the Body and from 

 the Brain. 



Sp.C, Sp.C, spinal cord ; R.C, respiratory centre in the bulb ; JCN, ICN, 

 ICN, three intercostal nerves ; Phr. one phrenic nerve passing to the 

 diaphragm D; Vg. vagus nerve; V.G, ganglion of vagi.s nerve; S.Lr, 

 superior laryngeal nerve. The dotted lines, cf, cf, <•/, indicate paths of 

 conduction for impulses to the respiratory centre from some part of the 

 body such as the skin ; the dotted lines, af, a/, similar paths from the 

 brain to the centre. The arrows show the direction in which impulses 

 travel along each nerve or path. 



the vagns a nerve such that impulses passing up it may 

 quicken the respiration by their action on the respiratory 

 centre. 



