170 RESPIRATION 



The efferent nerves of respiration control the muscular 

 movements of that act. They are chiefly the facial, hypo- 

 glossal and spinal accessory controlling the respiratory 

 movements about the face and throat, the pneumo gastric 

 going to the larynx and the phrenic to the diaphragm. 



To the lungs proper fibers are distributed by the vagus, 

 the dorsal sp.inal and the sympathetic nerves. Besides the 

 expiratory and inspiratory fibers already noticed, the vagus 

 supplies the lungs with broncho-motor, general sensory, tro- 

 phic and secretory (mucous) fibers. The sympathetic fur- 

 nishes trophic and vaso-motor fibers, which latter come from 

 the cord by the roots of the dorsal nerves mentioned to join 

 the sympathetic ganglia. 



