THE INNERVATION OF THE LUNGS. 



459 



contains all nerves that possess motor properties. The fol- 

 lowing list of the seven cranial nerves in the upper half of 

 the medulla will illustrate the relationship: 



1st pair. Olfactory: No motor function; no bulbar connec- 

 tion. 



2d pair. Optic: Filaments from 3d pair for iris and cil- 

 iary muscles. 



3d pair. Motor oculi: Filaments from corpora quadri- 

 gemina; supplies collateral fibers to oph- 

 thalmic ganglion for iris and ciliary muscles. 



4th pair. Patheticus: Fibers terminate in corpora quadri- 

 gemina; supplies fibers that govern superior 

 oblique muscle. 



5th pair. Trigeminal: Upper part of floor and anterior 

 wall of fourth ventricle. Small root of mas- 

 ticatory muscles. 



6th pair. Abducens: Upper part of floor of fourth ven- 

 tricle; supplies external rectus muscle. 



7th pair. Facial: Upper part of floor of fourth ventricle; 

 supplies levator palati, azygos uvulae, tensor 

 tympani, stapedius, and the external mus- 

 cles of the ear, face, etc. 



fc 



Again, all nerves that anastomose with motor fibers or 

 require them in addition to their own are in some way con- 

 nected with the fourth ventricle: 



9th pair. Glossopharyngeal : Lower part of fourth ven- 

 tricle. Supplies palatal and pharyngeal mus- 

 cles, through anastomosis. 



10th pair. Pneumogastric : Lower part of fourth ventricle. 

 Supplies oesophageal, cardiac, gastric, etc., 

 muscles, through anastomosis. 



llth pair. Spinal accessory: Lower part of fourth ventricle 

 and cord. Supplies laryngeal, deglutitory, 

 cardiac, and respiratory muscles. 



12th pair. Hypoglossal: Lowest portion of fourth ventricle. 

 Supplies lingual, masticatory, deglutitory, 

 etc., muscles. 



Still these only represent the motor nerves or motor anas- 

 tomoses. The t;asomotor connections are not referred to; but, 

 inasmuch as the vasomotor center has been experimentally 

 shown to be located in the medulla, it now behooves us to 

 account for the presence, besides the motor nerves just referred 



