114 EQUINE ANATOMY. 



ioth, or Pneumogastric. 



Superficial Origin. Antero-lateral tract of medulla. 

 Deep Origin. Floor of fourth ventricle. 

 Exit. By posterior lacerated foramen, above carotid artery, to 

 front of thorax, dividing into bronchial and cesophageal. 



Branches. 



Communicating to eleventh, superior and inferior cervical 

 ganglia. 



Superior laryngeal, to mucous membrane of larynx and crico- 

 thyroid muscle. 



Inferior laryngeal, to all muscles of larynx except crico-thyroid. 



Bronchial, to bronchi and lungs. 



(Esophageal, to oesophagus, stomach, liver and solar plexus. 



nth, or Spinal Accessory. 



Superficial Origin. Lateral tract of medulla, along whole 

 cervical region of cord. 



Deep Origin. Fourth ventricle. 



Exit. Up through foramen magnum and foramen lacerum to 

 neck, and follows mastoideo-humeralis. 



Branches. 



To cervical sympathetic, sterno-maxillaris, mastoideo-humeralis, 

 cervical and dorsal trapezius and cervical nerves. 



1 2th, or Hypoglossal. 



Superficial Origin. Side of medulla near inferior spinal roots. 

 Deep Origin. From fourth ventricle. 

 Exit. Condyloid foramen. 



Branches. 



To muscles of tongue. 



SPINAL NERVES. 



They are 42 or 43 pairs that leave the spinal canal by the 

 intervertebral foramina. The superior or sensory roots have a 

 ganglion developed on them. The motor and sensory roots unite 

 and soon after divide into a superior branch to the spinal muscles 

 and integument, and an inferior to the lower part of the trunk 

 and extremities. Their relative number in the different regions 

 are cervical, 8; dorsal, 18; lumbar, 6; sacral, 5; coccygeal y 6 or 7. 



