LIGAMENTS AND MUSCLES OF THE HORSE. 33 



Zygoma Ticus. 



Origin. — From the surface of the masseter muscle. 

 Insertion. — To the buccinator muscle just above the angle of 



the mouth. 

 Action. — To raise the angle of the mouth. 

 Levator Labii Superioris Proprius (nasalis longus.) 

 Origin. — From the malar and superior maxillary bones below 



the orbit. 

 Insertion. — To the upper lip. 

 Action. — Together, they elevate the lip ; separately, raise and 



draw it to the side of the muscle acting. 

 Depressor Labii Inferioris. 

 Origin. — Yroxn. the edge of ramus of inferior maxilla behind 



last molar tooth. 

 Insertion. — To the lower lip. 

 Action. — To retract lower lip. 

 Levator Menti (Levator labii inferioris.) 

 Origin. —From the inferior maxilla below the intermediate and 



corner incisors, and as far back as the canine. 

 Insertion.— \t mixes with orbicularis oris, and forms the pro- 

 minence of the chin. 

 Action. —To raise the lower lip. 

 Buccinator. 

 Attachments. — To the superior maxilla from the alveolus of the 



canine tooth, back to the alveolar tuberosity ; in a similar 



manner to the inferior maxilla ; anteriorily blending its 



fibres with those of the orbicularis oris. 

 Action. — Principally to press the food between the teeth : but 



it may also retract the angle of the mouth. 

 Levator Labii Superioris Al.eque Nasi. 

 Origin. — From the frontal and nasal bones. 

 I insertion. — To the nostril and upper lip. 

 Action. — To dilate the nostril and raise the upper lip. 



