THE SKELETON 



51 



maxilla. This canal, beginning in a vertical groove, the naso- 

 lachrymal groove, carries the duct permitting the tears to pass 

 from the eye into the nasal chamber (Fig. 16). 



The malar bone is paired. It forms the cheek as well as 

 the lateral and cranial border of the orbit. The arch largely 

 formed by this bone is the zygoma. 

 The process projecting dorsad toward 

 the postorbital process of the frontal 

 bone is the postorbital process of the 

 malar. The masseter muscle origi- 

 nates on the border of the malar. 



The mandible or inferior maxillary 

 is the single bone forming the lower 

 jaw (Figs. 20 and 22). It is made 

 up of two halves which are united 

 by an immovable articulation or 

 symphysis at the chin. Each half 

 consists of a horizontal and an as- 

 cending ramus. On its alveolar 

 border the horizontal ramus bears 



• FlC" 2 1 \^F*NTRAI AsPKCT 



three incisor teeth, a canme, two ^^ larynx, Hyoid Bones, 

 premolars and a molar tooth. In and Tongue. 



^ . The tongue has been cut 



the caudal part of the medial SUr- transversely near its middle 



face of this ramus is the mandibular ryoid^retrL'rroved. ''= 

 foramen, which transmits the inferior- bh, Basihyai; ch, ceratohyai; 



^ . cr, cricoid cartilage of the 



alveolar nerve and artery traversmg larynx; eh, epihyai; ep. epi- 

 the mandibular canal 



within the bone to 



extending s^°"^^; i^' cricothyroid liga- 



^ ment; lyh, thyrohyal; rg, rings 

 the mental of cartilage of the trachea; tc. 



- .^ ^ . ^ r thyroid Cartilage of the larynx I 



foramen on the lateral surface near ^^^ tympanohyai; sh. styio- 

 the base of the canine tooth. The ^y^^- 

 space on the dorsal border between the canine and the first 

 premolar tooth is called the diastema. 



The ascending ramus or portion of the bone caudad of the 

 inferior tooth is marked by six features: (i) the fossa on the 

 outer or lateral surface which gives insertion to the masseter 



