488 



HUMAN ANATOMY. 



7. Buccinator (Fig. 502). 



Bucco-Pharyngeal Fascia. — The buccinator alone of the platysma group of 

 muscles is covered by a distinct layer of fascia which forms the anterior part of the 

 fascia buccopharyngea and is a dense, resistant sheet of connective tissue intimately 



Fig. 502. 



■^m 



Temporal 



Tensor palati 



Levator palati 



Styloid process 



Hamular process 



Digastric, posterior belly, 



Superior constrictor 



Stylo-glossus 

 Pterygo-mandibular ligament 



Stylo-phyaryngeus 

 Stylo-hyoid 



Mandible (cut) 



Hyo-glossus 



Greater hyoid cornu 



Middle constrictor 



Thyro-hyoid 

 Inferior constrictor 



Corrugator supercilii 



Orbic. palp., palpebral part 



Pyramidalis nasi 



Orbic. palp., orbital part 

 Lev. labii sup. al. nasi (cut) 

 Levator labii superioris (cut) 



^ Compressor nanum 

 Levator anguli oris 

 Zygomaticus 



Buccinator 

 Orbicularis oris 



Depressor labii inferiorls 



Levator menti 



Platysma 



Oral, pharyngeal, and styloid groups of muscles ; part of mandible has been removed to show deeper structures. 



adherent to the outer surface of the muscle. Anteriorly the fascia thins out to disap- 

 pear in the tissue of the lips ; above it is attached to the alveolar portion of the 

 maxilla and to the internal pterygoid plate of the sphenoid, and thence is continued 



backward over the superior con- 

 FiG. 503. strictor muscle of the pharynx 



to meet with its fellow of the 

 opposite side behind the phar- 

 ynx ; below it is attached to the 

 posterior part of themylo-hyoid 

 ridge of the mandible. Along 

 a line which descends vertically 

 from the tip of the hamulus of 

 the sphenoid to the posterior 

 extremity of the mylo-hyoid 

 ridge of the mandible the fascia 

 is greatly thickened, forming 

 the pterygo-mandibular liga- 

 ment, from which fibres of the 

 buccinator arise anteriorly, while 

 posteriorlv it gives origin to a 

 portion of the superior constric- 

 tor of the pharynx. 



Attachments. — The buc- 

 cinator forms a thick quadrilateral muscle lying immediately exterior to .the mucous 

 membrane of the cheek. Its line of origin is horseshoe-shaped, extending above 

 along the alveolar border and tuberosity of the maxilla and thence upon the hamulus 



Levator anguli oris 



Buccinator 



Depressor anguli oris 



Diagram showing course oi component fibres forming 

 orbicularis oris muscle. 



