170 



OSTEOLOGY. 



temporal fossa, whilst inferiorly it is continuous with the infra-maxillary region. 

 Medially, on the floor of the fossa there is an f -shaped fissure, the horizontal 

 limb of which corresponds to the inferior orbital fissure, forming a channel of 

 communication between the fossa and the orbit, through which passes the zygomatic 

 branch of the maxillary division of the trigeminal nerve ; whilst the vertical cleft is 

 the pterygo-maxillary fissure, which leads into a small fossa placed between the front 

 of the root of the pterygoid process of the sphenoid and the back of the maxilla, 

 called the pterygo-palatine fossa. 



The following foramina open into the infra-temporal fossa the foramen ovale, 

 foramen spinosum, foramina' alveolaria, mandibular foramen, minute foramina for 

 the transmission of emissary veins ; of these one of large size is occasionally 

 present, the foramen of Vesalius. 



Fossa Pterygopalatina. This space, which corresponds to the angular 



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24 23 22 



FIG. 170. FRONTAL SECTION THROUGH THE PTERYGO-PALATINE FOSSA OP THE RIGHT SIDE. 



The sphenoid is coloured red. The maxilla and vomer are coloured blue. The palate bone and 

 middle and inferior conchae are left uncoloured. 



A. Anterior Wall. B. Posterior Wall. C. Diagrammatic representation of a horizontal section across the 



1. Spheno-palatine foramen. 



2. Apex of orbital cavity. 



3. Inferior orbital fissure. 



4. Inferior orbital fissure. 



5. Pterygo-maxillary fissure. 



6. Alveolar foramina. 



7. Part of pterygoid fossa. 



fossa. 



8, 9, 10. Pterygo-palatine and 

 palatine canals. 



11. Foramen rotundum. 



12. Superior orbital fissure. 



13. Optic foramen. 



14. Sphenoidal sinus. 



15. Pharyngeal canal. 



16. Pterygoid canal. 



17. Spheno-palatine foramen. 



18. Pterygo-palatine fossa. 



19. Infra-orbital groove. 



20. Inferior orbital fissure. 



21. Pterygo-maxillary fissure. 



22. Foramen rotundum. 



23. Pterygoid canal. 



24. Pharyngeal canal. 



interval between the pterygo-maxillary and inferior orbital fissures, and which 

 lies between the maxilla in front and the root of the pterygoid process behind, 

 is bounded medially by the perpendicular part of the palate bone, which separates 

 it from .the nasal cavity, with which, however, it communicates by means of 

 the spheno-palatine foramen, which lies between the orbital and sphenoidal 

 processes of the palate bone and the inferior surface of the body of the sphenoid. 

 Opening into this fossa, above and behind, are the foramen rotundum, the 

 pterygoid canal and the pharyngeal canal, in that order from lateral to medial 

 side, whilst below is the superior orifice of the pterygo-palatine canal, together with 

 openings of the lesser palatine canals. Its roof is formed by the inferior surface of 

 the body of the sphenoid and the orbital process of the palate bone. Anteriorly 

 it lies in relation to the apex of the orbit, with which it communicates by means 

 of the inferior orbital fissure ; whilst laterally, as already stated, it communicates 

 with the infra-temporal fossa through the pterygo-maxillary fissure. 



