Bones of the Cranium. 



4. Sphenoid Bone, Os sphenoideum, from above. 



The sphenoid bone is divided into: 1. the body, 2. the wings; 

 the latter form 3 pairs: a) the lesser wings, Alae minor es : b) the 

 greater wings, A/ae maynae, and c) the wing like or pt cry go id 

 p r o c e s s e s, Processus pterygoidci. 



B o d y. On t h e u p p e r surface the pituitary fossa or 

 ticlld tnrcica (for the Hypophysis cereltri) ; its posterior wall, the Dorsum 

 sellae or eplitppii, with the posterior clinoid })rocesses, Proccssus clinoidci 

 2)f)*tici. The posterior surface of the Dor sum scllae is continuous with the 

 basilar groove of the occipital loone-Clivus. In front of the pituitary fossa 

 the Tuberculum cpltippii ; on both sides of this the middle clinoid processes. 

 On the lateral surfaces of the body the cavernous groove, Sulcus 

 caroticiix (for the C<irot!x) with the Linyula. 



Lesser wings; each arises from the body by 2 roots, between 

 which is the optic foramen; the ends looking toward the Dor sum scllae 

 form the anterior clinoid' processes, Proccsws clinoidci antcriorcs. 



Greater wings each with three surfaces and three borders. 

 The cerebral surface, Superficies cen'bralis, with the furrow for the 

 middle meningeal artery and vein. The inner segment of the upper 

 border forms with the lower surface of the lesser wing the sphenoidal 

 fissure, Fiszura splienoidalis (Fix*, orltitalis superior). The posterior border is 

 prolonged into the spinous process, tipina anc/ularix. The Foramen rotundum 

 (for the 2 nd division of the V. pair of cranial nerves) ; the Foramen 

 ova/c (for the 3 rd division of the V. pair) ; the Foramen spinosnnn (for 

 the middle meningeal artery). 



