Question | Answer |
Sphenoid | Keystone of the cranial floor; forms its midportion; resembles a bat with wings outstretched and legs extended downward posteriorly; lies behind and slightly above the nose and throat; forms part of the floor and sidewalls of the orbit |
Body | Hollow, cubelike central portion |
Greater wings | Lateral projections from the body; form part of the outer wall of the orbit |
Lesser wings | Thin, triangular projections from the upper part of the sphenoid body; form the posterior part of the roof of the orbit |
Sella turcica | Saddle-shaped depression on the upper surface of the sphenoid body; contains, the pituitary gland; literally "turkish saddle" |
Sphenoid sinuses | Irregular mucosa-lined, air-filled spaces within the central part of the sphenoid |
Pterygoid processes | Downward projections on either side where the body and greater wing unite; comparable to the extended legs of a bat if the entire bone is likened to this animal; form part of the lateral nasal wall |
Optic foramen | Opening into the orbit at the root of the lesser wing; transmits the optic nerve |
Superior orbital fissure | Slitlike opening into the orbit; lateral to the optic foramen; transmits the third, fourth, and part of the fifth cranial nerves |
Foramen rotundum | Opening in the greater wing that transmits the maxillary division of the fifth cranial nerve |
Foramen ovale | Opening in the greater wing that transmits the mandibular division of the fifth cranial nerve |
Foramen lacerum | Opening at the junction of the sphenoid, temporal, and occipital bones; transmits a branch of the ascending pharyngeal artery |
Foramen spinosum | Opening in the greater wing that transmits the middle meningeal artery to supply the meninges |