HEAD AND ANTERIOR CERVICAL STRUCTURES. 45 



Pterygo-palatine artery, or pterygo-pharyngeal : 



Pharyngeal. Eustachian. Sphenoidal. 

 Spheno-palatine, or naso-palatine artery : 



Pharyngeal branch. Sphenoidal branch.- Nasal branches. 



Ascending septal branches. 



With the chisel chip away the wall and expose the lachrymal sac and the nasal duct. 

 Lachrymal sac. Nasal duct. Lachrymal canal, 905-6. (884-5) 



With the chisel, chip away the anterior inferior wall of the carotid canal, and expose the intraosseous 

 portion of the internal carotid. 



Intraosseous portion, 529. (520) 



Branches of the intraosseous portion : 

 Tympanic. 

 Vidian branch. 



Middle Ear. Internal Ear. 



Remove the temporal bone, with the pinna. Cut away the squamous portion above the zygoma. With 

 a chisel, chip away the roof and anterior wall of the external auditory meatus, exposing the canal and 

 the outer surface of the membrana tympani. 



External Auditory Meatus, 909-10. (888-9) 

 Cartilaginous portion. 

 Osseous portion. 

 Lining membrane. 

 Arteries. 

 Nerves. 



Carefully chip away the tegmen tympani with a small, sharp chisel, and expose the tympanic cavity. 



The Middle Ear, 910-916. (889-894) 



Membrana tympani. Rivinian segment. Umbo. 



Structure : Fibrous layer, external and internal lamellae. 

 Cuticular covering. 

 Mucous lining. 

 Tympanic cavity: 



Roof. Floor. Outer wall. 



Chorda tympani nen>e, Iter chordae posterius,^Iter chordae anterius. 

 Inner wall : Fenestra ovalis, fenestra rotunda, Fallopian canal. 

 Fenestra ovalis. 

 Fenestra rotunda : 



Membrane of: Middle fibrous layer. 

 Mucous lining. 

 Serous layer. 

 Posterior wall. 

 Anterior wall. 

 Eustachian tube: 

 Osseous portion. 

 Cartilaginous portion. 

 Mucous membrane. 



Ossicles of the ear, 73-4-5. (85-6-7) 

 Malleus: 



Head. Neck. Handle, or manubrium. Slender process. Short process. 

 Incus : 



Body. Short process. Long process. Orbicular tubercle. 

 Stapes : 



Head. Base. Crura. Neck. 

 Articulation of the ossicles, 913, etc. (892, etc.) 



The malleus with the incus. Capsule. Meniscus. 

 Incus with the stapes. 



Elastic capsular ligament. 

 Stapes with the margin of the fenestra ovalis. 



