Bassett Collection Large Image - Lane Medical Library, Stanford University Medical Center

For permissions information regarding the use of these images, please contact Drew Bourn at dbourn@stanford.edu

Dissection of ear from lateral aspect

Relation of left mastoid air cells to external auditory meatus

The auricle has been cut away and the mastoid air cells opened. In this specimen pneumatization extended well above the petrosquamous fissure (12).

1 .	Temporal fossa
2 .	Upper pointer: Auricular cartilage (cut across) Lower pointer: Skin of external acoustic meatus
3 .	Zygomatic process temporal bone (cut across)
4 .	Upper pointer: External acoustic meatus Lower pointer: Cartilaginous acoustic meatus (covered by membrane)
5 .	Upper pointer: Masseteric nerve Lower pointer: Articular disc of mandible
6 .	Auriculotemporal nerve
7 .	Upper pointer: Pterygoid venous plexus Lower pointer: Middle meningeal artery
8 .	Superficial temporal artery
9 .	Internal maxillary artery
10 .	Middle temporal artery
11 .	Dura mater exposed in dissected area of temporal bone
12 .	Petrosquamous fissure
13 .	Mastoid cells (opened)
14 .	Splenius capitis muscle (cut away)
15 .	Auricular branch vagus nerve (cut off)
16 .	Posterior auricular nerve
17 .	Upper pointer: Anastomotic branch auriculotemporal nerve with facial nerve Lower pointer: Facial nerve
18 .	Upper pointer: Mastoid process Lower pointer: Tendon of sternocleidomastoid muscle