• External ear
  • auricle
  • external auditory meatus
• Middle ear (or tympanum, tympanic cavity)
  • tympanic membrane
  • tympanic cavity & antrum
  • pharyngotympanic tube (or auditory tube, or Eustachian tube)
• Internal (inner) ear
  • osseous labyrinth
  • membranous labrynth

1. concha
2. crus helix
3. helix
4. scaphoid fossa
5. antihelix
6. antitragus
7. tragus

Middle ear The diagram shows a cut through the external, middle and inner ears. The middle ear cavity is like a small box with lateral, medial, anterior and posterior walls, a floor and a roof. This box is located inside the temporal bone. Items to identify are: mec-middle ear cavity ptb-temporal bone, eam-external auditory meatus, ec-ear cartilage, tm-tympanic membrane. Medial wall promontory with its tympanic plexus of nerves Lateral wall tympanic membrane (tm) Anterior wall pharyngotympanic tube (at) sulcus for internal carotid artery Posterior wall opening into mastoid air cells Roof tegmen tympani of petrous temporal bone ptb Floor sulcus for internal jugular vein (not shown)
Internal Ear The internal or inner ear is made up of an osseous part (ol) which encloses a membranous part (ml), in blue on the image. The membranous part includes the vestibule and semicircular canals for equilibrium and the cochlea for sound.
If visualizing the middle ear cavity in three dimensions is difficult, print out the following image and make the proper folds. The associated structures are listed and numbered.
Middle ear cavity canal for tensor tympani muscle auditory tube internal carotid artery facial nerve geniculate ganglion greater petrosal nerve lesser petrosal nerve promontory formed by 1st turn of cochlea tympanic plexus round window lateral semicircular canal facial canal and facial nerve oval window for stapes tympanic nerve from IX jugular vein opening to mastoid air cells (aditus ad antrum) tendon of stapedius muscle malleus tympanic membrane chorda tympani stylomastoid foramen