A         External ear

1          external auditory meatus (canal)

2          tympanic membrane (eardrum)

3          fibrocartilage annulus


B         Middle ear

4          tympanic cavity

5          site where auditory tube enters 4.

6          orifice of auditory (Eustachian) tube

7          malleus (hammer)

7a        head of malleus

7b        manubrium of malleus

7c        lateral process of malleus

8          incus (anvil)

8a        short crus of incus

8b        long crus of incus

9          stapes (stirrup)

9a        head of stapes

9b        anterior & posterior processes

9c        base of stapes

10        lentiform nodule of incus

11        chorda tympani (nerve fibers)

12        tensor tympani muscle


C         Inner ear (labyrinth)

13        vestibule

14        fenestra of vestibule

15        promontory

16        cochlear (round) window

17        lateral semicircular canal

17a      entrance (ampulla ossea lateralis)

18        superior semicircular canal

18b      entrance (ampulla ossea anterior)

19        posterior semicircular canal

19c      entrance (ampulla ossea posterior)

20        cochlea

21        auditory (vestibulocochlear) nerve

22        scala vestibuli

23        tympanic canal

24        cochlear duct

25        site of organ of Corti