This is a human cadaver temporal bone viewed from its superior surface after removal of the tegmen tympani (i.e., roof of middle ear) and opening the membranous labyrinth within the petrous portion of the temporal bone. The head of the malleus (m) and body of the incus (i) can be seen in the epitympanic recess. The lenticular process of the incus is seen articulating with the stapes head (s). Chorda tympani (ct) can be followed across the middle ear space from its entrance posteriorly to its exit anteriorly. The body of the tensor tympani muscle (ttm) is running in an anteromedial to posterolateral direction while its tendon ttt) is running in a medial-lateral direction to insert into the manubrium of the malleus. The tendon of the stapedius (ts) inserts into the stapes head posteriorly. Anteriorly, the middle ear space narrows to form the bony portion of the Eustachian tube (et). The vestibule (v) and cochlea (c) have been partially opened. Within the internal auditory meatus (IAM) the facial (VII) and vestibulocochlear (VIII) nerves are visible.
Plate modified from the companion slides with Vidic' and O'Rahilly, An Atlas of the Anatomy of the Ear, W. B. Saunders, 1971.