CPOP

The External Ear Canal

•Skin over cartilaginous portion is thick and adherent

•Skin over bony canal is thin, sensitive to palpation and susceptible to trauma

AAO-HNS/F

Certificate Program for Otolaryngology Personnel Workshop

7

Function of the EAC

• Small role in sound amplification • Protects the tympanic membrane from injury: • Curved shape prevents direct entry Hair and cerumen trap foreign bodies (including bugs) • Epithelial migration makes the normal ear canal self-cleaning

AAO-HNS/F

Certificate Program for Otolaryngology Personnel Workshop

8

The Middle Ear

• Space bounded by the tympanic membrane and promontory • Contains ossicles (malleus, incus, stapes) • Access to cochlea (oval, round windows) • Eustachian tube anteriorly ventilates space

AAO-HNS/F

Certificate Program for Otolaryngology Personnel Workshop

9