Sense organs (eye and ear)
Tympanic membrane
Membrana tympanica
- Origin
- Obliquely placed membrane at the end of the external acoustic meatus, between outer and middle ear
- Insertion
- Fixed in the fibrocartilaginous ring; the handle of the malleus is fused with it
- Function
- Converts air vibration into mechanical movement of the ossicular chain (pars tensa as the actual vibrating membrane, pars flaccida above)
- Innervation
- Outer surface auriculotemporal nerve (V3) and auricular branch of the vagus; inner surface tympanic nerve (IX, tympanic plexus)
- Movement & chain
- Vibrates with sound and moves visibly on Valsalva or pneumatic otoscopy
- Palpation
- Otoscopy: colour, light reflex, position of the malleus handle and translucency
- Clinical
- Acute otitis media (red, bulging drum), tympanic perforation, cholesteatoma in the pars flaccida, serous otitis media
- Segmental innervation
- Sensory V3, IX and X (vagal stimulation explains the urge to cough during ear cleaning)
- In clinical practice
- Never irrigate with a suspected perforation; discuss diving advice with grommets
- Region in the model
- Sense organs (eye and ear)