Eardrum
Membrana tympanica
Sensory (eye & ear)OrgansHeadLeft and right
View left in 3D View right in 3D
- What it is
- The eardrum: a thin, pearly-grey, cone-shaped membrane closing the inner end of the ear canal, its apex (the umbo) pulled inward by the attached handle of the malleus. It has three layers: outer skin, a middle fibrous layer and inner mucosa.
- Function
- Vibrates with incoming sound and passes the vibration to the ossicular chain.
- Size
- About 9-10 mm across and 0.1 mm thick, set obliquely at roughly 55 degrees to the canal floor.
- Clinical note
- Otoscopic landmarks are the malleus handle and the "cone of light" reflection in the antero-inferior quadrant; fluid in the middle ear makes the drum dull and bulging.