Inner ear anatomy / Labyrinths
Labyrinths
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The inner ear consists of 2 structural regions that contain different fluids: the bony (osseous) labyrinth, which contains Na+-rich perilymph, and the membranous labyrinth, which contains K+-rich endolymph. The histology in each of the 6 receptive areas of the inner ear is similar. |
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Black |
Osseous labyrinth |
| Grey | Perilymph |
| Dark blue | Membranous labyrinth |
| Light blue | Endolymph |
| Red | Receptive region |
| Green | Gelatinous mass |
- the inner ear can be divided into 2 structural regions:
- osseous (bony) labyrinth: a connected series of canals carved out of the temporal bone that contain perilymph
- perilymph is a normal extracellular fluid (high Na+, low K+)
- membranous labyrinth: tube suspended within the osseous labyrinth that contains endolymph
- endolymph is an unusual extracellular fluid (high K+, low Na+)
- osseous (bony) labyrinth: a connected series of canals carved out of the temporal bone that contain perilymph
- the areas containing the receptor (hair) cells lie within the membranous labyrinth, with a gelatinous matrix overlying their apical surfaces