Cochlear Anatomy Flashcards
The cochlea is house where?
-Temporal bone of the cranium
What boney element surrounds the cochlea?
-Otic capsule
What are the types of temporal bone fractures? How often do they each occur? Which is worse?
- Longitudinal: 70%
- Transverse: 30%, worse
The cochlear has how many turns?
- 2.2-2.9 turns
- Average: 2.5 turns
How long is the average cochlea?
-35 mm
The central axis of the cochlea is called what?
-Modiolus
What is the function of the spiral lamina?
- Serves as a connection point for the BM
- Connects the spiral limbus to tectorial membrane
What are the two windows of the cochlea? Where are they located (which is superior)? What is
attached to them?
- Oval window: superior, attached to stapes footplate/scala vestibuli
- Round window: inferior, attached to scala tympani
What are the 3 scala and where are they located?
- Scala vestibuli: superior
- Scala media: middle
- Scala tympani: inferior
What divides the 3 scala and where are they located?
- Reissner’s membrane: divides scala vestibuli/media
- Basilar membrane: divides scala media/tympani
Describe the size and stiffness of the basilar membrane.
- Wide/thin/stiff at base
- Narrow/thick/flexible at apex
What is the main organ of hearing?
-Organ of Corti
What gelatinous flap of collagen lies above the organ of corti?
-Tectorial membrane
What is the purpose of the stria vascularis?
-Supplies blood (O2, K+) to the scala media to maintain the +80 mV resting potential of the endolymph
What are the two types of hair cells? What are their shapes? How many are there of each?
- OHCs: test-tube shaped, 12000
- IHCs: flask shaped, 3500
