Cochlear duct

The cochlear duct (a.k.a. the scala media) is an endolymph filled cavity inside the cochlea, located between the tympanic duct and the vestibular duct, separated by the basilar membrane and the vestibular membrane (Reissner's membrane) respectively. The cochlear duct houses the organ of Corti.

Structure

The cochlear duct is part of the cochlea. It is separated from the tympanic duct (scala tympani) by the basilar membrane. It is separated from the vestibular duct (scala vestibuli) by the vestibular membrane (Reissner's membrane). The stria vascularis is located in the wall of the cochlear duct.

Development

The cochlear duct develops from the ventral otic vesicle (otocyst). It grows slightly flattened between the middle and outside of the body. This development may be regulated by the genes EYA1, SIX1, GATA3, and TBX1. The organ of Corti develops inside the cochlear duct.

Function

The cochlear duct contains the organ of Corti. This is attached to the basilar membrane. It also contains endolymph, which contains high concentrations of K⁺ for the function of inner hair cells and outer hair cells in the organ of Corti.

Clinical significance

Drugs delivered directly to the tympanic duct will spread to all of the cochlea except for the cochlear duct. Rarely, the cochlear duct may develop to have the wrong shape.

Additional images

References

External links

• Cross section at avatar.com.au

1. Cochlea
2. Stria vascularis of cochlear duct
3. Inner ear
4. Tympanic duct
5. Cochlear nerve
6. Vestibular duct
7. Cochlear
8. Ductus reuniens
9. Hair cell
10. Organ of Corti
11. Vestibular membrane
12. Auditory system
13. Endolymph
14. Human embryonic development
15. Ear
16. Crista ampullaris
17. Spiral ligament
18. Spiral ganglion
19. Stimulus (physiology)
20. Transthyretin