Inner Ear-Cochlea

Longitudinal section of a human cochlea.

1 Scala tympani (contains perilymph)

2 Cochlear duct (contains endolymph), triangular in cross-sections

3 Scala vestibuli (contains perilymph)

4 Osseous spiral lamina

5 Helicotrema (scala vestibuli and scala tympani join)

6 Cecum cupulare (copular blind sac, caecum cupulare)

7 Modiolus (end of the osseous spiral lamina)

8 Cochlear cupola (azimuth of the apical cochlear turn)

9 Longitudinal canals of the modioli (canales longitudinales modioli), central inner canals of the cochlea

10 Spiral canal of the modioli (canalis spiralis modioli), canal in the outer wall of the osseous spiral lamina

11 Facial nerve in the bony facial canal

12 Vestibular membrane (Reissner’s membrane, membrana vestibularis, upper wall of the cochlea)

13 Spiral crest, spiral ligament (ligamentum spirale cochlea)

14 Basilar membrane (connective tissue between cochlear duct and scala tympani)

15 Osseous spiral lamina

16 Area of the facial nerve of the internal acoustic meatus (fundus)

17 Cochlear ganglion (cochlear nerve)

18 Transverse crest

19 Base of the modiolus (base of the cochlea)

20 Cochlear ner ve

21 Internal acoustic meatus (fundus)

22 Spiral canal of the modioli Stain: hematoxylin-eosin; magnification: × 10

Cochlea—Inner Ear

Middle b end of the cochlea.

1 Cochlear duct (contains endolymph)

2 Spiral ligament, spiral crest

3 Stria vascularis, vascularized tissue over the spiral prominence

4 Reissner’s membrane, vestibular membrane

5 Scala vestibuli

6 Osseous spiral lamina

7 Cochlear ganglion

8 Spiral canal of the modioli (bony canal in the outer wall of the osseous spiral lamina)

9 Longitudinal canal of the modioli (central inner canal)

10 Tractus spiralis foraminosus, a few spirally arranged openings around the inner cochlear

canal, which permit access of cochlear nerve ganglia to the cochlea

11 Cochlear nerve (branch of the vestibulocochlear nerve for the cochlear audiosensory organ)

12 Internal acoustic meatus (fundus)

13 Scala tympani (contains perilymph)

14 Organ of Corti

15 Basilar membrane (connective tissue layer between cochlear duct and scala tympani)

Stain: hematoxylin-eosin; magnification: × 25

Cochlea—Inner Ear

Section of the cochlear duct from the apical turn of the cochlea with theorgan of Corti ( organum spirale).

1 Spiral ligament, spiral crest

2 External spiral groove of the cochlear duct

3 Spiral prominence (border of the external spiral groove)

4 Stria vascularis

5 Bony wall of the cochlea

6 Cochlear duct

7 Vestibular membrane, Reissner’s membrane

8 Scala vestibuli

9 Cochlear nerve

10 Scala tympani

11 Tectorial membrane (located over the organ of Corti and the inner cochlear canal)

12 Inner cochlear canal (canalis spiralis cochleae)

13 Inner hair cells

14 Inner tunnel, contains endolymph

15 Outer hair cells

16 Cells of Henson

17 Cells of Claudius

18 Basilar membrane

Stain: hematoxylin-eosin; magnification: × 80

References

Kuehnel, W.(2003). Color Atlas of Cytology, Histology, and Microscopic Anatomy. 4^th edition . Institute of Anatomy Universitätzu Luebeck Luebeck, Germany . Thieme Stuttgart · New York .