Membranous labyrinth (labels) - histology illustration

Membranous labyrinth from the postero-medial aspect. 1. Lateral semicircular canal; 1’, its ampulla; 2. Posterior canal; 2’, its ampulla. 3. Superior canal; 3’, its ampulla. 4. Conjoined limb of superior and posterior canals (sinus utriculi superior). 5. Utricle. 5’. Recessus utriculi. 5". Sinus utriculi posterior. 6. Ductus endolymphaticus. 7. Canalis utriculosaccularis. 8. Nerve to ampulla of superior canal. 9. Nerve to ampulla of lateral canal. 10. Nerve to recessus utriculi (in Fig. 925, the three branches appear conjoined). 10’.Ending of nerve in recessus utriculi. 11. Facial nerve. 12. Lagena cochleæ. 13. Nerve of cochlea within spiral lamina. 14. Basilar membrane. 15. Nerve fibers to macula of saccule. 16. Nerve to ampulla of posterior canal. 17. Saccule. 18. Secondary membrane of tympanum. 19. Canalis reuniens. 20. Vestibular end of ductus cochlearis. 23. Section of the facial and acoustic nerves within internal acoustic meatus (the separation between them is not apparent in the section). (G. Retzius.)

Histology illustration courtesy of Gray's Anatomy.