d_05.1. Ear (spiral cochlear canal)
(hematoxylin-eosin)
1. Low magnification - study the structure of the cochlear canal:
- vestibular/ Reissner's membrane and basilar membrane separate the cochlear duct into the scala vestibuli , scala tympani and the cochlear duct (scala media), lies between the larger vestibular and tympanic scalae;
- the outer wall of the cochlear duct of the membranous labyrinth is made up of stria vascularis, fusing with the bone wall by means of the spiral ligament;
- the cochlear duct is separated from the scala vestibuli, lying over it, by the vestibular membrane; and from the scala tympani, lying under it, by the basilar membrane;
- within the spiral crest ridge there’s a spiral ganglion (sensory neurons);
- on the surface of the basilar membrane there’s spiral (or Corti) organ.
- Draw and sign: 1 - scala vestibuli, 2 - scala tympani, 3 - cochlear duct (scala media) of the membranous labyrinth, 4 - vestibular/ Reissner's membrane, 5 - basilar membrane, 6 - spiral crest, 8 - stria vascularis, 9 - spiral ligament, 10 - spiral (or Corti) organ, 11 - spiral ganglion.
2. Study the components and cellular structure of the spiral organ in high magnification
- Draw and sign: 1 - inner phalangeal cells, 2 - outer phalangeal cells, 3 - inner hair cells, 4 - outer hair cells, 5 - inner tunnel, 6 - outer pillar cells, 7 - inner pillar cells, 8 - tectorial membrane.
3. Define and write significant features of the slide.