Histology of the Human Ear I. External ear (Figure ... - Faculty.rmc.edu

III. Inner Ear (Figure 25.1, 25.3, 25.7)
A. Osseus Labyrinth
1. cavity in temporal bone
2. contains membranous labyrinth
3. also contains perilymphatic fluid space between bone and membranous labyrinth which
forms the vestibule and the outer channels of the cochlea (vestibular duct and tympanic
duct)
4. areas between bone and fluid spaces filled with loose FECT
5. fluid spaces are lined with simple squamous epithelium
B. Membranous Labyrinth
1. lined with simple squamous epithelium in most areas
2. lined with simple columnar epithelium with "hair" cells in sensory areas
3. lined with simple cuboidal or columnar epithelium in fluid production/resorption areas
4. epithelium underlain by loose FECT in most areas
C. Sensory Receptor Structures in the Inner Ear (Figure 25.8, 25.9)
1. Common features of receptors
a. Sensory receptors in all cases are "hair" cells.
(1) "Hair" cells are columnar epithelial cells in the wall of the membranous
labyrinth.
(2) "Hair" cells have an apical V-shaped array (viewed from the surface) of
microvilli.
(3) "Hair" cells have either a kinocilium (sensory cilium, found in hair cells in the
maculae and the ampullae) or the basal body of a kinocilium (in the hair cells of
the Organ of Corti in the cochlea) is located at the apex of the "V" shaped array
of microvilli.
b. The processes (microvillae) of the hair cells are embedded in gelatinous accessory
structures which modify the stimuli (gravity, movement, sound) into mechanical
motion of the hair cell processes.
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