NETTER - Neuroscience Flash Cards

Bony and Membranous Labyrinths
1. Anterior semicircular canal and duct
2. Posterior semicircular canal and duct
3. Lateral semicircular canal and duct
4. Stapes in oval window
5. Incus
6. Malleus
7. External acoustic meatus
8. Tympanic cavity
9. Tympanic membrane
10. Round window
11. Pharyngotympanic (auditory) tube
12. Scala tympani
13. Cochlear duct
14. Scala vestibuli
15. Helicotrema of cochlea
16. Saccule
17. Utricle
Comment: The semicircular canals (ducts) contain the ampullae
with hair cells that respond to angular acceleration. The utricle
contains the otolith organ in the macula that responds to linear
acceleration and detects gravitation. The saccule responds best to
vibratory stimuli. The cochlea contains the hair cells that respond
to fluid movements within the scala vestibule and tympani; these
affect fluid movement in the cochlear duct and are brought about by
mechanical leveraging of the ossicles against the oval window. The
activity of the utricle can sometimes become distorted when debris
moves away from the hairs and induces activation of the hair cells in
the ampulla of the posterior semicircular canal. This produces vertigo
and nystagmus that are associated with a specific position of the
head, known as benign postural or positional vertigo.
Systemic Neuroscience See book 14.13