NETTER - Neuroscience Flash Cards

Development of the Ear
1. Tympanic cavity
2. Cranial nerve (CN) VIII
3. Developing semicircular canals
4. Developing cochlear duct
5. Stapes
6. Incus
7. Malleus
8. Cochlear duct
9. Ductus reuniens
10. Utricle
11. Ampulla
12. Semicircular canals (12a—anterior; 12b—posterior; 12c—lateral)
Comment: CN VIII derives from neural crest cells. The outer ear
(auricle, external auditory meatus) develops from the first pharyngeal
grove; the middle ear (the ossicles) develops from the first
pharyngeal pouch; and the inner ear (bony labyrinth, membranous
labyrinth, the cochlea, the semicircular canals) develops from the
otic placode. Hair cells associated with the utricle (otolith organ)
and semicircular canals (ampullae) respond to linear acceleration
and angular acceleration, respectively. Hair cells in the organ of
Corti on the basilar membrane respond to differential movement of
the tectorial membrane and basilar membrane due to fluid waves
generated through the scala vestibule and tympani, transmitted to
the cochlear duct. These hair cells provide stimulation of auditory
primary axons that transmit sound.
Overview of the Nervous System See book 8.21