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Vestibular System
VESTIBULAR SYSTEM
I. ANATOMY
A. Peripheral Vestibular System
1. External ear
Auricle thin elastic cartilage covered
with skin that collects vibrations
External auditory meatus curve tube
from the auricle to the tympanic
membrane (ear drum); contains
yellowish brown wax that prevents
entry of foreign objects
2. Middle ear/ Tympanic cavity narrow,
oblique, slit-like cavity parallel to the
eardrums
Auditory ossicles transmits signals
from tympanic membrane to oval
window
o Malleus/Hammer
- Largest
- Long process: attached to
eardrum
- Head: attached to incus
o Incus/Anvil
- Body: attached to malleus
- Long process: attached to
stapes
o Stapes/Stirrup
- Head: attached to incus
- Base: attached to oval
window
Movement of Auditory Ossicles
- Medial: tympanic membrane and long
process of malleus
- Lateral: head of malleus and body of incus
- Medial: long process of incus and head of
stapes
3. Internal ear
Bony labyrinth
Membranous labyrinth
- Contains
perilymph
- Contains endolymph
1. Semicircular
canal
- Sup/Ant SCC
- Inf/Post SCC
- Lat/Horizontal
SCC
1. Semicircular ducts