The Vestibulocochlear Organ

Functions and formations

external ear

middle ear

internal ear

collecting and transmitting sound waves

receiving the stimulation of both sound waves and changes of the position of the head

1. The external ear

① auricle

② external acoustic meatus

③ tympanic membrane

cartilaginous part

bony part

flaccid part tense part

2. The middle ear

tympanic cavity

auditory tube

mastoid cells

① tympanic cavity

sup. wall: tegmental w.inf. wall : jugular w.

ant. wall: carotid w.post. wall: mastoid w.

lat. wall: membranous w.med. wall: labyrinthine w.

promontory fenestra vestibuli / fenestra cochlea prominence of facial canal

prominence of facial canal

fenestra vestibuli

fenestra cochlea

tympanic promontory

auditory ossicles

① tympanic cavity

the malleus

the incus

the stapes

② auditory tube

③ mastoid cells

3. The internal ear bony labyrinth

membranous labyrinth

① The bony labyrinth

cochlea

vestibule

bony semicircular canals

cochlea

vestibule

bony semicircular canals

② The membranous labyrinth

cochlear ductspiral organ

utricle & saccule: macula utriculi and macula sacculi

membranous semicircular ducts: ampullary crest

osseous spiral lamina

modiolusscala vestibuli

scala tympani

helicotrema

cochlear duct

spiral organ

Bony labyrinth

cochlea vestibule Semicircular canals(osseous ampullae)

Membranous labyrinth

Cochlea duct Utricle and saccule Semicircular canals(membranous ampullae)

receptor Spiral organ Macula utriculi Macula sacculi

Ampullary crest

funtion Hearing sensation Balance of body Static

Blance of bodyKinetic

summary

_____ The conduction of the sound

The first passway (aerial conduction)

The sound waves

external acoustic meatus

tympanic membrane

chain of auditory ossicles

fenestra vestibuli

the perilymph within the scala vestibuli

the endolymph within the cochlear duct

the spiral organ

nerve impulse

helicotremathe perilymph within the scala tympani

The second passway (aerial conduction)

nerve impulse

The sound wave

external acoustic meatus

air in the tympanic cavity

membrane on the fenestra cochlea

the perilymph within the scala tympani

the endolymph within the cochlear duct

the spiral organ

The third passeway (bony conduction)

the spiral organ

The sound wave

the bony labyrinth

the perilymph within scala vestibuli and scala tympani

the endolymph within the cochlear duct

skull

nerve impulse