Auditory system Flashcards
what is the pinna also known as?
auricula
What is the external auditory meatus?
osseous part of the external ear
What is the external auditory canal?
consists of osseous and cartilage of the external ear
what is the function of the external ear?
collect air, conduct sound, waves and allow access to the tympanic membrane
What is the middle ear also known as?
tympanic cavity
What are the ossicles of the middle ear?
malleus
Incus
Stapes
What are the openings of the osseous labrinth of the inner ear?
oval window
round window
what is another name for the oval window?
fenestra vestibuli
what is another name for the round window?
fenestra cochlea
What covers the oval window?
foot plate of the stapes
what covers the round window?
secondary tympanic membrane
Where are vibrations of the tympanic membrane transferred?
transferred through the ossicular chain to the oval window and leads a pressure change in the inner ear
what are the muscles of the ear?
tensor tympani muscle
stapedius
what innervates the tensor tympani muscle?
V nerve
What innervates the stapedius muscle?
VII nerve
What is the function of the muscles of the ear?
dampen/ attenuate movements of ossicles and tympanic membrane in response to high intensity sounds
what are the two portions that make up the inner ear?
osseous and membranous labyrinths
What is the osseous labyrinth?
consists of a system of interconnecting spaces located in the petrous part of the temporal bone
What fills the osseous labyrinth?
perilymph
what are the parts of the osseous labyrinth?
semicircular canal (posterior)
Vestibule (middle)
cochlea or cochlear canal (anterior)
What is the central bony axis of the cochlea called?
modiolus
How many turns does the cochlea do around the modiolus?
2.75
What is the membranous labyrinth?
Consists of a series of interconnecting membrane tubes that are suspended within the spaces of the osseous labyrinth
What is the lumen of the membranous labyrinth filled with?
endolymph
what are the parts of the membranous labyrinth/
semicircular ducts
utricle
saccule
cochlear duct
Where are the utricle and saccule found?
within vestibule of osseous labryinth
What 3 parts is the cochlear canal divided into?
scala media
scala vestibuli
scala tympani
What is the scala media?
cochlear duct which forms the middle space
what is scala vestibuli?
space superior to the scala media filled with perilymph
What is the scsala tympani?
interior to the scala media filled with perilymph
what is the small opening where at the apex of the cochlea where the scala tympani and scala vestibuli communicate known as?
helicotrema
what window is the scala tympani continuous with?
Round window
Do all three scala spiral up the cochlear canal?
Yes, all three scala spiral up the cochlear canal
What is the cochlear duct?
membranous duct suspended in the middle of the cochlear canal
What are the three wall borders of the cochlear duct?
vestibular membrane
stria vascularis
basilar membrane