Ent Practical - Ear Anatomy Flashcards
What two structures contain perilymph?
Membranous labyrinth and bony labyrinth
What structure contains endolymph
Membranous labyrinth
What two structures are contained with the labyrinths?
Semicircular canals and cochlea
What two structures make up the vestibular apparatus
Vestibule and semicircular canals
Where is the vestibule found
In central portion of bony labyrinth, posterior to the cochlea and anterior to the semicircular canals
What is suspended in the perilymph of the vestibule
2 membranous sacs: the saccule and the utricle
What is the saccule continuous with
The membranous labyrinth; extends anteriorly as the cochlear duct
What is the utricle continuous with
Semicircular ducts that extend posteriorly into semicircular canals
What are the maculae
Equilibrium receptor regions of sacs; transmit changes in head position
What are the three semicircular canals
Anterior, posterior, and lateral
What is contained in each semicircular canal?
Semicircular duct that communicates with utricle anteriorly
What is the enlarged swelling at the end of each duct
Ampulla
What is the equilibrium receptor region that responds to rotational movements of the head
Crista ampullaris
What is the position of the head sensed while head and body remain stable
Static equilibrium
What responds to linear acceleration
Macula of utricle and saccule
During static equilibrium, what responds to tilting of the head to the side?
Utricle; macula is horizontal
During static equilibrium, what responds to vertical movement
Saccule; macula is vertical
What is it called when the head and body move or rotate, motion is detected, and aids in balance
Dynamic equilibrium
What controls dynamic equilibrium
Semicircular canals
What does the cochlea coil around
Bony modiolus
What structure is along the modiolus
Osseous spiral lamina
What goes through the center of the cochlea and what is it filled with
Cochlear duct filled with endolymph
What is the cavity of the cochlea divided into and what is it filled with
Scala; perilymph
What is the receptor of sound and what structure on it
The hairs on the organ of corti
What supports the organ of corti
Basilar membrane
What is above the hair cells
Tectoral membrane
What is sound
A series of pressure disturbances of varying frequencies
Movement of the stapes transmits vibration to the ______ in the ______
Perilymph; scala vestibuli
Vibrations pass through and enter _____ of the _____
Endolymph; cochlear duct
What is the normal range of decibels for humans without extreme pain
Up to 120db
