Class 11/12 - Hearing & Equilibrium Flashcards
Auditory receptors transduce small amplitude vibrations ____x faster than photoreceptors respond to light
1000
The external auditory canal is found within the ____ bone
temporal
What separates the external and middle ear?
tympanic membrane (ear drum)
What order are the ossicles arranged in?
malleus - incus - stapes
What two muscles attach to the ossicles? What is their function and innervation?
tensor tympani (CN V) tenses eardrum to prevent damage from loud noises stapedius (CN VII) prevents damage to oval window
The stapedius muscle cannot protect from…
brief, very loud noises (like a gunshot)
Stapedius mm paralysis results in…
hyperacusia
The bony labyrinth contains the ____ within the _____
membranous labyrinth within the perilymh
The bony labyrinth is composed of the ___, ___, and ___.
cochlea, vestibule and semicircular canals
The round window at one end of the cochlea is sealed by the…
secondary tympanic membrane
The plate of stapes fits into the ____
oval window
What are the two passages within the cochlea? What are they filled with?
scala vestibuli
scala tympani
perilymph
In between the scala vestibuli and scala tympani is the ____, containing ___ and _____.
cochlear duct, containing the endolymph and spiral organ/organ of Corti
The vestibule is a bony space connecting the cochlea and semicircular canals. What two sacs of the membranous labyrinth are found within it?
utricle and saccule
The utricle and saccule are used for…
static equilibrium
The semicircular canals contain receptors for…
dynamic equilibrium
The semicircular canals have enlargements called ___ which open into the vestibule.
ampullae
The membranous labyrinth includes the ___, __, ___, and _____.
cochlear duct, utricle, saccule, and semiricular ducts
The range of sound most accurately heard by humans is between:
500-5000Hz
What is the function of the round window?
dissipates the vibrational wave
The first order neurons in the cochlear ganglion form the cochlear portion of the VII cranial nerve, which will enter the ____ and synapse with second order neurons in the _______ nuclei
medulla oblongata
cochlear nuclei
In the auditory pathway, some axons decussate in the medulla and ascend as the lateral lemniscus to terminate in the ____ of the midbrain. Others will end in the _____ in the pons on each side, to then head to the ______.
inferior colliculi
superior olivary nucleus
inferior colliculi
The right and left primary auditory areas in the temporal lobe will receive impulses from _____
BOTH EARS EACH
From each inferior colliculis in the auditory pathway, impulses are conveyed to the ____ of the thalamus, which will then project to the primary auditory area in the temporal lobe.
medial gerniculate body
The vestibular apparatus consists of…
the saccule, utricle, and semicircular ducts
What are the otholiths?
dense carbonate crystals extending over the surface of the otholitic membrane within the saccule and utricle
The macula of the saccule and utricle are ___ to each other
perpendicular
The maculae of the inner ear provide information on:
position of the head in space
linear acceleration and deceleration
The maculae in the inner ear contain two kinds of cells:
hair cells (sensory receptors) containing hair bundles
+
supporting (columnar) cells that secrete the otholitic membrane that rests on the hair cells
Receptor potentials in the maculae are triggered when…
the otholiths are pulled by gravity in the direction of the tilting head, bending the hair bundles
Hair cells in the maculae synapse with __ order neurons in the ____ ganglion
1st order, vestibular ganglion
ADD IN AUDITORY PATHWAY
ADD IN VESTIBULAR PATHWAY
