Shared Flashcard Set

Details

Anatomy of the Ear; Hearing
UCCS Bio 2010 Lykins- Lab Practical 4, Ex. 25
38
Anatomy
Undergraduate 1
12/08/2013

Additional Anatomy Flashcards

 


 

Cards

Term
The ear is a complex structure containing _____ for _____ and _____.
Definition
sensory receptors, hearing, equilibrium
Term
three major areas of the ear
Definition
external (or outer) ear, middle ear, and internal ear
Term
general function of the external and middle ear
Definition
hearing only
Term
general functions of the internal ear
Definition
both equilibrium and hearing reception
Term
two primary structures of the external ear
Definition
auricle (or pinna) and external acoustic meatus (or external auditory canal)
Term
external acoustic meatus
Definition
a short, narrow chamber carved into the temporal bone with skin-lined wall lined with wax-secreting glands called ceruminous glands
Term
What separates the external and middle ear, and what is its function?
Definition
the tympanic membrane (or eardrum); vibrates at exactly the same frequency of the sound waves
Term
The middle ear is essentially a small chamber called the ____.
Definition
tympanic cavity, found within the temporal bone
Term
What is inside of the tympanic cavity?
Definition
the auditory ossicles
Term
What are the auditory ossicles?
Definition
three small bones which articulate to form a lever system that amplifies and transmits the vibratory motion of the eardrum to the fluids of the inner ear - malleus (hammer), incus (anvil), and the stapes (stirrup)
Term
What connects the vibratory motion of the eardrum to the fluids of the inner ear?
Definition
the oval window
Term
pharyngotympanic tube
Definition
aka auditory tube; connects the middle ear chamber with the nasopharynx; usually closed but temporarily opens when swallowing or yawning to equalize the middle ear and external air pressure
Term
Why is equal pressure inside and outside of the ear important?
Definition
without this, the eardrum cannot vibrate properly
Term
otitis media
Definition
inflammation of the middle ear due to the mucosal membranes of the middle ear cavity and the nasopharynx being continuous through the pharyngotympanic tube
Term
bony labyrinth
Definition
a system of bony and twisting chambers making up the internal ear, filled with perilymph
Term
membranous labyrinth
Definition
a system that is inside of perilymph of the bony labyrinth and mostly follows its contours; filled with endolymph
Term
three subdivisions of the bony labyrinth
Definition
cochlea, vestibule, and semicircular canals
Term
general function of the vestibule and semicircular canals
Definition
equilibrium
Term
The cochlea is _____ and has _____.
Definition

snail-like

sensory receptors for hearing

Term
cochlear duct
Definition
a soft, worm-like tube in the cochlea that winds through its full 2 and 3/4 turns and separates the perilymph-containing cochlear cavity into upper and lower chambers (scala vestibuli and scala tympani)
Term
scala vestibuli
Definition
aka vestibular duct; upper chamber of the cochlear cavity that contains perilymph
Term
scala media
Definition
aka cochlear duct; middle chamber of cochlear duct containing endolymph
Term
scala tympani
Definition
aka tympanic duct; lower chamber of cochlear duct containing perilymph
Term
What binds the scala tympani?
Definition
the round window
Term
spiral organ
Definition
part of the cochlea; contains the receptors for hearing
Term
What are the receptors for hearing?
Definition
sensory hair cells and nerve endings of the cochlear nerve
Term
basilar membrane
Definition
the floor of the cochlear duct that the hair cells rest on
Term
hair cells are also called
Definition
stereocilia
Term
tectorial membrane
Definition
a gelatinous membrane that overlies the hair cells, and they project into it
Term
vestibular membrane
Definition
roof of the cochlear duct
Term
two parts of the vestibule
Definition
saclike utricle and saccule
Term
The semicircular canals contain _____, that are for what?
Definition
membranous semicircular ducts- anterior (nodding head), posterior (moving head from shoulder to shoulder), and lateral (shaking head)
Term
mechanism of hearing
step 1.
Definition
sound waves pass through external acoustic meatus and through the middle ear into the internal ear, where vibrations reach the spiral organ
Term
mechanism of hearing
step 2.
Definition
vibration of the stirrup at the oval window leads to traveling pressure waves in the perilymph, which leads to maximal displacements of the basilar membrane where the waves peak and stimulate the hair cells
Term
mechanism of hearing
step 3.
Definition
the vestibular membrane is compressed b/c the area where the waves peak is high pressure, and the endolymph and basilar membrane of the cochlear duct are in turn compressed
Term
mechanism of hearing
step 4.
Definition
the pressure in the perilymph in the scala tympani causes the membrane of the round window to bulge outward into the middle ear chamber, acting as a relief valve for the compressional wave
Term
mechanism of hearing
step 5.
Definition
sound reception by the spiral organ-hair cells are stimulated and depolarize and begin the chain of nervous impulses that travel along the cochlear nerve to the auditory centers of the temporal lobe cortex
Term
Where do the different-frequency waves peak?
Definition
high-close to the oval window
low-farther up the basilar membrane near the cochlear apex
Supporting users have an ad free experience!