Term
| The ear is a complex structure containing _____ for _____ and _____. |
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Definition
| sensory receptors, hearing, equilibrium |
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Term
| three major areas of the ear |
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Definition
| external (or outer) ear, middle ear, and internal ear |
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Term
| general function of the external and middle ear |
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Definition
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Term
| general functions of the internal ear |
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Definition
| both equilibrium and hearing reception |
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Term
| two primary structures of the external ear |
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Definition
| auricle (or pinna) and external acoustic meatus (or external auditory canal) |
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Term
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Definition
| a short, narrow chamber carved into the temporal bone with skin-lined wall lined with wax-secreting glands called ceruminous glands |
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Term
| What separates the external and middle ear, and what is its function? |
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Definition
| the tympanic membrane (or eardrum); vibrates at exactly the same frequency of the sound waves |
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Term
| The middle ear is essentially a small chamber called the ____. |
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Definition
| tympanic cavity, found within the temporal bone |
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Term
| What is inside of the tympanic cavity? |
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Definition
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Term
| What are the auditory ossicles? |
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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) |
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Term
| What connects the vibratory motion of the eardrum to the fluids of the inner ear? |
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Definition
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Term
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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 |
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Term
| Why is equal pressure inside and outside of the ear important? |
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Definition
| without this, the eardrum cannot vibrate properly |
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Term
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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 |
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Term
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Definition
| a system of bony and twisting chambers making up the internal ear, filled with perilymph |
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Term
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Definition
| a system that is inside of perilymph of the bony labyrinth and mostly follows its contours; filled with endolymph |
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Term
| three subdivisions of the bony labyrinth |
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Definition
| cochlea, vestibule, and semicircular canals |
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Term
| general function of the vestibule and semicircular canals |
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Definition
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Term
| The cochlea is _____ and has _____. |
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Definition
snail-like
sensory receptors for hearing |
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Term
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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) |
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Term
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Definition
| aka vestibular duct; upper chamber of the cochlear cavity that contains perilymph |
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Term
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Definition
| aka cochlear duct; middle chamber of cochlear duct containing endolymph |
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Term
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Definition
| aka tympanic duct; lower chamber of cochlear duct containing perilymph |
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Term
| What binds the scala tympani? |
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Definition
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Term
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Definition
| part of the cochlea; contains the receptors for hearing |
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Term
| What are the receptors for hearing? |
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Definition
| sensory hair cells and nerve endings of the cochlear nerve |
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Term
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Definition
| the floor of the cochlear duct that the hair cells rest on |
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Term
| hair cells are also called |
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Definition
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Term
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Definition
| a gelatinous membrane that overlies the hair cells, and they project into it |
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Term
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Definition
| roof of the cochlear duct |
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Term
| two parts of the vestibule |
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Definition
| saclike utricle and saccule |
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Term
| The semicircular canals contain _____, that are for what? |
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Definition
| membranous semicircular ducts- anterior (nodding head), posterior (moving head from shoulder to shoulder), and lateral (shaking head) |
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Term
mechanism of hearing
step 1. |
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Definition
| sound waves pass through external acoustic meatus and through the middle ear into the internal ear, where vibrations reach the spiral organ |
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Term
mechanism of hearing
step 2. |
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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 |
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Term
mechanism of hearing
step 3. |
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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 |
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Term
mechanism of hearing
step 4. |
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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 |
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Term
mechanism of hearing
step 5. |
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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 |
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Term
| Where do the different-frequency waves peak? |
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Definition
high-close to the oval window
low-farther up the basilar membrane near the cochlear apex |
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