SPECIAL SENSES: HEARING & SPECIAL SENSES: HEARING & EQUILIBRIUMEQUILIBRIUM

MARTINI, FUNDAMENTALS OF ANATOMY & MARTINI, FUNDAMENTALS OF ANATOMY & PHYSIOLOGY, 9PHYSIOLOGY, 9THTH EDITION, CHAPTER # 17 EDITION, CHAPTER # 17

ExerciseExercise # # 2222

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NOTE:NOTE:

THIS IS A THIS IS A STUDY GUIDESTUDY GUIDE, , NOTNOT AN AN ALLALL INCLUSIVE REVIEW. INCLUSIVE REVIEW.

THERE THERE MIGHT BEMIGHT BE THINGS THINGS NOT COVEREDNOT COVERED BY THIS BY THIS STUDY GUIDE THAT STUDY GUIDE THAT MIGHT BEMIGHT BE ASKEDASKED IN YOUR IN YOUR PRACTICUMSPRACTICUMS / /

QUIZZESQUIZZES..

STUDENTSSTUDENTS ARE ARE RESPONSIBLERESPONSIBLE FOR FOR READINGREADING THEIR THEIR TEXBOOKTEXBOOK (S) AND FOR ALL THE MATERIAL (S) AND FOR ALL THE MATERIAL COVERED DURING THE COVERED DURING THE LABORATORY PERIODLABORATORY PERIOD, , AS PER THE COURSE AS PER THE COURSE SYLLABUSSYLLABUS

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OBJECTIVESOBJECTIVES

Identifying the structures of the ear and Identifying the structures of the ear and describe their functions.describe their functions.

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EXTERNAL EAREXTERNAL EAR

MIDDLE EARMIDDLE EAR

INNER, OR INTERNAL EARINNER, OR INTERNAL EAR

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EXTERNAL EAREXTERNAL EAR

Pinna or auriclePinna or auricle- to capture the sound waves- to capture the sound waves External auditory canalExternal auditory canal-to focus & direct the sound waves-to focus & direct the sound waves Ceruminous glandsCeruminous glands (lining the external auditory canal) (lining the external auditory canal) f- to produce waxy materialf- to produce waxy material To avoid foreign matters to go inside To avoid foreign matters to go inside

Tympanic membraneTympanic membrane- to transmit the sound waves- to transmit the sound waves

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MIDDLE EARMIDDLE EAR

Ossicles Ossicles (3 little bones)- (3 little bones)- malleus, incus & stapesmalleus, incus & stapes F- to transmit the sound wavesF- to transmit the sound waves Pharyngotympanic or auditory or eustachian tubePharyngotympanic or auditory or eustachian tube

F- to equalize the pressure inside & outside the F- to equalize the pressure inside & outside the tympanic membranetympanic membrane

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INNER OR INTERNAL EARINNER OR INTERNAL EAR

The bony labyrinthThe bony labyrinth -it has -it has 3 parts3 parts- - vestibule, vestibule, semicircular canal & cochleasemicircular canal & cochlea

It surrounds the membranousIt surrounds the membranous labyrinthlabyrinth It contains the It contains the perilymphperilymph PerilymphPerilymph (pink in model)-to transmit sound waves (pink in model)-to transmit sound waves Membranous labyrinthMembranous labyrinth ( (grey in modelgrey in model)- it Contains the )- it Contains the endolymphendolymph EndolymphEndolymph- to transmit sound waves- to transmit sound waves

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VestibuleVestibule- balance & equilibrium- balance & equilibrium It contains the It contains the utricle & saculeutricle & sacule Utricle & saculeUtricle & sacule- contain the- contain the maculamacula F- sensations of gravity & linear accelerationF- sensations of gravity & linear acceleration

Semicircular canalsSemicircular canals- sense of dynamic balance- sense of dynamic balance AmpullaAmpulla- swollen area at the end of the- swollen area at the end of the Semicircular canal that contains the Semicircular canal that contains the CristaCrista CristaCrista- contains sensory receptors for - contains sensory receptors for dynamic balancedynamic balance

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INNER EARINNER EAR: : COCHLEACOCHLEA

It contains It contains receptors for hearingreceptors for hearing It has 3 ducts or chambersIt has 3 ducts or chambers vestibular ductvestibular duct ( (scala vestibuliscala vestibuli)-pink in model)-pink in model UpperUpper duct that contain duct that contain perilymphperilymph Cochlear ductCochlear duct ( (scala mediascala media)-blue in model)-blue in model MiddleMiddle duct that contains duct that contains endolymphendolymph Tympanic ductTympanic duct ( (scala tympaniscala tympani)- green in model)- green in model LowerLower duct that contains duct that contains perilymphperilymph Oval windowOval window (at the base of the stapes)- (at the base of the stapes)- F- to transmit sound to the inner earF- to transmit sound to the inner ear Round windowRound window- it separates the perilymph of the - it separates the perilymph of the cochlear duct from air spaces of the middle ecochlear duct from air spaces of the middle e

F- it releases excess pressureF- it releases excess pressure

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INNER EARINNER EAR: : THE ORGAN OF CORTITHE ORGAN OF CORTI

3 membranes around the organ of corti3 membranes around the organ of corti Vestibular membraneVestibular membrane (upper one)- to separate (upper one)- to separate the cochlear duct from scala vestibulithe cochlear duct from scala vestibuli Tectorial membraneTectorial membrane (in the middle of the (in the middle of the cochlear duct)- it stimulates hair cellscochlear duct)- it stimulates hair cells Basilar membraneBasilar membrane (bottom one)- to transmit (bottom one)- to transmit the vibration to the hair cellsthe vibration to the hair cells

Organ of cortiOrgan of corti- it contains the - it contains the hair cellshair cells that that produce the hearing signalproduce the hearing signal

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REMEMBER!REMEMBER!

GO TO THE TUTORING ROMMGO TO THE TUTORING ROMMAND PRACTICE WITH MODELS.AND PRACTICE WITH MODELS.

ROOM 3326.ROOM 3326.