Hearing and Balance Disorder Flashcards
approx. 2.5 cm long, lateral third: elastic cartilaginous & dense fibrous framework, medial two-thirds: bone lined with thin skin, ends at the tympanic membrane.
External auditory canal
separates middle from external ear
Typanic membrane (eardeum)
secrete a brown, waxlike substance: cerumen/ear wax
Ceruminous glands
anterior to the external auditory canal; the head of the mandible can be felt by placing a fingertip in the external auditory canal while the patient opens and closes the mouth.
Temporomandibular Joint (TMJ)
composed mainly of cartilage, except for the fat and subcutaneous tissue in the earlobe, collects the sound waves and directs vibrations into the external auditory canal.
Auricle
air-filled cavity, includes the tympanic membrane laterally and the otic capsule medially.
Middle ear
which is approximately 1 mm wide and 35 mm long, connects the middle ear to the nasopharynx.
Esutachian tube
the eustachian tube opens by the action of the ______ when the person performs a Valsalva maneuver, yawns, or swallows.
tensor veli palatini muscle
It drains normal and abnormal secretions of the middle ear and equalizes pressure in the middle ear with that of the atmosphere.
Estachian tube
about 1 cm in diameter, very thin, pearly gray, translucent; protects the middle ear and conducts sound vibrations from the external canal to the ossicles; sound pressure is magnified 22 times.
Tympanic membrane (eardrum)
Assist in the transmission of sound.
Ossicles
3 smallest bones in the ears
malleus (hammer)
incus (anvil)
stapes (stirrup)
Separate the middle from the inner
2 fenestrae (oval, round window)
sits in the oval window, transmits sound to the
inner ear
Footplate of the stapes
The footplate of the stapes is secured by the_____
Fibrous annulus
provides an exit for sound vibrations`
Round window
3 layers of the typanic membrane
Outer layer
Fibrous middle layer
Inner mucosal layer
80% composed of all three layers of the typanic membrane
Pars tensa
20% lacks the middle layer
Pars fllaccida`
True or false: The absence of this fibrous middle layer makes the pars flaccida more vulnerable to pathologic disorders than the pars tensa
TRUE
The cochlea and semicircular canals are housed in the
Bony labyrinth
The cochlea and semicircular canals are housed in the
Bony labyrinth
surrounds and protects the membranous labyrinth
Bony labyrinth
The fluid that baths the membranous labyrinth
Perilymph