Speech Hearing Disorders 1 Flashcards
Anotia
absence of an auricle
Microtia
abnormally small or misshapen auricle, has a grading system
Preauricular Pits and Tags
pits: small hole lying anterior to the auricle
tags: appendage lying anterior to the auricle
Seroma
a collection of serous fluid in the subperichondrial layer
Hematoma
traumatic disruption of a perichondrial blood vessel due to severe trauma
Allergic Dermatitis
reactive inflammation of the auricle, NO PAIN
Cellulitis of the Auricle
a bacterial infection that begins with abrasion/laceration which becomes a bacterial infection of the epidermis, PAIN
Basal Cell Carcinoma
very common skin cancer, symptoms: otorrhea, facial paralysis, can cause difficulty hearing
The EAC
function: directs sounds to the TM, and serves as an acoustic resonator, by 1-4k Hz range
Atresia
absence of the opening of the EAC, very accompanied by microtia, is almost ALWAYS congenital, but it can be acquired. Causes significant hearing loss as great as 60 Db. Has severity grades.
Acute Diffuse Generalized Otitis Externa
also called “swimmer’s ear”, caused by water trapped in the ear canal and causes the EAC ph balance to go from acidic to basic.
Allergic Otitis Externa
allergic reaction within the EAC and causes infection, symptoms: itching, swelling, rash
middle ear
Otomycosis
infection of the EAC caused by fungi or yeast, debris in the EAC may be white, black, or grey
Cerumen Impaction
causes hearing loss, and can be removed by alligator forceps, suction, or water flush
Exostosis
also called “surfer’s ear”, BILATERAL protrusions in the bony wall of the EAC due to consistent cold saltwater exposure
Osteoma
bony tumor that occurs among middle-aged adults, solitary and UNILATERAL, rare
outer ear
Tympanosclerosis
white calcified plaques of connective tissue occurring at and around the circumference of the TM and/or the head of the malleus, causes the TM to be more stiff
middle ear
Myringosclerosis
when white calcified plaques form only on the TM, often confused with tympanosclerosis, usually happens from a previous PE tube
middle ear
TM Perforation
a common complication of middle ear infection, can also occur due to trauma, may or may not cause a CHL
middle ear
Eustachian Tube
purpose is to equalize pressure within the middle ear cavity and that of the env., to clear/drain secretions of the middle ear
Eustachian Tube Dysfunction
a condition in which the ET does not function properly, preventing the equalization of air pressure bn the middle ear space and the env. most COMMON disorder
symptoms: aural fullness, pain or discomfort, difficulty popping ears, retracted TM
Otitis Media with Effusion
presence of fluid in the middle ear without signs or symptoms of acute ear infection. NO PAIN
primary cause- the ME is a mucosa-lined space and the ET allows the ME to be an air-filled space, when pressure cannot be equalized, negative pressure builds in the ME space and creates a relative “vacuum”, overtime this vacuum effect pulls from the mucosal lining of the ME, filling the space with fluid, and since the ET is obstructed this fluid cannot drain out of the tympanum
Parents may notice- ear rubbing, inattention, communication difficulties, and disturbed sleep
Treatment: if not resolved by 3rd month then PE tubes will be placed
middle ear
Acute Otitis Media
infectious, inflammatory condition of the ME usually caused by bacterial infection of fluid behind the TM, PAIN
Cholesteatoma
an abnormal growth of skin that becomes trapped in the middle ear cavity, will occur at pars flaccida (superior) because it has two layers instead of three
MAY cause up to 50 dB of HL
Paragangliomas
benign, slow growing, and highly vascularized neoplasms of the body, SIGN- pulsatile tinnitus
middle ear
Otosclerosis
spongy bone growth over the stapedial footplate, partially fixating the footplate in the oval window, usually occurs bilaterally
SIGN- carhart notch(a decline in bone conduction thresholds at 2000 Hz)
middle ear
Presbycusis
decrease in auditory function that occurs with aging, #1 cause of acquired SNHL!! SIGN- sloping bilateral SNHL that gradually progresses over time
Noise-Induced Hearing Loss
exposure to excessive sound results in a change in the threshold of hearing sensitivity, SIGN- noiseeee notchhhh
Degree of NIHL depends on:
1) duration and intensity
2) frequency of the noise
3) exposure frequency
Ototoxicity
hearing loss that results from the ingestion of certain drugs that are administered for medical purposes, such as in the treatment of infections and cancer; causes a high frequency SNHL past 8000 Hz
Transverse
plane separating top and botton
Coronal
plane separating front and back
Sagittal
plane separating structure into right and left (medial, lateral, dextral(right), sinistral(left))
EAC
outer 2/3 is composed of skin-covered cartilage and inner 1/3 is skin-covered bone, not straight by 2 curves “S”, the canal has slight downward turn at each end
TM
3 layers and 2 sections (pars flaccida and pars tensa)
Tensor Tympani
attaches to the malleus
Stapedius Tympani
attaches to the stapes
Osseous Labyrinth
channel in the temporal bone which contains the membranous labyrinth, formed by 3 main structures: the vestibule, semicircular canals, and the cochlea
Membranous Labyrinth
composed of soft-tissued fluid-filled channels within the osseous labyrinth that contain the end-organ structures of hearing and balance
Outer Hair Cells
cilia are embedded into the tectorial membrane, which covers the organ of corti, 3 rows
Inner Hair Cells
cilia are close to, but not in contact with tectorial membrane, 1 row
Auricle
mainly serves to collect and funnel sounds, serves for sound localization in the vertical plane, provides protection, serves as an resonator to up to 5000 Hz
EAC
directs sound to TM, the resonator of 3000-4000 Hz, protect the TM, protects from infection
Impedance Matching Transformer
impedance= the resistance to the flow of energy
cochlea is filled with fluid and the ossicles serve to optimize the flow of energy, the ME transformer action allows us to maintain the sound energy even though it is passing through substances with different amounts of impedance, without this transformer action, about 30 dB would be lost as it travels to the cochlea.
Impedance Matching Methods
1) Size difference bn the TM and the stapes footplate- pressure applied on the large end results in substantially greater pressure at the smaller end
2) Lever action of the ossicles- the malleus and incus pivot around their point of connection, the incudomalleoular joint, which contributes to an inc in vibrational amplitude at the stapes
3) The buckling action of the TM- a buckling action when the TM vibrates causes the malleus to move with 2X the amt of force compared with more simple vibration of the TM
Muscle Tendons of the ME
the tendons pull the malleus and stapes in two different directions which stiffens the ossicular chain, this reduces intense sound energy traveling to the inner ear, this ultimately protects the hair cells of the inner ear from high intensity sound
Cochlear Wave Mechanics
- the stapes moves in and out of the oval window which creates fluid movement in the cochlea,
-this sets the BM into a wavelike motion (traveling wave)
-the TW moves down the course of the BM, growing in magnitude until it reaches its pt of mx displacement,
-when the TW reaches its pt of max displacement, the IHCs are stimulated,
-this results in the release of the neurotransmitter, glutamate,
-which results in the firing of the auditory nerve fiber associated with the IHC
Role of Outer Hair Celss
electromotility= the unique ability of the OHCs to rapidly contract and expand in response to a sound stimulus
Cochlear Amplifier- increases sensitivity to low-intensity sounds by enhancing the vibratory stimulus delivered to the inner hair cells
Increasing Frequency Discrimination- contraction and expansion only occur in a restricted area of the BM, so the peak region of deflection is sharper in this area and therefore frequency tuning is enhanced
