Comprehensive Guide to Outer Ear Health and Functions
Explore the structure, functions, common disorders, and malformations of the outer ear. Learn about cerumen, otoscopy, injuries, and hearing loss associated with ear canal issues.
Comprehensive Guide to Outer Ear Health and Functions
E N D
Presentation Transcript
The Outer Ear SPA 4302 Summer 2004
External Auditory Canal • lateral portion-cartilage • medial portion-osseous • lined with epidermal (skin) tissue • hairs grow in lateral part • cerumen (ear wax) secreted in lateral part. • Usually curved.
Outer Ear Functions 1 • Amplification / Filtering -- increases sounds between 1500 and 7000 Hz by 10 to 15 dB -- produced by resonance of Concha -- 5000 Hz E.A.Canal -- 2500 Hz
Outer Ear Functions 2 • Protection -- medial displacement of ear drum -- curvature of canal -- hairs -- cerumen -- skin migration
Outer Ear Functions 3 • Localization -- The ability to identify the location of a sound source
Otoscopy • Viewing outer ear and TM Looking for: • Landmarks, • Evidence of infection • Other Anomalies
Lateral Process (Malleus) = Annulus Malleus Manubrium Umbo Cone of Light
Disorders: • Blockage: with earwax, foreign bodies, pus. • Otitis Externa: swimmer's ear. • Fungal or Bacterial in origin. • More frequent in ears with small canal • openings that cannot dry out as easily. • This is also sometimes a problem for people wearing hearing aids.
Car Accident Victim Who just didn’t “feel right” afterward…
Exostoses: Benign bony growths in the outer ear canal • Contrast with Osteomas
A False Tympanic Membrane • A layer of dead skin cells builds up in persons who use earplugs or some hearing aids frequently
Malformations: congenital, traumatic or surgical. • Microtia: external ear is small, malformed • Atresia: ear canal is closed off. • Post-cancer surgery.
Hearing Loss accompanying these disorders: • Blockage or atresia: • moderate flat conductive hearing losses. • usually medically or surgically treatable. • additional HL if congenital --associated problems w/ cochlea • Surgical or traumatic: • mid to high frequency conductive. • prosthetics available, expensive.