2 primary functions of the ear
Hearing
-Static and dynamic equilibrium
Outer ear components
Pinna and Ear Canal
Middle Ear
-Tympanic membrane: Subject to noise trauma
-Ossicles: 3 tiny bones with joints between them/Transmit vibrations from tympanic membrane
-Eustachian tube: Equalize the air pressure in the middle ear with that of the outside ear
Two muscles in the middle ear that help dampen sounds when things are really loud
- Tensor Tympani: Trigeminal; Teeth
- Stapedius: Seven (CN 7); Singing sounds
Which cranial nerve carries sound and body position & motoin from the inner ear to brain
Cranial nerve 8 (vestibulocochlear)
Inner Ear
-Cochlea
-Utricle and Saccule
-Semicircular canals
Cochlea
-Snail-shaped with tiny hairs inside
-Transforms sound waves into electrical impulses
Utricle and Saccule
-Filled with fluid and hairs
-Provide information about body position at rest
Semicircular canals
-Provide information about body in motion
The big four ear complaints
Hearing loss, equilibrium or balance problems, Dizziness/vertigo, Tinnitus (auditory paresthesia)
Cauliflower ear
-Result of physical trauma to the pinna or inflammation or infection
-Can create permenent deformity in the shape of the pinna
-Palpates as a hard lump
-Common in wrestlers and boxers
Perichondritis
Another name for inflammation or infection of the external ear
-Treated with astingents and systematic antibiotics
-Drainage when necessary
Ear piercing
-Earlobe is safer than cartilage (poorer circulation)
-Refer patients id there is swelling, inflammation, infection or fluid filled lesion
Keloid vs Hypertrophic scarring
Keloid: Scar tissue (more excessive and permenent)
Hypertrophic scarring: More temporary
Outer ear infection: Swimmers Ear
-Otitis externa
-Infection or inflammation of the ear canal
-Symptoms: itching, swelling, pain, tenderness, discharge and occasionally hearing loss
Examination Findings in Otitis Externa
Pain when pressing or manipulating the tragus
Medical Care for Otitis Externa
Dependent on cause
-Hematoma or abscess is drained
-Antibiotics: Topically and/or systematically
-Anti-Inflammatory drugs
External Auditory Exostosis: Surfer’s Ear
From repeated exposure to cold water, wind and salt water
Cancer of the Pinna/Auricle
-Due to exposure of ear to ultraviolet radiation from sun
-Look for suspicious growths that are new or changing
Cholesteatoma
-A benign tumor near eardrum
-Appears as white mass behind or on eardrum
Symptoms of Cholesteatoma
Hearing loss, dizziness, pressure in ear, ear ache
Treatment of Cholesteatoma
-Surgery to remove growth completely and to reconstruct damaged ossicles or eardrum
-Goal is preserve hearing (and language skills) and equilibrium/balance
Leading cause of pediatric visits to medical doctor
Middle ear infection/otitis media
Why does Otitis media affect kids more
- Anatomy: Kids eustachian tubes are shorter, more horizontal, and narrower
- ## Physiology: Kids immune systems are not as developed
