ears

auricle and pinna

consists of moveable cartilage and skin

characteristic shape serves to funnel sound waves into its opening, whihc is called the external auditory canal

auditory canal

• A cul-de-sac 2.5 to 3 cm long in adults that terminates at eardrum, or tympanic membrane

• Lined with glands that secrete cerumen, a yellow waxy material that lubricates and protects ear

outer one third of canal is cartilage

• Inner two thirds consist of bone covered by thin sensitive skin.

• Lymphatic drainage of external ear flows to parotid, mastoid, and superficial cervical nodes.

tympanic membrane is called

eardrum, separates external and middle ear

tm

• Translucent membrane with a pearly gray color

• Oval and slightly concave, pulled in at its center by one of middle ear ossicles, the malleus

• Parts of malleus show through translucent drum: umbo, manubrium (handle), and the short process.

• Parts of malleus show through translucent drum: umbo, manubrium (handle), and the short process.

• Pars flaccida: small, slack, superior section of TM

• Pars tensa: remainder of TM, thicker, and more taut

• Annulus: outer fibrous rim of the TM

tiny bit filled cavity inside temporal bone

• Contains tiny ear bones, or auditory ossicles: malleus, incus, and stapes

• Several openings are present.

  • the outer ear covered by the tympanic membrane, 

  • the inner ear via the oval window

  • the eustachian tube which connects the middle ear with nasopharynx and allows for passage of air

    • Normally closed, but opens with swallowing or yawning

the function of the middle ears

• Conducts sound vibrations from outer ear to central hearing apparatus in inner ear

• Protects inner ear by reducing amplitude of loud sounds

• Eustachian tube allows equalization of air pressure on each side of TM so that it does not rupture.

the function and structure of inner ear

Contains the bony labyrinth, which holds sensory organs for equilibrium and hearing.:Vestibule and semicircular canals within bony labyrinth compose the vestibular apparatus. Cochlea contains central hearing apparatus.

Although the inner ear is not accessible to direct examination, its functions can be assessed.

hearing

• Auditory system can be divided into three levels: Peripheral, brainstem, and cerebral cortex

  • At peripheral level, ear transmits sound and converts its vibrations into electrical impulses, which can be analyzed by brain.

amplitude

loudness

frequency

pitch or number of cycles per second

sound waves produce vibrations on tm

• Numerous fibers along basilar membrane are receptor hair cells of organ of Corti, the sensory organ of hearing.

• As hair cells bend, they mediate vibrations into electrical impulses, which are conducted by auditory portion of cranial nerve VIII to brainstem.

Function at brainstem level is binaural interaction

• Locates direction of a sound in space, as well as identifying the sound

• Cranial nerve VIII from each ear sends signals to both sides of brainstem, which are sensitive to differences in intensity and timing of messages from two ears, depending on way head is turned.

• The function of the cortex is to interpret meaning of the sound and begin appropriate response.

pathways of hearing

• Normal pathway of hearing is air conduction (AC) described previously; it is the most efficient.

• Alternate route is by bone conduction (BC): Bones of the skull vibrate and are transmitted directly to inner ear and to cranial nerve VIII.

conductive hearing loss: mechanical dysfunction of external or middle ear

• Partial loss because a person is able to hear if sound amplitude is increased enough to reach normal nerve elements in inner ear

• May be caused by impacted cerumen, foreign bodies, a perforated TM, pus or serum in middle ear, and otosclerosis

sensorineural (or perceptive ) hearing loss: signifies pathology of inner ear, cranial nerve vll, or auditory areas of cerebral cortex

• Increase in amplitude may not enable a person to understand words.

• May be caused by presbycusis and by ototoxic drugs, which affect hair cells in cochlea.

hearing loss

• Mixed hearing loss: combination of conductive and sensorineural types in the same ear

Equilibrium

Labyrinth in inner ear constantly feeds information to brain about body’s position in space.

Labyrinth

• Three semicircular canals

• If labyrinth ever becomes inflamed, it feeds wrong information to brain, creating a staggering gait and vertigo.

otosclerosis

• Common cause of conductive hearing loss in young adults between ages of 20 and 40

• Gradual hardening that causes footplate of stapes to become fixed in oval window: Impeding transmission of sound and causing progressive deafness

in again persons

• cilia lining ear canal become coarse and stiff

Stiff cilia

• May cause cerumen to accumulate and oxidize, which greatly reduces hearing

• Cerumen is drier with aging because of atrophy of apocrine glands.

• Impacted cerumen is a common but reversible cause of hearing loss in older people.

Presbycusis

type of hearing loss that occurs with aging, even in people living in quiet environment

Gradual sensorineural loss

caused by nerve degeneration in inner war or auditory by nerve

onset of presbycusis

50s and slowly progresses:First notice a high-frequency tone loss., Ability to localize sound is impaired also.

when unfavorable background noise is present

Accentuated

PCC questions

• How do you clean your ears?

• Last time you had your hearing checked?

• If hearing loss was noted

  • Did you obtain a hearing aid? 

  • How long have you had it? 

  • Do you wear it? 

  • How does it work? 

  • Any trouble with upkeep, cleaning, changing batteries?

During history, notice clues from normal conversation indicating possible hearing loss.

• Lip reading or watching your face and lips rather than your eyes

• Frowning or straining forward to hear

• Posturing of head to catch sounds with better ear

• Misunderstands questions; frequently asks you to repeat

• Irritable or shows startle reflex when you raise your voice

• The person’s speech sounds garbled, vowel sounds distorted

• Inappropriately loud voice

• Flat, monotonous tone of voice

objective equipment

• Otoscope with bright light, fresh batteries give off white, not yellow light.

• Pneumatic bulb attachment, sometimes used with infant or young child

• Tuning forks in 512 and 1024 Hz

Weber test

• Normal finding—sound is equally heard in both ears

• Abnormal finding—sound lateralizes to one ear

• Conductive loss—Sound lateralizes to poorer ear

• Sensorineural loss—Sound lateralizes to better ear

• Rinne test

• Normal finding—AC greater than BC, noted as positive finding

ear abnormalities

• Frostbite

• Branchial remnant and ear deformity

• Otitis externa (Swimmer’s ear)

• Cellulitis

• Carcinoma

frostbite

A condition resulting from freezing of the skin and underlying tissues, often affecting the ears, nose, and fingers.

Symptoms include numbness, tingling, and discoloration, leading to tissue damage in severe cases.

affects subcutaneous tissue

Branchial remnant and ear deformity

facial remanent or left of the embryologic branchial arch usually appears as a skin tag

often in the preauricular area in front of tragus

bilateral increased for renal anomalies

Otitis externa (Swimmer’s ear)

infection of the outer ear

with sever movements of the pinna and tragus redness and swelling of pinna canal scanty purulent discharge itching fever

enlarged tender regional lymphy nodes

canal becomes water clogged and swollen

skin folds for infection

cellulitis

chronic inflammation or infection deep in the dermis and loose subcutaneous connective tissue

signs redness warmth pain thicken hardness of auricle diffuse borders

ear canal abnormalities

• Excessive cerumen

• Otitis externa

• Osteoma

• Foreign body

• Exostosis

• Furuncle

• Polyp

Excessive cerumen

90-95% blocked narrow

can expand in shower or swimming

fullness can cause sudden hearing loss

Otitis Externa

sever swelling of Cana inflammation tenderness

canal lumen in narrowed one-fourth normal

foreign body

beans corn breakfast cereal jewelry beads small stones sponge rubber for kids

cotton for adults

osteoma

single hard rounded nodule

nontender overlying skin that grows in the ear canal, typically benign, and may cause hearing loss.

exostosis

more common than osteoma

smalll bony hard round nodules

arise near ear drum do no obstruct the view

multiple bilateral occurs more frequent in cold water swimmers

needs no treatment

cerumen may accumulate and cause to block the canal

polyp

arise in canal from granulomatous or muscoal tissue

reder than areas bleeds easily

purulent discharge indicated chronic ear disease

benign but refer for excision

furuncle

exquisitely painful red infected hair follicle

occur on tragus or cartilaginous of ear

regional lymphadenopathy

Abnormalities of Tympanic Membrane

• Retracted drum

• Otitis media with effusion (OME)

• Acute otitis media 

• Perforation

• Insertion of tympanostomy tubes

• Cholesteatoma

• Scarred drum

• Blue drum (hemotympanum)

• Fungal infection (otomycosis)

• Bullous myringitis

retracted drum

looks more prominent and defined

malleus handle looks shorter and more horizontal than normal

short process is very prominent

light reflex or disoriented

the drum is dull and lusterless and does not more

due to negative pressure in the middle ear from obstructed Eustachian tube and serous otitis media

Otitis Media With Effusion (OME)

yellow amber drum serum for puss in middle ear that transudes to relieve negative pressure from the blocked eutachain tube

note air/fluid level with a fine black dividing line or air bubbles visible behind ear drum

symptoms are feeling of fullness , transient, hearing loss , popping sound with swallowing

also called serous otitis media , glue ear

Acute otitis media

results when the middle ear lid is infected

absent light reflex from increasing middle ear pressure

readness and bulging are first noted in superior part of ear drum ( pars flaccida), along with earache and fever

throbbing pain possible hearing loss

bulging of eardrum

insertion of tympanovstomy tubes

polyethylene inserted to relieve middle ear pressure and promote drainage if chronic or recurrent middle ear infection

acute infection decreased

tubes reduce risk of speech delay due to conductive hearing loss

extrude spontaneous in 12 to 18 months

scarred drum

dense white patches on the ear drum are sequelae repeated ear infections

they do not necessarily affecting hearing.

Fungal infection (otomycosis)

black or white dots on drum or canal wall

yeast or fungal infection

colony of growth

Perforation

if acute otitis not tread then ear drum may rupture from increased pressure

occurs from trauma

oveal darkened area

central perforation: occur in pars tensa

Marginal perfrations ( attic perfration) : occurs in annulus

attic perfration: occurs in the superior part of ear drum the pars flaccid

• Blue drum (hemotympanum)

indicates blood in the middle ear as trauma resulting in skull fracture

• Bullous myringitis

small vesicles contianing blood on the eardrum

accompanied by mycoplasma pneumonia infection

blood tinge discharge and sever otalgia

Cholesteatoma

an overgrowth of epidermal tissue in the middle of the ear or temporal bone may perforation

white cheesy appearance

growth of cholesterol can cause erode bone produce hearing loss

early signs otorrhea otalgia unilateral conductive hearing loss , tinnitus

Lumps and lesions abnormal

battle sign

carcinoma

• Sebaceous cyst

• Tophi

• Chondrodermatitis nodularis helicis

• Keloid

battle sign

ecchymotic discoloration posterior of the pinna and over mastoid process

• Chondrodermatitis nodularis helicis

painful nodules develop on the rim of helix

due to repeptive trauma or pressure on the ear.

small indurated dull red poorly defined very painful

• Sebaceous cyst

being the lobe

nodule with central black puncture indicates blocked sebaceous gland

filled with waxy material painful if it becomes infected

often multiple

Top

small yellow whitish hard nontender nodules

near helix or antithelix contain greasy chalky material due to blockage of sebaceous glands.

sign of gout

carcinoma

ulcerated crusted nodule

fails to heal

bleed intermittently

superior of pinna maybe ear canal chronic discharge