ear Flashcards
3 major sections of the ear
Outer or external ear.
Middle ear or tympanic cavity.
Inner ear or labyrinth.
Each section transmits sounds differently.
external ear
Conducts sound waves through air. Includes: Auricle (or pinna) . External auditory canal (or ear canal). Cerumen. Tympanic membrane (or eardrum).
auricle (pinna)
Collects waves traveling through air.
Channels sound waves to the external auditory canal.
external auditory canal
Slender tube lined with glands that produce a waxy secretion called cerumen.
cerumen
Sticky secretion that traps tiny foreign particles.
Prevents particles from entering deeper areas of the canal.
tympanic membrane
Flat, membranous structure drawn over the end of the ear canal.
Sound waves strike the TM, causing it to vibrate.
Movement of the TM causes movement of the three smallest bones of the body, collectively called the ossicles.
middle ear
Conducts sound waves through bone.
Includes:
Eustachian Tube
Ossicles: Three smallest bones of the body: Malleus ,Incus, Stapes
Located in the tympanic cavity.
Form a coupling between the TM and the cochlea.
These 3 bones articulate sound.
eustachian tube
Connects the middle ear to the pharynx.
Equalizes pressure on the outer and inner surfaces of the eardrum (TM).
When sudden pressure changes, pressure can be equalized on either side of the tympanic membrane by deliberate swallowing.
malleus
Aka: Hammer.
Attached to the TM.
Articulates with the incus.
incus
Aka: Anvil.
Located between the malleus and the stapes.
stapes
Aka: Stirrups.
Attached to the oval window of the cochlea.
Articulates with the incus.
inner ear
Conducts sound waves through fluid. Includes: Cochlea. Also includes the structures for equilibrium: Semicircular canals. Vestibule.
cochlea
Snail-shaped structure.
Filled with fluid called perilymph.
Inner surface lined with highly sensitive hearing structures called the organ of Corti.
Organ of Corti contain tiny nerve endings called hair cells.
Movement of the ossicles causes the stapes to exert a gentle pumping action against the oval window.
Pumping action forces the perilymph to disturb the hair cells.
Generates impulses that are transmitted to the brain via the auditory nerve.
Brain interprets impulses as sound.
equilibrium: inner ear (Labyrinth)
Located in the inner ear.
Consists of a system of fluid-filled tubes and sacs; as well as nerves that connect these structures to the brain.
equilibirum
Labyrinth located inside the bone of the skull.
Includes: Cochlea and the vestibular system (includes the vestibule and the semicircular canals).
equilibrium: vestibular system
Controls balance, posture, orientation, body response to movement and eye movement.
Contains: Semicircular canals and the vestibule.
Vestibule joins the cochlea and semicircular canals.
otitis media
Inflammation or infection of any part of the outer, middle, or inner ear.
Otitis media (middle ear) is the most common.
Inflammation begins when infections that cause sore throats, colds or other respiratory or breathing problems spread to the middle ear.
Can be bacterial or viral.
Most commonly found in children.
symptoms of otitis media
Pain in ear. Child may tug or pull one or both ears. Unusual irritability. Difficulty sleeping. Fever. Fluid draining from the ear. Loss of balance. Difficulty hearing.
treatment of otitis media
Antibiotics.
Pain and fever reducing medications.
Decongestants.
Antihistamines.
Tonsil and adenoid removal for frequent sufferers.
Pressure-equalizing (PE) tubes surgically implanted through the TM, for frequent sufferers. PE tubes remain in ear about 9-months, and then fall out. If not, surgically removed by age 5-6.
prevention of otitis media
Do not expose children to second hand smoke.
Avoid sick playmates.
Nursing infants have lower incidence of OM.
Have infant in upright position for bottle feeding.
Use of decongestants and antihistamines , prophylactically.
tinnitus
Perception of ringing, hissing, or other sounds in the ears or head when no external sound is present.
A symptom associated with many forms of hearing loss.
People with severe cases may find difficulty in hearing, working and sleeping.
possible causes
Hearing loss.
Too much exposure to loud noises.
Medicine: More than 200 medicines (i.e.: large doses ASA) can cause tinnitus.
Blow to the head.
Health problems: Allergies, tumours, impacted wax, anaemia, hypertension, stress, neck and jaw problems.
treatment for tinnitus
No cure. Symptomatic relief only. Hearing aids. Maskers. Medicine or drug therapy: Antiarrhythmics and antidepressants.
vertigo
Hallucination of movement, or a feeling of spinning or dizziness.
Loss of balance.
May lead to nausea and vomiting.
possiblle causes Variety of disorders. Ménière’s disease. Lesion or other process affecting the brain, or eighth cranial nerve. Labyrinthitis.
treatment for vertigo
No cure. Symptomatic relief only. Antihistamines. Antibiotics. Dietary changes. Stress management.
meniere’s disease
Abnormality of the inner ear causing many symptoms: Vertigo, severe dizziness, tinnitus, fluctuating hearing loss, sensation of pressure or pain in the affected ear.
Loss of balance.
May lead to nausea and vomiting.
symptoms of menieres
Can occur suddenly and arise daily, or as infrequently as once a year. Occurs without warning. Vertigo, severe dizziness. Nausea, vomiting. Sweating. Tinnitus. Hearing loss. Headache. Abdominal discomfort. Diarrhea. Attacks may last for minutes or hours.
possible causes Symptoms associated with a change in fluid volume within the labyrinth portion of the inner ear. Head injury. Rupture of the membranous labyrinth. Noise pollution. Viral infections.
treatment for menieres
No cure.
Symptomatic relief only.
Antihistamines.
Antibiotics.
Dietary changes to reduce fluid retention in the body.
Stress management.
Labyrinthectomy – controls vertigo, but leads to hearing loss.
otosclerosis
Abnormal hardening (ankylosis) of bones of the middle ear that causes hearing loss. Ossicle most commonly affected is the stapes.
symptoms of otosclerosis
Progressive hearing loss, especially of low tones.
Tinnitus.
Dizziness.
Vertigo
possible causes
genetics
treatment for otosclerosis
Surgical correction: Removing part of the stapes, (a stapedectomy, or commonly, a stapedotomy) and implantation of a prosthetic device that allows sound waves to pass to the inner ear.
dextra
right
sinistra
left
pertaining to the ear
auricular
Rinne test
test using a turning fork to measure hearing by comparing results of bone conducting and air conduction
salping/o
root word for Eustachian tube
pathway of sound
malleus, incus, stapes, cochlea
which part of the ear contains cerumen
external auditory canal
posterior portion of cornea
sclera
Weber test
test that assesses bone conduction of sound in the ear
semicircular canals
fluid filled loops in the labyrinth that gives the body sense of balance
otitis media
ear infection (inflammation of the ear)
