Quiz 1 Flashcards
(39 cards)
What are the names of the ossicles?
Malleus, Incus, Stapes
What opens the Eustachian Tube?
Active contraction of the tensor veli palantini during swallowing or yawning.
Which Labyrinth is filled with perilymph?
The bony Labyrinth is filled with perilymph that is essentially extra cellular fluid (high in sodium and low in potassium).
Which Labyrinth is filled with Endolymph?
The membranous labyrinth is filled with endolymph, the only extra cellular fluid in the body high in potassium and low in sodium.
Functions of the cochlea?
Primarily for the conversion of sound energy into electrical energy. The vibrations from the ossicles set the endolymph into motion, which causes a flow of positive ions (K+), across the negatively charged hairs on the organ of Corti, causing a synapse to fire. This information is conveyed by the 8th cranial nerve to the auditory area of the temporal lobe where it is interpreted as sound.
Functions of the vestibule?
Semi-circular canals: primarily for proprioception and balance
Functions of stria vasicularis?
The inner ear has a unique vascular system. It is the only vascularized epithelium in the body. The cells of the stria vascularis are high in mitochondria.
Acts as a back up “battery for the organ of Corti, helps to maintain endolymph. Its vascular supply provides nutrients to the organ of Corti while keeping the vessels at a distance minimizing the distraction of noise from blood flow.
LICHEN SIMPLEX CHRONICUS (Neurodermatitis)
Itch/scratch cycle continues after initial insult such as bug bite. Most commonly found in outer canal and concha.
Treatment: education, cut nails, soothing lotion
SEBORRHEIC DERMATITIS
Scaly Erythema & lesions on scalp and eyebrows
CONTACT DERMATITIS
Irritants to ear, such as perfume and earrings (nickel)
ATOPIC DERMATITIS
Atopic Patient (eczema, asthma, hayfever). Look for lesion on flexion folds, ear canal. Can be confused with otitis externa, but is sterile, no WBC, not infected.
What is the atopic dermatitis triad?
Eczema, Asthma, Allergies (Hayfever)
ACUTE CELLULITIS
Secondary to another dermatitis or trauma. Cellulitis is a more superficial infection - small area that is red, hot usually caused by Group A β hemolytic streptococci (GABHS) less commonly by Staphylococcus aureus;
ERYSIPELAS
Erysipelas is a deeper infection that spreads along facial planes and will involve the whole auricle. Patient will be sicker- fever, chills.
INFECTIOUS CHONDRITIS
Deeper infection involving cartilage usually follows erysipelas. Entire ear red, hot, including lobe. Also systemic symptoms: fever, nausea, chills.
RELAPSING POLYCHONDRITIS
Non-infectious systemic disease, bilateral auricular chondritis. Redness comes not from skin, but deeper; possibly autoimmune; Will have other symptoms, such as nasal chondritis, ocular chondritis or arthritis; * Spares the lobes; Redness is only where there is cartilage;
AURICULAR HEMATOMA (TRAUMA)
Boxer, wrestlers, rugby players; Must treat quickly to prevent formation of cauliflower ear;
Treatment: remove fluid with 18g needle & 10 cc syringe then cover with compression dressing for 48 hrs.
MALIGNANT OTITIS EXTERNA
Indolent (slow) progressive otitis externa that invades the underlying cartilage. Rare but dangerous. It affects immunocompromised individuals, particularly those who have diabetes., alcoholic, severe malnourished.
S/Sxs of Malignant OE
ear pain, purulent d/c from canal, no fever, no swelling; Looks benign compared to the symptoms, but at junction of temporal bone inside canal you may see granulation tissue. The most common causative agent remains Pseudomonas aeruginosa. Can go through cartilage to bone causing osteomyelitis, hearing loss and facial nerve paralysis and death. Test facial nerve function.
Management of Malignant OE
ENT referral: Definitive diagnosis requires a high index of suspicion. Diagnosis is aided with an abnormal MRI or CT scan showing extension of infection into bony structures. Biopsy may be performed to provide histologic exclusion of malignancy. Long-term oral antipseudomonal agents have proven effective; however, pseudomonal antibiotic resistance patterns have emerged.
Adjunctive therapies, such as aggressive debridement and hyperbaric oxygen therapy, are reserved for extensive or unresponsive cases.
Acute otitis media (AOM)
Usually secondary to a URI, much more common in children under 10 years.
Usually unilateral, starts with a sensation of blockage, hearing loss Progresses to fever, pain increases < evening, causes deep severe pain Insomnia, irritability, anorexia (best clues in infants).
Physical exam needed for AOM
(rectal Temp > 100.4o F or oral temperature > 99.5o F), Middle ear fluid as revealed by pneumatic otoscopy, tympanic erythema, loss of normal landmarks, light
reflex is smaller and distorted. May have fever and cervical lymphadenopathy. Fullness or bulging of the tympanic membrane(s) are insensitive but specific signs.
OTIC BAROTRAUMA
Otic barotrauma occurs during air travel typically, less commonly scuba diving. Otic Barotrauma is defined as inflammation of the middle ear caused by the pressure difference between the air in the middle ear and the external atmosphere, developing after ascent or more commonly on descent. Predisposed by Eustachian Tube dysfunction (allergies, colds, serous otitis media) 5; Otalgia can be severe with ear fullness, < yawning, hearing loss and dizziness. Severe cases may result in tympanic membrane perforation and even round window membrane rupture
IMPACTED CERUMEN
Symptoms:
Vague discomfort to severe pain; impaired hearing, other symptom can include dizziness, ear fullness, reflex cough. There may be a history of “Q-tip abuse”, and increased cerumen production.
