Session 7 Flashcards
Structures in the external ear?
What lines the canal?
Role?
Pinna
External auditory meatus
Skin
Transmits and focuses sound waves to tympanic membrane
Structures in the middle ear?
Type of cavity?
What lines the cavity?
What tube connects it with oropharynx?
Ossicles
Air filled cavity
Respiratory epithelium
Pharyngotympanic tube (eustachian)
Structures in the internal ear?
Type of cavity?
Cochlea
Semicircular canals
Fluid filled
Non-ontological causes of ontalgia?
TMJ dysfunction-CN Vc
Disease of oropharnyx- CNIX
Facial palsy and red ear?
Cartilage infection?
Ramsey-Hunt syndrome, varicella zoster of facial nerve
Perichondritis
What’s a Pinna haemotoma?
Problem?
Treat?
If left untreated?
Accumulation of blood between cartilage and overlying perichondrium. From blunt injury to Pinna. Subperichondrial haemotoma.
Deprived cartilage of blood and nutrients causing necrosis.
Drainage and re-apposition of two layers.
Fibrosis causing cauliflower ears.
What is the external acoustic meatus lined with?
What’s the canal continuous with?
Makeup?
What does the cartilaginous part consist of?
Keratinised stratified epithelium.
Tympanic membrane.
1/3 is cartilaginous the rest is bony.
Sebaceous glands and hair to protect from foreign objects. And ceruminous glands producing ear wax.
How does the external acoustic meatus clean itself?
Describe otitis externa?
Complication?
Desquamation then epithelium migrates out laterally of tympanic membrane and out of the canal.
Swelling and inflammation of the external acoustic meatus. Caused by exma or pseudomonas aeruginosa.
Malignant otitis externa, in immunocompromised patients where infection inlvolves bone as well.
What does a bulging tympanic membrane suggest?
Evidence of fluid/bubbles and retraction of tympanic membrane?
Acute otitis media
Glue ear/ otitis media with effusion
Describe a cholesteatoma
Symptoms?
Complication?
Retraction of Pars Flaccida (top of tympanic membrane) causing crusting due to increase negative pressures in the Eustachian tube (chronic dysfunction of tube usually). The retraction traps stratified squamous and keratin which can proliferate and erode through all structures.
Smelly otorrhea and hearing loss but painless.
Can erode bone such as mastoid process and ossicles.
Role of ossicles?
Roles of tensor tampani and stapedius?
Amplify and relay vibrations from the tympanic membrane to the oval window of the Cochlea. Transmits vibration to waves in fluid medium.
contracting if noise is too loud to protect.
What is otosclerosis?
Ossicles fused at articulations due to abnormal bone growth usually between base plate of stapes and oval window. So sound vibrations not effectively transmitted to cochlea so conductive loss of hearing in young adults.
Role of phrayngotympanic tube? (Eustachian)
Equilibrates pressure of middle ear with atmospheric pressure. Also allows ventilation and drainage of mucus from middle ear intomoropharynx.
Describe otitis media with effusion (glue ear)?
Treat?
Can predispose infection due to stagnation of fluid,usually from Eustachian dysfunction. The build up of fluid and negative pressure in the middle ear descreases mobility of TM and ossicles affecting hearing.
Usually resolved in 2/3 months. But if effecting speech then grommets which are tubes to maintain equilibrium pressures.
Describe acute otitis media?
Symptoms?
Cause?
Middle ear infection
Otalgia,temperature
Usually viral but can be strep.p or Haemophillis influenza