13 - Anatomy of the Ear Flashcards
What can be some signs and symptoms of ear disease?
How can the different parts of the ear be split up?
External, Middle, Inner
What nerves carry general sensation to the ear and why is this important?
- Referred pain to the ear for lots of disorders
- CN VIII carries special sensory
If you had otalgia but a normal ear examination what are some differentials you can suspect?
-
What is the function of the external ear?
What are some causes of pinna abnormalities and using the pictures what would be the diagnosis?
What is Ramsey Hunt syndrome?
- Shingles of the facial nerve (V.Zoster)
- Facial nerve palsy always check ear
What can be the complications of a pinna haematoma and how do you treat it?
- Blunt injury can cause subperichondrial haematoma, stripping perichondrium and blood supply from cartilage
- Pressure necrosis
- Need to drain and reappose two layers using rolls otherwise will get fibrosis and asymmetrical cartilage formation so cauliflower ear
What is the structure of the external acoustic meatus?
- Lined with same epithelia as skin to lateral surface of tympanic membrane
- Outer third cartilage, inner two thirds bony
- Sigmoid so pull back, up and out to straighten to see tympanic membrane
- Hair, sebaceous and ceruminous glands on cartilage part not bony
- Epithelial migration to clean
Label the following pathology of the tympanic membrane.
What is the angle of the tympanic membrane normally and what is some pathology that can affect this angle?
If you see this when examining a tympanic membrane what should you suspect, and what is the pathogenesis of this disease?
Cholesteatoma
- Chronic ET dysfunction causes -ve pressure to pull pocket into middle ear as no equillibrium of pressure
- Retraction of pars flaccida forms pocket trapping keratin and stratified sqaumous epithelium which proliferates and forms cholesteatoma
- Painless, smelly ottorrhea +/- hearing loss*
- Slow grows and can enzymatically destroy bones like ossicles, mastoid, cochlea to brain
What is the function of the middle ear?
- Amplify and vibrate fluid from TM to oval window of cochlea
- Ossicles connected by synovial joints and tampered by tensor tympani and stapedius in accoustic reflex
What nerves are involved in the acoustic reflex?
What is otosclerosis?
- Common cause of acquired hearing loss in middle ear in young adults, ?genetic and environmental viral causes
- Ossicles fuse at articulations due to abnormal bone growth, usually at base plate of stapes
- Sound vibrations cannot be transmitted as well
- Gradual uni/bilateral conductive hearing loss
What are some symptoms of otosclerosis?
- Usually bilateral
- Will become totally deaf if not treated