Lecture 6 The Physiology and Clinical Aspects of Hearing and Balance Flashcards
What is Otitis media with effusion
Thick viscous fluid in middle ear that prevents ear drum from moving and causes conductive hearing loss
What is Ostosclerosis
Deposition of new bone where footplate of stapes fits into oval window which reduces movement of stapes leading to conductive hearing loss
How can hearing be assessed
- Clinical testing
- Tuning fork tests
- Audiometry
- Objective testing
Name the 2 types of tuning fork tests
Weber
Rinne
What is the Weber Test
A test of lateralisation (hold fork in centre of skull/forehead)-conducts to the poorer ear when humming
What is the Rinnes Test
a test that compares loudness of perceived air conduction to bone conduction in one ear at a time sensory and normal- air conduction
What type of audiometry tests are there?
Pure tone
Visual reinforcement audiometry
Play audiometry
What us Tympanometry
assists in the detection of fluid in the middle ear, perforation of the eardrum, or wax blocking the ear canal. Tympanometry pushes air pressure into the ear canal, making the eardrum move back and forth. The test measures the pressure within the middle ear and the mobility of the eardrum.
What is otoacoustic emissions
are sounds given off by the inner ear when the cochlea is stimulated by a sound
Would someone with hearing loss produce otoacoustic emissions?
No
What is the air-bone gap
When bone conduction perception is greater than air conduction perception
What can be done to manage hearing loss
Surgery
Hearing aid
BAHA
Cochlear implant
What is BAHA and when is it used
Bone anchored hearing aid
Used by those who’s anatomy makes use of conventional aid difficult e.g. persistent otitis external, external canal atresia
What is a Cochlear implant
Avoids inner and middle ear and directly stimulates neurons
What are the types of hearing loss
Conductive
Central
Sensorineural
Name the 2 otolith organs
Utricle and Saccule
What sensory epithelium do the utricle and saccule contain
Macula
How is the macula orientated in the utricle and saccule
Horizontally- utricle
Vertically- saccule
What is found in the macculae
Cilia of hair cells embedded in gelatinous otolithic membrane that contains calcium carbonate crystals called otoliths
What is located at each end of the semi-lunar canals
Enlarged chamber called ampulla which contains sensory structure called crista
What does crista contain
Hair cells and gelatinous mass, the Cupula
Movement of the crest is the stimulus for what
Vestibulo-ocular reflex
Define the vestibular-ocular reflex
• The VOR stabilises gaze by moving eyes in order to compensate for head and body movement by moving eyes in the opposite direction. This fixes image on retina for clear sight.
Name clinical conditions of inner ear that affect balance
BPPV
Vestibular neuritis
Meniere’s Disease
What produces endolymph
Stria vascularis
