Neuro: Auditory And Vestibular Systems Flashcards
Conductive hear loss:
Occurs due to damage to the external and middle ear
Possible causes of conductive hearing loss:
- Obstruction
- Otosclerosis
- Otitis media
What is obstruction in conductive hearing loss?
Blockage by wax or a foreign body in the external auditory meatus
What is otoscleroisis in conductive hearing loss?
Produced by neogenesis of gathering labyrinthine spongy bone around the oval window, resulting in fixation of the stapes
What is otitis media in conductive hearing loss?
Inflammation of the middle ear
- most common cause of meningitis and most common cause of brain abcess
What is sensorineural hearing loss?
Damage t the inner ear (cochlea), cochlear nerve, or the central nervous system will produce sensorineural loss
What is the most common form of hearing loss?
Presbycusis
Presbycusis results from
Degenerative disease of the organ of Corti in the first few millimeters of the basal coil of the cochlea
What is the organ of Corti?
Receptor organ for hearing
How do outer hair cells affect sound?
Manipulate the basilar membrane to enhance sensitivity and precision of inner hair cell tuning
Basilar membrane:
Main mechanical element in the inner ear
-functions as a frequency analyzer
What ion is used for depolarization of hair cells
Potassium
The central cochlear nucleus has
Bilateral projections in the medulla
Damage along the hearing pathway from the superior olivary nucleus up causes
Issues but not complete deafness
The bilateral projections are important because
you won’t have complete hearing loss if damage happens, allows for localization!
Semicircular canals sense what type of movement?
Rotational head movements such as tilting, nodding, or shaking
What type of movement do utricles sense?
Tilt when the head is upright and horizontal acceleration
What type of movement do sacculars sense?
Til it when the head is horizontal and more sensitive to vertical acceleration
Left rotation of the head causes the horizontal semicircular canal to excite and inhibit what?
-Excitation of left hair cells and vestibular nerve
-inhibition of the right hair cells and vestibular nerve
