Norden - Auditory And Vestibular Systems Flashcards
Nerve impulses for hearing arise in the
Organ of corti
This nucleus sends axons down CN VIII directly to the hair cells in the organ of Corti or to spiral ganglion neurons.
It allows for specific sounds (such as human speech) to be accentuated
Superior Olivary Nucleus (SON)
Why are the many individual nuclei that are involved in synapse of audition of little clinical consequence ?
The connections in the auditory system are bilateral
Where is the primary auditory cortex?
Temporal lobe
Unilateral lesions of the peripheral auditory nerves or from lesions of the dorsal and ventral cochlear nuclei at the medulla causes/
Unilateral sensorineural deafness
Unilateral lesions above the medulla involving the auditory nuclei/ pathways produces?
Bilateral dimunition of hearing with slightly more loss contralateral to lesion, but not complete deafness
What nerves and muscles are involved in the acoustic reflex, which serves to protect hair cells from loud sounds by stiffening the ossicular chain?
V3 - tensor tympani
VII - stapedius
Sensorineural hearing loss primarily due to an accumulated loss of hair cells. In elderly.
Loss of hearing at high frequency, which makes it difficult to understand the sounds of speech clearly
Presbycusis
Vertigo
Room spinning
How big is optic disc?
1.5 mm diameter
Cell body of origin for vestibular system?
Scarpa’s (vestibular) ganglion
Involuntary oscillatory or jerking movement of the eyes
Nystagmus
S/s involvement of vestibular system
Vomiting, postural inbalance, nausea, nystagmus, vertigo
What is the cause of benign paroxysmal positional vertigo?
As we age, calcium carbonate crystals can be precipitated out of the fluids of fluids in the vestibular system. these can lodge in the semicircular canals and cause pt’s have abhorrent signaling. This can be improved by epley maneuver
Clinical triad of Meniere’s disease
Fluctuating unilateral sensorineural hearing loss
Tinnitis
Vertigo
