Auditory And Vestibular Systems Flashcards
Function of the external ear
To funnel sound waves into the ear canal causing a vibration of the eardrum
Vibration of thr tympanic membrane causes what
It is magnified at the junction of the stapes it the inner ear to the cochlea and ultimately to the hair cells in the organ of corti which then go to the cochlear ganglion
What is the reflex involving the SON that protects the hair cells from damage and what cranial nerves are involved
???
What is the primary auditory cortex area number
41
Where is area 41 located
The transverse temporal gyri of heschl
What is the funcion of area 41
It is the auditory cortex responsible for the subjective experience of sound
What is the function of wernickes area
The interpretation of sound
Where do the central processes of the spiral ganglion neurons enter the CNS and synapse
The dorsal or vestibular cochlear nuclei int he dorsal and lateral rostral medulla
What are some of the nuclear groups involved int audition
The SON, nuclei of the lateral lemniscus and or the trapezoid body, and the inferior colliculus
How is the inferior colliculus involved in the pathway that always us to hear and interpret sounds
Inferior colliculus projects to the medial geniculate nucleus of the thalamus, which projects ipsilaterally to area 41 int he temporal lobe.
Conductive hearing loss
A loss in hearing due to some obstruction which prevents sound waves from reaching the cochlea
Sensory-neural hearing loss
Occurs when neurons or their processes are damaged in the PNS or CNS
Most unilateral lesions do not produce significant hearing loss
Unilateral lesions above the medulla which involve the auditory nuclei/pathway produce what
A bilateral diminution of hearing slightly more contralateral than ipsilateral but not deafness!!
What is the acoustic reflex
The way your brain prevents hair cells from being damaged in the cochlea via CN 5 and 7
Presbycusis
The accumulated loss of hair cells causing a decreased auditory acuity
If a patient hums and they hear better in the ear which shows damage they…
Have obstructive hearing loss
If a patient hums and they hear the hum under in the “good” ear they have…
Sensori-neural hearing loss
Where are the cell bodies of origin in the vestibular system
The vestibular ganglion
The medial and superior vestibular nuclei send their axons where
To the medial longitudinal fasiculus to connect with the motor nuclei of 3,4,6
Benign paroxysmal positional vertigo
The accumulation of little calcium carbonate crystals on the vestibular apparatus
What is the maneuver associated with BPPV
The Epley Maneuver
Meniere’s disease clinical triad
Fluctuating unilateral sensori-neural hearing loss, tinnitus, and vertigo due to an excess fluid in the inner ear
Acoustic neuroma/vestibular neuroma
Schwannoma
A schwann cell tumor in the PNS that, if left unchecked, will compromise both divisions producing ipsilateral sensori-neural hearing loss, tinnitus, and vertigo
Tumors of the cerebelopontine angle
Triad
Ipsilateral deafness, loss of the corneal reflex, and ataxia=the triad
Facial weakness and sensory loss may also be present ipsilaterally due tot he presence of CN 7
