Test 2 Flashcards
Cochlear Nucleus
Medulla; A collection of neuron bodies with similar structure, function and pathway.
Superior Olivary Complex
Pons; receives information from both ipsi- and contra-lateral cochlear nuclei; 1st place of binaural input
Lateral Lemniscus
Pons; primary auditory pathway; a tract not a structure
Inferior Colliculus
Midbrain; all auditory fibers must pass through the IC; may be involved at the level of the thalamus; the thalamus itself is a relay station for almost all sensory information
Auditory Cortex
Cortex; where sound is processed; lies on the upper surface of temporal lobe; can’t be seen on lateral surface of cortex must displace temporal lobe
what is the primary auditory cortex called
heschl’s gyrus
what is wernicke’s area?
contains the supramarginal gyrus and angular gyrus. recognition of linguistic stimuli and comprehension of spoken language. integration of information
organ of corti
is a gelatinous and fibrous flap (tectorial membrane) the outer hair cells are embedded in the pectoral membrane whereas the inner hair cells are not.
oval window
top
round window
below where it terminates
how is frequency organized in the cochlea?
tone of topic organization (goes around in a spiral)
high frequencies - base
low frequencies apex (middle part)
what are inner hair cells
send sound to brain; 1 row; around 3500
what are outer hair cells
help move the tectorial mechanical properties; 305 rows; around 12,000
what is the basilar membrane
dividing wall in chamber
what is the middle pillar of bone
medilas
what are the chambers of the cochlea
scala vestibuli- top chamber; contains perilymph
scala media- middle chamber; contains endolymph
scala tympani- bottom chamber; contain perilymph
what is another name of the cochlea
otic capsule
where specifically is the cochlea located
inner ear; cochlear duct
what are the dimensions of the cochlea
2 3/4 turns- spiraled; like a snail shape; widest at the base; narrowest at the apex. around 35 centimeters
what is the Eustachian tube?
opens and closes to equalize pressure between middle ear and environment; remains lightly closed until a sneeze or cough or swallow or yawn opens the tube. when it is open, it is said to be patent. when it shuts off (swells around opening), it creates a vacuum in the ME cavity and causes serum (fluid) to fill that space. this is the otitis media with effusion (fluid)
what are the ossicles
mallius, inchus, and stapes
what is the umbo?
center portion; it is concave because the malleus bone and manubrium is attached to the tyrannic membrane
what is the cone of light
due to the conical shape light reflects anteroom-inferioly from the umbo
what are the layers of the tyrannic membrane?
innermost- mucosal
outermost- epilitum
middle- fibrous
what are the parts of the tympanic membrane?
pars tensa (bigger) and pars flaccida
where is cerumen produced
ear canal- outer portion (cartilage) also called wax
