Control Lecture 4: Auditory pathway Flashcards
Which part of the temporal bone is the ear located within?
Petrous part
Which cranial nerves pass through the internal acoustic meatus?
Facial (VII)
Vestibulocochlear (VIII)
What is the outer part of the ear that captures sound waves called?
Pinna/Auricle
What connects the middle ear and the nasopharynx?
Eustachian/pharyngotympanic/auditory tube
Via what structure can infections pass from the middle ear to the middle cranial fossa?
Mastoid air cells
Which blood vessel passes inferiorly to the middle ear?
Internal jugular vein
Which blood vessel passes anterior to the middle ear?
Internal carotid artery
What does the position of the internal carotid artery put the ear at risk of?
Pulsatile tinnitus
Which structures traverse the middle ear?
Facial canal
Chorda tympani
What are the three cavities in the inner ear?
Vestibule
Semi-circular canals
Cochlea
What are the three bones in the inner ear, in order of superficial to deep?
Malleus
Incus
Stapes
What structure does the stapes hit to transmit sound waves?
Oval window
What do the cavities of the inner ear contain?
Perilymph
Is perilymph similar to intra or extra cellular fluid? Why?
Extra cellular
High Na+ concentration, low K+ concentration
What does the cochlear duct contain?
Endolymph
Is endolymph similar to intra or extra cellular fluid? Why?
Intra cellular
High K+ concentration, low Na+ concentration
What is the cochlea above the cochlear duct called?
Scala vestibuli
What is the cochlea below the cochlear duct called?
Scala tympani
What is the apex of the cochlea called?
Helicotrema
What is the final structure at the termination of the scala tympani?
Round window
What is the roof of the cochlear duct made by?
Vestibular membrane
What is the floor of the cochlear duct made by?
Basilar/basement membrane
What is the sensory receptor in the cochlear duct, and which membrane is it on?
Spiral organ of Corti
Basilar membrane
What is the name of the membrane that covers the spiral organ of Corti?
Tectorial membrane
What are the tips of the hair cells from the spiral organ embedded?
Tectorial membrane
Where does the vestibulocochlear nerve enter the brainstem?
Cerebellopontine angle
Where is the primary neuron cell body in the ascending auditory pathway?
Spiral ganglion
Where is the first synapse in the ascending auditory pathway?
Cochlear nuclei
What aspects of auditory inputs are compared to locate the origin of sounds?
Differences in time and volume between the two ears
Through what structure do auditory neurons cross over the midline to become bilateral?
Trapezoid body
What structures does the auditory pathway pass through between the cochlear nuclei and the primary auditory cortex in the brain, and where are they located?
Superior olivary nuclei - pons
Inferior colliculus - pons
Medial geniculate nuclei - thalamus
What bilateral structures in the auditory pathway are able to communicate, contrary to the pathway mainly being seperate once it becomes bilateral?
Inferior colliculi
What does the auditory pathway travel in between the superior olivary nuclei and the inferior colliculus?
Lateral lemniscus
What does the auditory pathway travel in between the inferior colliculi and the medial geniculate nuclei?
Inferior brachium
What part of the cerebral cortex is the primary auditory cortex?
Heschl’s gyrus
Which part of the basilar membrane is tighter?
Proximal
Which part of the basilar membrane is looser?
Distal
Which part of the basilar membrane is more sensitive to high frequencies?
Proximal
Which part of the basilar membrane is more sensitive to low frequences?
Distal
Would low or high frequency sound travel to the superficial/lateral part of Heschl’s gyrus?
Low
Would low or high frequency sound travel to the deep/medial part of Heschl’s gyrus?
High
Is Broca’s area located anteriorly or posteriorly in the brain?
Anteriorly
Is Wernicke’s area located anteriorly or posteriorly in the brain?
Posteriorly
Is Broca’s area motor or sensory?
Motor
Is Wernicke’s area motor or sensory?
Sensory
Is Broca’s area associated with production of words or understanding of words?
Production of words
Is Wernicke’s area associated with production of words or understanding of words?
Understanding of words
Which artery are the secondary auditory cortexes supplied by?
Middle cerebral artery
At what point does the motor pathway to head and eye reflexes to sound leave the descending auditory pathway?
Inferior colliculus
At what point does the motor pathway to stapedius and tensor tympani leave the descending auditory pathway?
Superior olivary nucleus
At what point does the descending pathway to the cochlea leave the descending auditory pathway?
Cochlear nucleus
What is the function of the muscles in the inner ear?
Dampen loud noises to prevent damage to ear
Why is there a descending pathway to the cochlea?
Gives feedback to hair cells
Which cranial nerve provides the innervation to tensor tympani and stapes?
Trigeminal
