Auditory System Flashcards
What is the middle ear
Located w in temporal bone, filled w air that travels through auditory tube, begins just beyond tympanic membrane and ends at round window. Contains the stapes, incus, malleus. Functions to transfer acoustic energy from compression waves in air to fluid- membrane waves w in the cochlea.
What is the external ear and what role does it play in hearing?
Consists of pinna, helix, lobule concha, external auditory meatus. etc. it functions to amplify/collect signals and sounds- resonance
What structure separates the external ear from the middle ear
Tympanic membrane
What is the inner ear? Function?
Consists of a membranous labyrinth encased in osseous labyrinth: semicircle canals, vestibule, cochlea. Functions to detect sound and balance.
Name the cavity that contains the auditory neuroepithelium.
Membranous labyrinth
Membranous vs osseous labyrinth
Membranous- consists of a series of endolymph- filled ducts and chambers that lie within the osseous labyrinth. (Scala media)
Osseous- hollowed out region of the petrous portion of the temporal bone filled w a fluid called perilymph. (Scala vestibuli)
What is the scala vestibuli
Scala vestibuli is a perilymph-filled cavity inside the cochlea of the inner ear that conducts sound vibrations to the scala media. Contains reissners membrane
What is the scala media?
The cochlear duct (or scala media) is an endolymph filled cavity inside the cochlea, located in between the scala tympani and the scala vestibuli, separated by the basilar membrane and Reissner’s membrane (the vestibular membrane) respectively. Contains organ of corti and basilar membrane
What is the scala tympani
Scala tympani is one of the perilymph-filled cavities in the cochlear labyrinth. It is separated from the scala media by the basilar membrane, and it extends from the round window to the helicotrema. It functions to transduce the movement of air that causes the tympanic membrane and the ossicles to vibrate, to movement of liquid and the basilar membrane.
What is contained w in the cochlear duct ( scala media)?
Endolymph, Tectorial membrane, organ of corti, inner hair cells
What are cochlear nuclei
The cochlear nuclei are two heterogeneous collections of neurons in the brainstem that receive input from the cochlear nerve, that carries sound information from the cochleae. The outputs from the cochlear nuclei are received in higher regions of the auditory brainstem.
What is the lateral lamniscus
The lateral lemniscus is a tract of axons in the brainstem that carries information about sound from the cochlear nucleus to various brainstem nuclei and ultimately the contralateral inferior colliculus of the midbrain.
What is the inferior colliculus
The inferior colliculus is the principal midbrain nucleus of the auditory pathway and receives input from several peripheral brainstem nuclei in the auditory pathway, as well as inputs from the auditory cortex.
What is the medial geniculate body
Is part of the auditory thalamus and represents the thalamic relay between the inferior colliculus (IC) and the auditory cortex (AC).
What is the superior temporal gyrus
The superior temporal gyrus contains the primary auditory cortex, which is responsible for processing sounds. Some areas of the superior temporal gyrus are specialized for processing combinations of frequencies, and other areas are specialized for processing changes in amplitude or frequency.
