Ear (senses) Flashcards
Ear
responsible for hearing and equilibrium
Auricle/pinna
outer visible portion of the ear, channels sound waves into the auditory canal
External acoustic meatus/auditory canal
pathway directing sound towards the middle ear
Tympanic membrane
sound waves cause it to vibrate, boundary between external and middle ear
Middle ear
small air-filled cavity within the petrous portion of temporal bone, deep to the tympanic membrane
Ear ossicles
tiny bones that bridge the tympanic membrane to the oval window on the cochlea of the inner ear
Malleus/hammer
most lateral ossicle, attached to tympanic membrane
Incus/anvil
middle ossicle
Stapes/stirrup
most medial ossicle, attached to the oval window
Oval window
opening between middle and inner ear
Eustachian tube (pharyngotympanic)
connects middle ear and superior portion of the throat (nasopharynx)
- equalizes pressure in the middle ear
- opens when swallowing or yawning
Inner ear
bony labyrinth filled with perilymph fluid, contains a membranous labyrinth filled with endolymph fluid
Cochlea
spirals around a central axis and is divided into three ducts…vestibular duct, tympanic duct, and cochlear duct
Vestibular duct
begins at the oval window
Tympanic duct
ends at the round window
Cochlear duct (middle)
part of the membranous labyrinth filled with endolymph and contains the organ of corti
Organ of corti
contains auditory hair cell receptors responsible for hearing that extend between the flexible basilar membrane and the rigid tectorial membrane
Vestibule
central cavity of the bony labyrinth
- responsible for equilibrium (vestibular) sense-position of the head, detects linear and angular acceleration
- important for reflexes that maintain posture and move the eyes to stabilize an image as the head moves
Maculae
regions of the utricle and saccule that contain the hair cell receptors that detect linear acceleration
Semicircular canals
three canals orientated in one of the three planes contain semicircular ducts of the membranous labyrinth
Crista ampullaris
regions of the semicircular ducts that contain hair cell receptors that detect angular acceleration
Describe the auditory pathway from auditory hair cell receptors to primary auditory cortex
hair cell receptors>vestibulocochlear nerve (CNVIII)>medulla oblongata>Thalamus>Temporal lobe
Hair cell receptors
in the cochlea, release neurotransmitters onto the dendrites of bipolar neurons that have their soma in the spiral ganglion of the cochlea
