Auricle or Pinnae
the external portion of the ear
external acoustic meatus
ear canal
tympanic membrane
ear drum
ceruminous glands produces
ear wax- cerumen
the middle ear encloses and protects the
auditory ossicles
the auditory ossicles are
the malleus, incus, and stapes
the oval window is connected to the
stapes
tensor tympanic muscle
stiffens the malleus and tympanic membrane
stapedius muscle
reduces movement of the stapes on the oval window
the membranous labrynth contains
endolymph
endolymph is similar to
intracellular fluid
the endolymph has high levels of
potassium- 110
the sodium concentration in endolymph has very low levels of
sodium- 20
the bony labrynth is surrounded by
perilymph
perilymph is similar to
CSF
the vestibular complex gives us a sense of
equilibrium
the vestibule contains the
utricle and saccule
the utricle and saccule are for our sense of
gravity, linear acceleration
the semicircular canals give sense of
rotation
the cochlea gives sense of
hearing
receptor cells for hearing are located in the
cochlear duct
the cochlear duct has high levels of
potassium
the three chambers of the cochlea in order are
scala vestibuli, cochlear duct, scala tympani
the vestibular duct (scala vestibuli) recieves vibration from
the stapes and oval window
the scala vestibuli contains
perilymph
the scala tympani contains
endolymph
hair cells can be found in the
Organ of Corti located within the Cochlear duct
intensity of sound depends on
the number of hair cells activated and how much energy it contains
frequency depends on
cycles per second and which region is activated
the round window separates
the perilymph from the air spaces of the middle ear
hair cells are
basic receptors of the inner ear
hair cells contain
stereocilia
high pitch frequencies are found
at the base of the cochlea
low pitch frequencies are found
at the tip (apex) of the cochlea
sensory neurons for hearing are located in the
spiral ganglion (first order neurons)
the cochlear nucleus is a
second order neuron
the inferior colliculus of the mesencephalon is a
third order neuron
the thalamus is a
fourth order neuron
the inferior colliculus gives us reflexes that respond to
sound
when hair cells bend, they
depolarize
when hair cells straighten out
they stop depolarizing