Ch 6 &7 Flashcards
photoreceptor
biological sensors of light including rod & cone photoreceptors
sensory transduction
process by which an external stimulus is converted into a change in electrical activity of sensory neurons or other sensory cells
rod photoreceptors
unusual neurons that fire no APs, w unusually short axon & possess, instead of dendrites, rod shaped outer segment, located in periphery of retina, sensitive to dim light
cone photoreceptors
2nd type of photoreceptor w cone shaped outer segment, mainly in fovea (center of retina), less sensitive to light
blind spot
location of visual field where you can’t detect visual stimuli (while looking through one eye) bc corresponding location on retina (optic nerve head) lacks photoreceptors
macula
lateral to the blindspot, a roughly circular, more darkly pigmented region of retina devoid of underlying blood vessels, contains fovea
fovea
small region of retina that (in humans) contains very high density of cones & very few rods
rhodopsin
photosensitive pigment in rods
optic nerve head
location where axons of retinal ganglion cells cross thru retina to exit eye & enter optic nerve, creates blind spot
retina
multilayered neural structure at back of eye contains photoreceptors, retinal interneurons, & neurons that project thru optic nerve to brain
olfactory bulb
most rostral part of telencephalon in most vertebrates, located on inferior surface of frontal lobe in humans; receives inputs from olfactory epithelium & projects olfactory cortex
olfactory epithelium
layer of cells in roof of nasal cavity that houses olfactory sensory neurons
olfactory sensory neuron
neurons in olfactory epithelium that express olfactory receptor molecules & project olfactory bulb
tympanic membrane
thin membrane separating ear canal from middle ear, known as eardrum, vibrates in response to airborne sounds
malleus
one of middle ear bones attached to tympanic membrane
incus
one of middle ear bones; connects malleus to stapes
stapes
one of middle ear bones; attaches to oval window
oval window
thin membrane covering entrance of cochlea
round window
thin membrane covering basal end of scala tympana; always vibrates together with oval window but in opposite direction
cochlea
spiraling, tubular part of inner ear responsible for sensing sounds
scala vestibuli
half of cochlear tube that extends from oval window to top (apex) of cochlea
scala media
fluid filled compartment in cochlea , between scala vestibuli & scala tympani
scala tympani
half of cochlear tube that extends from top (apex) of cochlea to round window
tectorial membrane
relatively thick membrane that lies on top of hair cells of basilar membrane
stereocilia
“hairs” of hair cells, actually microvilli, rather than cilia
hair cell
sensory cells that sit on top of the basilar membrane of the cochlea & extend stereocilia into the scala media or, in the case of the outer hair cells, the tectorial membrane; thy are also found in the vestibule and semicircular canals
inner hair cell
the hair cells closest to the center of the spiraling cochlea; they sense vibrations of the basilar membrane