Neuro (04.01) Olfactory & Visual Systems Flashcards
olfaction is the senses of ___ and ___ via chemical sensation
- taste
- smell
olfaction detects ____ ____ (odorants) drawn into the nasal cavity
volatile chemicals
how many odors can humans detect?
10,000
the olfactory epithelium is the ____ origin of the olfactory system and is a patch in the roof of the ___ ___ and is ____
- peripheral
- nasal cavity
- bilateral
an olfactory receptor is a ____ neuron
bipolar
what is the life span of olfactory receptors?
1-2 months
concerning olfactory receptors, the dendrite ends in ____ ____, from which 10-30 ____ spread over the surface in a layer of mucus secreted by ____ glands
- olfactory vesicle
- cilia
- bowman’s
the olfactory receptors stimulate _____ cilia
chemosensitive cilia
axons from the olfactory receptors are among the ___ and ____
- thinnest
- slowest
the axons from olfactory receptors collect into a series of bundles called ____ ____ that pass through holes in the ____ ___ of the ethmoid bone
- olfactory fila
- cribiform plate
olfactory receptors end in the _____ ____
olfactory bulb
olfactory fill make up ____ ____
CN I
the olfactory bulb develops as an outgrowth of the _____
telencephalon
the olfactory bulb reaches the ____ hemisphere with ___ ___ in thalamus
- ipsilateral
- no relay
what re the two interneurons of the olfactory bulb?
- tufted cells (T)
- granule cells (G)
concerning mitral cells, axons collect join ___ ___ and the dendrites form ____
- olfactory tract
- glomeruli
olfactory fibers are sorted in the ___
bulb
each type of olfactory receptor sends an an axon to one ____ of a ____ ___ even though these cells are intermingled in the ____ ____
- glomerulus
- mitral cell
- olfactory epithelium
the olfactory fibers project to both bulbs by crossing in the ____ ____
anterior commisure
what are the two general areas that olfactory bulbs project?
- primary olfactory cortex
- amygdala
olfactory information is sent to what 5 places?
- hypothalamus
- thalamus
- hippocampus
- orbital cortex
- amygdala
direct projections of olfactory information are sent via ____ ___ ___
olfactory association cortex
the olfactory association cortex consists of what?
- orbital surface of frontal lobe
- anterior insula
what two things focus the image on retina?
- cornea
- lens
how much of the eye’s refractive power does the lens account for?
1/3
*major role in addicting focus for near/far objects
most refraction takes place at ___-___ interface at ___ surface
- air-water
- corneal surface
affects the brightness and quality of image focused on retina
iris
two mm in IRIS that control pupil size
- pupillary sphincter
- pupillary dialator
which m in the iris is the strongest?
pupillary sphincter
a ___ pupil improves ocular performace
smaller
*like small aperture size improves camera lens performance
the retina is composed of ____
photo receptors
the retinal structure consists of 2 interdeposed layer. what do both do?
- one cell type brings visual info in the other sends it out
- another type interconnects laterally
the ____ segment of rods and cones contains visual proteins
outer segment
type of photoreceptor used in the low-acuity, monochromatic vision in dim-light
rods (rhodopsin)
typer of photoreceptor used in high-acuity, color vision, and needs a lot of light
cones (cone pigments)
the ____ absorbed by rods and cones are what cause the receptor potential
photons
concerning rods and cones, visual pigment is synthesized and transported up the ___ ___ and incorporated into ___ ___
- ciliary stalk
- disc membranes
concerning rods and cones, older disks at the end are phagocytosed by ____ ___
pigment epithelium
defects of rods and cones cause some types of ___ ___
retinal degeneration
where nerve fiber layer converges and forms the optic nerve
optic disc
the ____ ___ of the brain fills in the blind spot formed by out ___ ___
- blind spot
- optic disc
center of the macula
fovea
the center of the fovea contains elongated ___ and no ___
- cones
- rods
the fovea is directly in line with the ___ ___
visual axis
where is visual information sent in the thalamus?
lateral geniculate nucleus
the lateral geniculate nucleus projects to what?
primary visual cortex
fibers representing inferior visual fields are most ___ in radiations and vice versa
superior
optic radiation behind lenticular nucleus that represents the SUPERIOR visual field
retrolenticular
optic radiation beneath the lenticular nucleus that represents the INFERIOR visual field
sublenticular
the ability of depth perception is accomplished by comparing areas of the ____ which is done by the ____
- retina
- chiasm
regarding lateral geniculate nucleus structure, numbers ___, ___, and ____ represent the CONTRALATERAL EYE
1
4
6
regarding lateral geniculate nucleus structure, numbers ___, ___, and ____ represent the IPSILATERAL EYE
2
3
5
regarding lateral geniculate nucleus structure, numbers 3-6 are _____ layers and deal with ___ and ___
- parvocelluar layers
- color
- form
regarding lateral geniculate nucleus structure, numbers 1-2 are ____ layers and deal with ___ and ____
- magnocellular layers
- movement
- contrast
famous doctor who described retinotopic organization of primary visual cortex
Dr. Tatsuji
optic radiations end retinotopically in the ____ ___ both above and below the ___ ___
- occipital cortex
- calcarine sulcus
___ visual fields are located ABOVE the calcimine sulcus
inferior
____ visual fields are located BELOW the calcarine sulcus
superior
thin stripe of myelin in primary visual cortex
line of gennari
___ ___ parallels calcarine sulcus and extends a bit to POSTERIOR suface
striate cortex
denotes loss of one or more quadrants of visual field
anopia (anopsia)
loss of half a visual field
hemianopia
loss of one quarter of a visual field
quadrantoanopia
same visual field lost in each eye
homonymous
tow eyes have non-overlapping visual field loss
heteronymous
type of herteronymous that is identical
congruous
type of heteronymous that is overlapping but not the same
noncongruous
damage anterior to chasm only affects the ____ eye
ipsilateral
damage at chiasm causes ___ ____
heteronymous deficits
damage to optic tract cause ____ ___
homonymous deficits
temporal lobe lesions can interrupt ___ ___ which represents inferior retinal quadrants
meyer’s loop
posterior cerebral artery infarction often results in deficit with sparing of ____
macula
regarding the pupillary light reflex, how would a lesion in the optic nerve affect the reflex?
both eyes with not constrict
regarding the pupillary light reflex, how would a lesion in the optic radiations affect the reflex?
it wouldn’t (it is a reflex so the light does not go that far posterior)
regarding the pupillary light reflex, how would a lesion in the visual cortex affect the reflex
nothing ( the reflex does not reach the cortex)
what are the 3 supplemental destinations of visual information?
- superior colliculi
- hypothalamus
- suprachiamatic nucleus (circadian rhythm)
responsible for breaking down visual info into component parts such as orientation, color, depth, motion, brightness
primary visual cortex
the primary visual cortex distributes visual info to specialized parts of ___ cortex
extrastriate
the visual cortex has a ___ organization
columnar
the ___ ___ has an array of repeated, modular collections of neurons arranged in columns
striate cortex
modules in foveal part analyze small areas of visual field, so fovea has many more modules and therefore ___ ___
better resolution
the ___ stream contains parvocellular layers (color)
ventral
the ___ stream contains magnocellular layers (location, movement
dorsal
