Lecture 8: Vision Flashcards
Where is the 3rd-order neuron located along the visual pathway?
Lateral geniculate nucleus of the Thalamus
Label the eye
Glaucoma is basically ________ in the eyeball
hydrocephalus
With glaucoma, the __________ __________ ________ is blocked
aqueous humor drainage
What part of the eye is divided into 2 chambers?
lens
The aqueous humor is like what? and drains into where?
CSF
anterior chamber
Vitreous humor (glass-like): filled by what?
blood vessels
What is this structure?
Focusing: is the ________ of __________
refraction; light
What two parts of the eye control refraction of light?
lens and cornea
The retina controls _______ and _______
brightness; quality
The ________ controls how much light gets in and will constrict to help our eyes adjust to light
iris
Label these parts of the eye
Cornea: ______ anteriorly, ______ adjustment
(transparent)
convex; gross
Lens: ________, ______ adjustment
( anterior convexity __________ )
biconvex; fine
adjustable
Cataract involves the _______ of the ______
opacity
lens
Ciliary muscle contraction: ___________ anterior convexity
- for ______ adjustment
- this muscle helps us see ______ ______
increases
fine
up close
Ciliary muscle relaxation: _______ anterior convexity and is controlled by CN ____
decreases
III
What are these two structures?
Which eye muscle helps us see in the dark?
Pupillary dilator/dilator pupillae
Pupillary dilator/dilator pupillae is sympathetic: __________ ________ __________
superior cervical ganglia
Pupil: _______ effects
pinhole
_______: absorption of strayed light
Retina
Which eye muscle helps us adjust if the light is too strong?
Pupillary sphincter/Constrictor pupillae
The Pupillary sphincter/Constrictor pupillae involves CN III (Vm): ______ ganglion
ciliary
Label this
What is the pathology inducted by the MRI scan?
Hyrdocephalus
lateral and 3rd ventricles enlarged
crebral aqueduct compromised
Photoreceptors: not ______- detect diff wavelengths of light
Rods: _____ and ______
Cones, _____, _______, _______
neurons
black, white
blue, green, red
With structure of the retina, _______ __________ of the light goes into the eye, and _________ of the light comes out
projection direction
processing
Bipolar neurons: _____-______ neurons
Rods: bipolar= ___-_____: 1, _____ image
Cones:bipolar = __:__, _______
1st order
15; 30, gross
1, 1, acuity
With rods (black and white), you cannot see _______ only ______
details, shape
The _______ is the center of the macula
and is ______mm diameter
fovea
1.5
The _______ is deep to the fovea and is ____ mm diameter
foveola
0.15
The foveola is associated with which bipolar neurons and for what purpose?
cones, for visual acuity
_________ is when. you fix the fovea on target objects
foveation
The macula is ______ to the _______ ______
which is ____ mm diameter
lateral; optic disk
5.5
With legally blind people, what is going on?
The macula has degenerated and cannot see details
Our blind spot = ?
no photoreceptors
Visual Pathway to V1
_________ ________: the brain’s ability to simultaneous process different aspects of a visual scene, color, shape, motion, etc by sending info through separate neural pathways allowing for a quick comprehensive understanding of what is being viewed
parallel processing
Geniculostriate Pathway
Lateral _________ ________ to V1
geniculate nucleus
Geniculostriate Pathway
__________ projection fibers: parietal lobe
_________ quadrant
Superior
Inferior
Geniculostriate Pathway
_________ projection fibers: temporal lobe, Meyer’s loop
_________ quadrant
Inferior
Superior
Macula projecting 60% of _______ ________
posterior V1
__________: spatial information conserved
* don’t need to look at the object to know what you’re doing
Retinotopy
How is the iris controlled by visceral motors when the sunlight is too strong?
Sphincter pupillae activated by CN III, decrease light into the eyeball
_________ __________: 2 symmetrical halves of the visual field
Visual hemi fields
________ hemifield: the nasal retina of the right eye and temporal retina of the left
Left
________ hemifield: the temporal retina of the right eye and nasal retina of the left
Right
Retina and Visual Fields
Optic nerve: _______ of the eye
_________ nasal and temporal retina
vision
ipsilateral
Optic chiasm: decussation of _________ nasal retina tracts
bilateral
Optic tract: vision of ________ _______ hemi fields
Ipsilateral _________ and contralateral ______ retina
both visual
temporal
nasal
Common visual impairments
- Blindness in the eye CN II
- Tunnel view: optic chiasm
- Homonymous Hemianopia: optic tract
- Superior quadrantopia: Myer’s Loop
- Homonymous Hemianopia: geniculostriate pathway
With blindness in the eyes, you will lose what?
bilateral nasal components
With tunnel view, there are usually _______ _______ _______ present
pituitary gland tumors
With Homonymous Hemianopia: optic tract, the patient cannot see what?
contralateral field
With Superior quadrantopia: Myer’s Loop, there is ________ _______ vision loss
superior quadrant
With Homonymous Hemianopia: geniculostriate pathway, there is damage to the ______ _______
lateral geniculate
The parallel projection pathways are not through the _________
thalamus
Parallel projection pathways
Tectopulvinar pathway is in the ( __________ )
- _________ area and _______ colliculus
- _______ ________ reflex
- ___________ association areas: _______ stream
midbrain
Pretectal, superior
pupillary light
visual; dorsal
________/_________ _________; a person can still unconciously perceive some visual stimuli, like the movement of a simple object, despite being unable to see anything
Blindsight/Riddoch’s phenomena
Parallel projection pathways
Hypothalamus: ___________ nuclei
this is the relay for _______ ________
suprachiasmatic
circadian rhythm
Pupillary light reflex
Afferent : CN _____, specific ______ cells, no __________
- To the bilateral CN III _________ nucleus
II
ganglion
photoreceptors
parasympathetic
Pupillary light reflex
Efferent: CN _____, ________ of the bilateral pupils
III
constriction
Pupillary Light Reflex
Axon bundles from which side of the nasal and temporal retina are in the left optic nerve, chiasm, and right optic tract?
Left optic nerve: both Lnasal and temporal retina
Optic chiasm: bilateral nasal retina ganglion axons
Right optic tract: R temporal and L nasal retina ganglion axons
Which side CN II or CN III is compromised according to the the pupillary light reflex?
L eye II/ III normal
R III normal, R CN II compromised
