Exam Three - vision Flashcards
pupil
controls the amount of light available
cornea
transmit and focuses light into the eye
iris
helps regulate the amount of light entering the eye
ciliary muscle
helps focus the lens
sclera
white outer coat of the eye
vitrous fluid
the clear, gelatinous substance filing the central cavity of the eye
lens
focuses light onto the retina
retina
senses light and creates electrical impulses
macula
area in the retina that contains special light sensitive cells
small area at the center of the retina
a thin layer of light-sensitive tissue that lines the back of the eye
fovea
center of the macula, central and sharpest vision
optic nerve
carry visual message from the retina to the brain
rods respond to
low light
cones respond to
different light wavelengths (color)
L cones
red
M cones
green
S cones
blue
parasol cell (M cell)
sensitive to low-contrast, black and white stimuli
Midget Ganglion cell (P cell)
sensitive to color
What is the direction of neural flow layers from outside to inside
pigment epithelium
outer layer (rods and cones)
outer plexiform layer
inner layer (horizontal, bipolar, and amacrine cells)
inner plexiform layer
ganglion cell layer (parasol and midget gang cells)
3 regions of photo receptors are:
outer segment
inner segment
region of synaptic terminals
rod cell is ________ in response to light stimulus
hyperpolarized
the hyperpolarization of rod cells causes a ____________ in release of glutamate which can depolarize some cells or hyperpolarize others
reduction
cones release ________ in the dark and respond to light by__________
glutamate, decreasing glutamate release
rods or cones have high concentration in the fovea
cones
rods or cones mediate color vision
cones
cones have high or low acuity of vision
high
loss of _____ causes night blindness and loss of peripheral vision
rods
rods or cones have high sensitivity to light
rods
rods or cones have a slow response to light stimulus
rods
rods or cones are specialized for day vision
cones
light falls onto photoreceptors in the ____
retina
_______ serves a strategic role in gating information flow to cortex
thalamus (LGN)
dorsal pathway is the ______ and ventral pathway is the ________
where, what
______ pathway is the primary visual cortex to posterior parietal cortex
dorsal
_________ pathway is the primary visual cortex to the inferotemporal xortex
ventral
emotion related visual processing has a connection with the _______ route
ventral
the ________ in the thalamus is the major target of the retinal ganglion cells
LGN
the ________ in the thalamus receives input from both eyes and relays these messages to the primary visual cortex via the optic radiation
LGN
The LGN projections reach the ___________ through the optic radiations
primary visual cortex
The _______ visual field sweeps around the lateral horn of the ventricle under the temporal lobe (meyers loop)
superior
The ________ visual field travels under the cortex of the parietal lobe
inferior
primary visual cortex is broadman
17
secondary visual cortex is broadman
18, 19
scotomas
small visual field deficit
anopsias
large visual field deficits
nonhomonymous anopsia
visual field deficit that affects opposite halves of both eyes
homonymous anopsia
visual field deficits that affect the same part of both eyes
miosis
excessive constriction of the pupil, can also be caused by drugs or illness
What is the pathway of the pupillary light reflex (constriction)
light on retina, pretectum and Edinger-Westphal, to ciliary ganglion, to pupillary sphincter muscle
What would happen to the pupillary reflex if you shine light into the right eye and there is a right optic nerve lesion?
neither pupil will constrict
What would happen to the pupillary reflex if you shine light into the right eye and there is a left optic nerve lesion?
both pupils will constrict
the accommodation reflex involves these 3 events
- convergence of the eyes
- constriction of the pupil
- suspensory lig relaxes
myopia
nearsighted
if you are nearsighted then you have a _______ lens
concave
hypermetropia
farsighted
if you are farsighted, then you have a __ lens
convex
glaucoma
condition that causes damage to they eyes optic nerve and gets worse over time
people with diabetes are twice as likely to develop it
cataract is
the clouding of the lense
cataracts are related to
aging
diabetes
smoking and alcohol use
prolonged exposure to sunlight or bluelight
prosopagnosia
face blindness
people with prosopagnosia have ________ vision
normal
prosopagnosia is associated with a brain injury in the __________–
right fusiform gyrus
Adie’s pupil is
a prolonged and sluggish contraction of the pupil to light
following the pupillary constriction, the dilation is then delayed
adie’s pupil is associated with pathological changes in the…
ciliary ganglion
macular degeneration is…
a progressive loss of vision
most common in those older than 55
