Visual System COPY Flashcards
The first 3 layers of the retina are the:
pigment epithelium, outer and inner segment layer, outer limiting membrane
The last 3 layers of the retina are the:
ganglion cell layer, nerve fiber layer, inner limiting membrane
limiting membranes are established by _________ joined at _______
glial cell processes, tight junctions
The _______ is adjacent to the pigment epithelium
choroid
The photoreceptor cell bodies reside in the _______ layer
outer nuclear layer
The photoreceptor cell processes exist in the __________
inner and outer segment layer
bipolar cells of the retina exist in the _______ layer
inner nuclear layer
Ganglion cells of the retina exist in the _________
ganglion cell layer
The ______ artery is fed by ciliary arteries
choroid
The sclera is deep to the ______
choroid
Rod photoreceptors are sensing light when cGMP levels are ______ and 5’GMP levels are ______
low, high
The ______ of a cone photoreceptor is the area of synapse
pedicle
The pedicle is a synaptic expansion of cone photoreceptors and includes the ________
synaptic ribbon
The L-cone and M-cone photoreceptor DNA is on the ________ chromosome, while the S-cone is on the _________ chromosome
X chromosome, autosome
Horizontal cells provide for lateral inhibition in ________ layer to _______ cells and ______ cells which sharpens images
outer plexiform layer, bipolar cells, photoreceptor cells
Amacrine cells provide lateral inhibition to ________ layer to _____ cells and ______ cells, which increases ganglion cell sensitivity to moving stimuli
inner plexiform layer, bipolar cells, ganglion cells
Typically photoreceptors synapse with __________ cells
both on-center and off-center bipolar cells
Each _______ cell synapse with an on-center ganglion cell
on-center bipolar cell
In _______, glutamate binds its receptor and an ion channel opens to cation entry when photoreceptors are activated
open channels of on and off-center cells
In _______ of on and off-center cells, glutamate binds its receptor and the associated ion channel closes to cation entry
closed channels
The ________ is located in mesoderm and induces ectoderm to differentiate into neuroectoderm, neural plate, neural groove, then neural tube
notochord
The ________ eventually forms the CNS
neural tube
The ________ after neurulation eventually forms the PNS
neural crest
Prior to cranial neuropore closure, two ________ form on either side of the forebrain
optic grooves
The _______ arises from ectoderm near the neural tube
neural crest
optic vesicles are __________ which form after cranial neuropore closure
outpocketings of the forebrain
The ________ induces formation of the lens placode from surface ectoderm
optic vesicles
The ________ forms a double-walled optic cup in week 5 of development with an inner (neural layer) and an outer (pigmented) layer
optic vesicle
In week 6 of development the ________ connects the optic cup to the forebrain and becomes the optic nerve
optic stalk
The sheath of the optic nerve is continuous with:
the meninges of the brain and the choroid and sclera
The ______ is the space between the pigment layer and neural layer of the retina during development
intraretinal space
The _______ lies at the most distal end of the iris
sphincter pupillae
The sclera, stroma of the cornea, ciliary body, iris, and choroid are derived from the ________ of the ________
neural crest, mesoderm
The _______ is derived partly from neural ectoderm of the optic cup, and partly from mesenchyme
vitreous body
The sphincter pupillae and dilator pupillae muscles are derived from ________
neural ectoderm
The lacrimal gland and its drainage system are derived from:
surface ectoderm
SHH is secreted by the _______ during development and inhibits PAX6 expression in midline and upregulates PAX2 expression in midline
prechordal plate
______ is master gene for eye development and regulates differentiation of optic cup and lens
PAX6
_____ regulates differentiation of the optic stalk and optic nerve
PAX2
________ may occur if the choroid fissure fails to close in the 7th week of development
coloboma (cleft optic cup/optic stalk)
_______ is the most common type of this disease and may affect structures more proximal
coloboma iridis (cleft of iris)
Mutations in _____ have been linked to optic nerve colobomas
PAX2
The lens of the eye is a ________ and images from it appear _______
convex lens, reversed and inverted
The ______ of the eye is continuous with dura mater
sclera
The ______ is composed of the iris, ciliary body, and choroid
uvea
The connecting stalk (cilium) of each photoreceptor is made from ________
9 pair microtubule cytoskeleton
The pigment epithelium has ______ which interdigitate with the outer segments of rod cells
apical processes of pigment epithelial cells
The ___________ functions to supply the neural retina with glucose and ions, maintain photoreceptor anatomy by phagocytosis
pigment epithelium
