Embryo Development Flashcards
What develops in weeks 3-4
eye fields and optic vesicle; takes
what develops in weeks 5-6
optic cup, lens vesicle, choroid fissure and hyaloid artery
what develops in weeks 7-8
“CARL”
cornea, anterior chamber, retina, and lens
what develops in weeks 8-10
eyelids
what develops in weeks 9-15
iris and ciliary body
eye fields develop from population of cells from inter _____ ____
neural plate
Eye fields start off in _____ of brain
prosencephalon
Optic grooves become the optic ____
stalk
eye fields become optic _____ which are connected by optic _____ which become the optic stalk
vesicles; grooves
Lens placode develops into lens vesicle & pinches off to surface -___
ectoderm
The two layers of the optic cup become ___ and pigmented layers of the retina
neural
the optic stalk forms the ______ fissure
choroid
Within fissure, the _____ artery grows and develops what is going to feed the dev in the eye.
hyaloid
what is the purpose of irido pupillary membranes
serves as the scaffolding for creating the iris; they persist up to birth
the lens placode becomes the lens ____, the optic vesicle becomes the optic _____
vesicle, cup
where does the outer epithelial layer come from?
neural/surface ectoderm
Where does the inner layer come from
neural crest cells
Which type of cells are migratory
neural crest cells
The eyelid remains closed up until the _____ trimester
third
The iris forms from the optic _____
cup
What are the 2 pathways of the retina
- making ganglion and amacrine cells
- Making cones and horizontal cells
- Both groups can form rods and bp cells
which cells are made before birth
ganglion and horizontal cells
which cells are the initial differentiation cells
amacrine, cones, GC and horizontal cells
which cells are made after birth
amacrine, rods, muller, and bipolar cells
An optic ____ is usually the first thing we see
nerve
Which cells serve as scaffolding for other cells to latch on?
Radioglial cells
Which layer becomes one of the first specified layers?
ganglion cell layer
what is a special type of synapse that doesn’t occur anywhere else in the nervous system
ribbon synpase; bp cells make synaptic junctions with PR
which cells make synapses first
cones and horizontal cells
how does the sequencing of synapses occur?
Always horizontal cells with cone/rod first then cone/rod to bipolar cells next.
Our glutamate receptors appear to ___ bp cells so our first response is excitatory, which is in the dark
off
Our amacrine cells start off with strong _____ response
on
Which animal starts off with anisotropic gc receptive field but then becomes isotropic when exposed to light?
turtle
What is necessary to facilitate the age-related loss of on-off GC with maturation
light stimulation
Whats the difference between monocular deprivation in birth vs as an adult?
At birth: All dominance columns shift to the open/non sutured eye
As adult: The number of cells in covered eye decreases…the cortical activity is reduced. (after critical period)
What is the critical period for cats?
First 12 weeks of life (3 months)
Explain reverse suturing
If you suture right eye of cat during critical period and then unsuture right eye and then suture left eye, the right eye would have opportunity to generate own ocular dominance column and get some binocular function back.
What happened when they studied monkeys during binocular deprivation in complete darkness
deterioation of visual cortex, atrophy of cortical regions, remained blind for the rest of their lives.
Only the ____ cells return to their normal size. Magno cells don’t respond as well.
parvo
T/F Binocular activation had a significant benefit
F; leaving both eyes open resulted in permanent amblyopia
