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Eye Development
Medical School Devo
51
Other
Graduate
09/29/2011

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Cards

Term
What are the three layers of the adult eye? What are they composed of?
Definition
Fibrous Layer: Sclera, and cornea

Vascular Layer: choroid, cilliary body, iris

Neural layer: retine
Term
What are the three spaces of the eye?
Definition
Anterior chamber
Posterior chamber
Vitreous body
Term
What are the borders of the anterior layer?
Definition
cornea and iris
Term
What are the borders of the posterior chamber?
Definition
iris and lens
Term
What are the borders of the vitreous body?
Definition
posterior to lens
Term
What are the sulci that initially form in the neural folds during eye development?
Definition
Optic grooves
Term
Optic grooves elongate to form what?
Definition
Optic vesicles
Term
As the optic vesicles grow, their distals end form what?
Definition
The optic stalk
Term
Surface ectoderm above the optic vesicle thicken to form what?
Definition
Lens placode
Term
How does the lens vesicle form?
Definition
lens placode invaginates and pinches off
Term
What is the optic cup?
Definition
optic vesicle invaginates and forms the goblet shaped optic cup which recieves the lens vesicle
Term
What is the choroidal (retinal) fissure?
Definition
fissure on ventral surface of optic cups that allows for vascular mesenchyme (hyaloid vessels) to enter. Fissure then closes and entraps the vessels
Term
What do the hyaloid vessels vascularize?
Definition
initally lens and posterior portion of the retina
Term
The hyaloid artery undergoes apoptosis and stops vascularizing what?
Definition
The lens (now recieves nutrients by diffusion from vitreous humor). Contnues providing vascularization to the retina
Term
Where does the retina develop from?
Definition
The wall of the optic cup. Inner layer proliferates to form a thick neuroepithelium
Term
Where does the signalling for the retina come from?
Definition
Developing lens
Term
How does the optic stalk become the optic nerve?
Definition
Axons of ganglia from the retina are sent into the stalk
Term
Where are the rods and cones located?
Definition
deepest layer of the retina, light has to traverse the retina
Term
What does the outer layer of the optic cup form?
Definition
retinal pigment epithelium
Term
What seperates the neuroectoderm and pigment retina from each other?
Definition
intraretinal space
Term
What is the clinical significance of the intraretinal space?
Definition
Site for retinal detachment because the two layers are not fused. Detachment will lead to blindness because the vascularization to the retina is on the pigment epithelium
Term
From what does the lens develop?
Definition
Ectodermal placode
Term
Posterior cells of the lens form into what?
Definition
Primary lens fibers. these fibers are post-mitotic
Term
Anterior cells of the lens form into what?
Definition
Secondary lens fibers. These cells continue to replicate
Term
What signalling molecule is involved in secondary lens formation?
Definition
FGF
Term
What part of the orbit signals the secondary lens fibers?
Definition
Retina
Term
The cornea is derived from what cells?
Definition
mesenchyme that fills space between lens and ectoderm
Term
What signals the development of the choroid and sclera?
Definition
retinal pigment epithelium
Term
What is the choroid and sclera derived from?
Definition
Mesenchyme
Term
What is the cilliary body?
Definition
Wedge shaped extension of the choroid, this is where cilliary muscle of accommodation forms
Term
Cilliary smooth muscle is derived from what?
Definition
Neural Crest cells
Term
The stroma of the iris is derived from what?
Definition
neural crest cells
Term
The dilator pupilae and sphincter pupillae are derived from what?
Definition
Neuroectoderm
Term
What the critical factor involved with iris color?
Definition
Melanin concentration
Term
What is the pupillary membrane?
Definition
Transient structure that separates the anterior and posterior chamber
Term
Where does the vitrous body form?
Definition
In the cavity of the optic cup
Term
What is vitreous body derived from?
Definition
mesenchyme
Term
What is the vitreous humor made by?
Definition
Neural crest cells
Term
What is the vitreous humor derived from?
Definition
Mesenchymal cells
Term
What do lacrimal glands develop from?
Definition
Solid buds of surface ectoderm
Term
Eyelashes and glands of eyelids are derived from what?
Definition
Surface ectoderm
Term
What do eyelids develop from?
Definition
neural crest mesenchyme and folds of ectoderm that grow over cornea
Term
What is microophthalmos?
Definition
Small eyes
Term
What is coloboma of the iris?
Definition
"Keyhole iris". Defective closure of retinal fissure.
Term
What is cyclopia?
Definition
Single median eye
Term
What is Anopthalmia?
Definition
Absence of all tissues of the eye
Term
What is congenital aniridia?
Definition
Absence of iris
Term
What is Congenital Aphakia?
Definition
absence of the lens
Term
What is ptosis?
Definition
Drooping of eyelid
Term
What is the impact of increased CSF pressure on the eye?
Definition
Edema of the optic disc which will slow venous return from retina. Can detect venous swelling here (called papilladema), clinically very useful
Term
What are eye defects associated with Rubella (measles)?
Definition
Congenital glacoma and cataracts
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