Eye Flashcards
Corneal stroma/endothelium
Choroid and sclera (w/meso)
iris stroma
connective tissue of extra ocular muscles
ciliary muscle are from…
Neural crest cells of the head mesenchyme
Optic nerve, retina, Iris muscles, RPE, vitreous humor
derive from
Neuroectoderm
Lens cornea conjunctiva/caruncle eyelid lacrimal gland and drainage are from..
suface ectoderm
Week eye development begins
week 4
optic pits
inward bulges of ectoderm on either side of neural tube
optic vesicle
increase in cell proliferation leads to large spherical bilge connected to neural tube by a thin optic stalk (all still ectoderm) (~25days)
What induces formation of the lens/ derived from?
optic vesicle, made from ectoderm. Lens placode develops here (starts as lens vesicle and then is filled in with cells) (lens=ectoderm)
When an eye is formed with no lens, what else may be present?
Microopthalmia or anophthamia
Optic cup
Invagination of lens placode, asymmetric with a deep groove on inf. surface (choroid fissure)
Artery that runs through the choroid fissure on the inferior aspect of the optic cup
Hyaloid artery (embryonic structure), but will become the central retinal artery
What cell types fill up the lens vesicle?
anterior lens cells- cuboidal, single layer
posterior lens cells- multiply and elongate
outermost cells- lens capsule
*newer (secondary) fibers are laid over pre-existing (primary), therefore the oldest cell fibers in center and newest at equator
**first ocular structure to show cellular differentiation
35% of the protein in the lens
cristallin
Precursors of retina, optic nerve, lens, and cornea are present by what week?
week 6 (develops from inside to out)
Incomplete closure of choroidal fissure creates…
Colobomas- incomplete, improperly formed, or depigmented segments in iris, lens, choroid, retina, ciliary body (can be associate w/ microopthalmia)
What is the first retina layer to differentiate?
Retinal pigment epithelium. week 3-4
@ week 6- RPE is one cell thick
Major events of week 4
Eye development , including RPE
Major events of week 5
Lens development begins and Choroid fissure begins to close . corneal differential complete
Major events of week 7
Choroid fissure is closed, and 2 layer of optic cup are formed (outer- RPE, NPE of ciliary body, ant. iris/ Inner- neural retina, inner NPE of cb, post. iris)
sclera and choroid(w/NC) vitreous humor blood vessels extra ocular muscles pia, arachnoid, and dura of optic nerve
Mesoderm of head mesenchyme
Congenital cataracts cause
Rubella, lens is opaque or white
Optic stalk
Connects the forebrain and the optic vesicle, will become the optic nerve
Week 8
ganglion and amacrine cells
Week 12
phtotreceoptors and synapses
6 months
cell density in the macula, dural layers around optic nerve (5-7 mo)
How do neural crest cells migrate in to form the cornea?
33 days- Between the surface ectoderm and lens vesicle
first wave- endothelium
Week 8- Between developing end and ectotheilium
second wave- stroma and pupillary membrane
- splits into ant and post
Anterior- stroma and endothelium of cornea
Posterior- Stroma of the iris
Sclera formation?
Condensation of the mesenchyme around the optic cup, Anterior first (week 5) Muscles attach by week 12
Ciliary body formation?
formed by neural crest cells by month 3
Ciliary epithelium produces zonular fibers
What is the Hyaloid system?
the hyaloid artery, mesenchyme derived, degenerates by 3-4 months. This artery produces a network that feeds the developing lens, through the tunica vaculosa lentis.
What are the derivatives of the ventral and dorsal ophthalmic arteries in the adult?
ventral o.- medial long posterior ciliary artery
dorsal o. - temporal long posterior ciliary and the short posterior ciliary
What are the upper and lower lids developed from?
Upper- frontonasal process
Lower- Maxillary process
