Embryology of the Eye Flashcards
what are the four sources responsible for development of the eye
neuroectoderm
surface ectoderm
mesoderm
neural cest cells
neuroectoderm give rise to
retina and posterior layers of the iris and optic nerve
surface ectoderm gives rise to
lens and corneal epithelium
mesoderm gives rise to
fibrous and vascular coats of the eye
neural crest cells give rise to
choroid, sclera, and corneal endothelium
the optic vesicles grow out of the
forebrain
the optic vesiicles elongate to form
optic stalks
the cavity of the optic vesicles is continous with the
forebrain
surface ectoderm forms
lens placodes
the lens placodes will form________
lens pits which will invaginate to form lens vesicle
the distal ends of the optic stalk will widen and
form optic cups and become associated with the lens vesicle
what does the hyaloid artery supply
the developing lens
the optic stalk becomes
optic nerve
the hyaloid artery will become
central artery of the retina (a branch from the opthalmic artery)
where does the retina develop from
walls of the optic cup
the outer layer of the optic cup becomes
pigmented retina
the inner layer of the optic cup becomes
neural (unpigmented) retina
what are deepest in the retina
photoreceptor cells
the ciliary body dervies from
choroid mesenchyme and both layers of the optic cup
the ciliary process is from
outer and inner layer of the optic cup
ciliary muscles are derived from
choroid mesenchyme at the anterior edge of the optic cup
_____________forms from the front edge of the optic cup
iris
edges of the optic cup grow together to form
pupil
the lens is derived from
surface ectoderm
what are the sources of the cornea
surface ectoderm, mesoderm, and neural crest cells
mesenchyme that surrounds the optic cup develops into
choroid and sclera
the conjunctival sac is
the space between the cornea and the eyelids (lined by ectoderm)
the eyelids are composed of what
surface ectoderm with a core of mesenchyme (neural crest)
orbicularis oculi is derived from
2nd pharngeal arch
how do the lacrimal glands form
they form from invaginations of the ectoderm of the conjunctival sac
the ________develops from a space between the lens and the corna
anterior chamber
the _____________develops from a space that forms in the mesenchyme posterior to the iris and anterior to the lens
posterior chamber
vitreous humor is derived from
neural crest mesenchyme
the extrinsic eye muscles from from
preotic somites
congenital retinal detachment
failure of the two layers of retina to fuse,
coloboma
defect involved in improper closing of the choroid fissure in a gap in the iris or iris and retina
cyclopia
occurs when there is a fusion in the midline
synopathlamia
incompletely fusion of the eyes
clyclopia
defect of the midline structures; incompatible with life
micropthalmia
small normal appearing eye but may lack a lens
anophthalmia
congenital absence of eye tissue
persistent pupillary membrane
normally covers the anterior surface of the lens and disappears during developemnt; remains as strands of CT tissue spanning the pupil but will rarely interfere with vision
congenital glaucoma
increase in intraocular pressure; defect in the slceral venous sinus
congenital cataract
lens opacity present caused by rubella, chicken pox, herpes or geneitc
anridia
absence of an iris; defect in neural crest
color of irisis acquied
8-10 months
congenital aphakia
absence of a lens
congenital ptosis
levator palpebrae superioris or loss of innveration to the muscle
retinoblastoma
neuronal tumor arising from the retina; the most common primary intraocular malignancy of childhood
