Embryology of the Eye

Question 1

what are the four sources responsible for development of the eye

Answer 1

neuroectoderm
surface ectoderm
mesoderm
neural cest cells

Question 2

neuroectoderm give rise to

Answer 2

retina and posterior layers of the iris and optic nerve

Question 3

surface ectoderm gives rise to

Answer 3

lens and corneal epithelium

Question 4

mesoderm gives rise to

Answer 4

fibrous and vascular coats of the eye

Question 5

neural crest cells give rise to

Answer 5

choroid, sclera, and corneal endothelium

Question 6

the optic vesicles grow out of the

Answer 6

forebrain

Question 7

the optic vesiicles elongate to form

Answer 7

optic stalks

Question 8

the cavity of the optic vesicles is continous with the

Answer 8

forebrain

Question 9

surface ectoderm forms

Answer 9

lens placodes

Question 10

the lens placodes will form________

Answer 10

lens pits which will invaginate to form lens vesicle

Question 11

the distal ends of the optic stalk will widen and

Answer 11

form optic cups and become associated with the lens vesicle

Question 12

what does the hyaloid artery supply

Answer 12

the developing lens

Question 13

the optic stalk becomes

Answer 13

optic nerve

Question 14

the hyaloid artery will become

Answer 14

central artery of the retina (a branch from the opthalmic artery)

Question 15

where does the retina develop from

Answer 15

walls of the optic cup

Question 16

the outer layer of the optic cup becomes

Answer 16

pigmented retina

Question 17

the inner layer of the optic cup becomes

Answer 17

neural (unpigmented) retina

Question 18

what are deepest in the retina

Answer 18

photoreceptor cells

Question 19

the ciliary body dervies from

Answer 19

choroid mesenchyme and both layers of the optic cup

Question 20

the ciliary process is from

Answer 20

outer and inner layer of the optic cup

Question 21

ciliary muscles are derived from

Answer 21

choroid mesenchyme at the anterior edge of the optic cup

Question 22

_____________forms from the front edge of the optic cup

Answer 22

iris

Question 23

edges of the optic cup grow together to form

Answer 23

pupil

Question 24

the lens is derived from

Answer 24

surface ectoderm

Question 25

what are the sources of the cornea

Answer 25

surface ectoderm, mesoderm, and neural crest cells

Question 26

mesenchyme that surrounds the optic cup develops into

Answer 26

choroid and sclera

Question 27

the conjunctival sac is

Answer 27

the space between the cornea and the eyelids (lined by ectoderm)

Question 28

the eyelids are composed of what

Answer 28

surface ectoderm with a core of mesenchyme (neural crest)

Question 29

orbicularis oculi is derived from

Answer 29

2nd pharngeal arch

Question 30

how do the lacrimal glands form

Answer 30

they form from invaginations of the ectoderm of the conjunctival sac

Question 31

the ________develops from a space between the lens and the corna

Answer 31

anterior chamber

Question 32

the _____________develops from a space that forms in the mesenchyme posterior to the iris and anterior to the lens

Answer 32

posterior chamber

Question 33

vitreous humor is derived from

Answer 33

neural crest mesenchyme

Question 34

the extrinsic eye muscles from from

Answer 34

preotic somites

Question 35

congenital retinal detachment

Answer 35

failure of the two layers of retina to fuse,

Question 36

coloboma

Answer 36

defect involved in improper closing of the choroid fissure in a gap in the iris or iris and retina

Question 37

cyclopia

Answer 37

occurs when there is a fusion in the midline

Question 38

synopathlamia

Answer 38

incompletely fusion of the eyes

Question 39

clyclopia

Answer 39

defect of the midline structures; incompatible with life

Question 40

micropthalmia

Answer 40

small normal appearing eye but may lack a lens

Question 41

anophthalmia

Answer 41

congenital absence of eye tissue

Question 42

persistent pupillary membrane

Answer 42

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

Question 43

congenital glaucoma

Answer 43

increase in intraocular pressure; defect in the slceral venous sinus

Question 44

congenital cataract

Answer 44

lens opacity present caused by rubella, chicken pox, herpes or geneitc

Question 45

anridia

Answer 45

absence of an iris; defect in neural crest

Question 46

color of irisis acquied

Answer 46

8-10 months

Question 47

congenital aphakia

Answer 47

absence of a lens

Question 48

congenital ptosis

Answer 48

levator palpebrae superioris or loss of innveration to the muscle

Question 49

retinoblastoma

Answer 49

neuronal tumor arising from the retina; the most common primary intraocular malignancy of childhood