Final: Eye Develoment Flashcards
Development of the preplacodal region involves activation of _____ pathway & inhibition of _____ & _____.
FGF.
Wnt & BMP
Arrange the following in order of least to highest concentration with increasing BMP concentration.
Neural plate
Placodes
Neural crest
Placodes, Neural crest, Neural plate
The optic stalk forms the _____.
Optic vesicle
The _____ artery uses the _____ _____ & _____ _____ to pass into the posterior chamber of the eye.
Hyaloid
Choroid fissure
Optic stalk
Absence of the Pax6 gene in mammals results in…?
Early optic vesicle formation, but not rest of eye
Absence of the Pax6 gene in mammals results in…?
Early optic vesicle formation, but not rest of eye
High concentrations of _____ inhibit Pax6 expression.
Shh
Shh is in high concentrations in the _____ (distal/proximal) part of the eye and induces expression of Pax2.
Proximal
T/F: Lens fiber cells are postmitotic.
True
_____ accumulate in the vitreous humor and stimulate formation of lens fibers.
FGF
What is the iris derived from?
Pigmented layer of retina
What is the term for absence of an eye resulting from a mutation in RAX, attributed to lack of formation of the optic vesicle?
Anophthalmos
What is the term for an eyeball that is slightly smaller or almost vestigial (compared to the normal one) and is associated with intrauterine infections & rubella syndrome?
Microphthalmos
What is the term for nonclosure of the choroid fissure of the iris during the 6th or 7th week of development?
Coloboma of the Iris