Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
At which day and what form does the eye appear?
|
A pair of shallow grooves at day 22
|
|
|
From where do these optic grooves originate?
|
Dienchephalon
|
|
|
What structures doe these grooves come into contact with?
|
Surface ectoderm, lens formation
|
|
|
What happens when the groove and ectoderm meet?
|
Lens placode cells become columnar and invaginate
|
|
|
What are the two layers of the optic cup?
|
Pigmented layer
Nervous layer |
|
|
What changes happen to allow blood supply for the developing eye?
|
Groove on ventral surface that forms the choroid fissure
A branch of the opthalmic artery, hyaloid artery then passes through. |
|
|
What structures does the hyaloid artery support?
|
Developing lens and retina
|
|
|
What structure does both layers of the retina give rise to?
|
Ciliary body at the rim of the optic cup
|
|
|
What does the ciliary body secrete?
|
Aqueous humour
|
|
|
How does the lens form?
|
Cells elongate anteriorly to form long lens fibres, they arrange into a laminar pattern to form a transparent lens
|
|
|
What are they key weeks for Optic nerve formation and what happens in each one?
|
Week 6: Optic cup connects to brain by optic stalk. Hyaloid vessels in CF
Week 7: Inner and outer layer fuse, cavity of stalk disappears Week 9: Stalk becomes nerve, hyaloid becomes central a&v |
|
|
Eyeball development?
|
Mesenchyme forms layers of eyeball, choroid and cornea
Vitreous body forms - post chamber |
|
|
When do the formed eyelids separate in utero?
|
Between 5th and 7th month
|
|
|
Molecular regulation.
Key molecule? Expression? Eye field separation? |
Key molecule: Pax6
Expression: Ant. Neural plate pre-neurulation Eye field separation: Shh--> Inc Pax 2 in stalk and down pax 6 to optic cup and lens |
|
|
Eye abnormalities?
|
Cyclopia: Shh mutation
Anophtalmia: Absence of eye Microphtalmia: Small eye - IU disorder Congenital cataracts: Rubella, genetic causes |
