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12 Cards in this Set
- Front
- Back
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What are the 3 germ cell layers?
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Ectoderm
Mesoderm Endoderm (Neural crest) |
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What structures are derived from surface ectoderm?
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Corneal epithelium
Conjunctival epithelium Lacrimal gland Tarsal glands Lens |
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What structures arise from ectoderm derived from the neural tube?
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Retina
Nerve fibres of optic nerve Smooth muscle of iris |
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What structures are arise from mesenchyme?
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Corneal stroma
Sclera Choroid Iris Ciliary musculature Part of vitreous body Cells lining anterior chamber |
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What structures arise from neural crest tissue?
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Corneal endothelium
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What structure induces the lens to develop?
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The presence of the optic vesicle induces the lens to develop
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What structures are induced by the lens?
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The presence of the developing lens induces the formation of the cornea and and stimulates development of the vitreous
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Describe the steps in the development of the rudimentary eyeball?
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- Rudimentary eyeball develops as ectodermal diverticulum
- From lateral aspect of forebrain - Grows out laterally toward side of head - End becomes slightly dilated to form optic vesicle - Proximal portion becomes constricted for form optic stalk - Small area of surface ectoderm overlying optic vesicle thickens to form lens placode - Lens placode invaginates and skins below surface ectoderm to form lens vesicle - Optic vesicle becomes invaginated to form double-layered optic cup - Inferior edge of optic cup is deficient - This notch is continuous with groove on the inferior aspect of the optic stalk (called optic fissure or choroidal fissure) - Vascular mesenchyme grows into optic fissure - Takes with it the hyaloid artery - Fissure becomes narrowed by growth of its margins around the artery - Fissure closes forming optic canal inside the optic stalk (at 7th week) - Lens vesicle loses contact with surface ectoderm - Lies within mouth of optic cup - Edges of which form future pupil |
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What structures may be included in a coloboma?
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Pupil
Ciliary body Choroid Optic nerve |
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From what structure does the retina develop?
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Optic cup
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What are the developmental layers of the retina?
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Pigment layer
Neural layer |
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From what structure is the pigment layer of the retina formed?
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Outer thinner layer of the optic cup
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