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The optic vesicles project toward the sides of the head, and the peripheral part of each expands to form a hollow bulb, while the proximal part remains narrow and constitutes the optic stalk. [1] [2] Closure of the choroidal fissure in the optic stalk occurs during the seventh week of development. The former optic stalk is then called the optic ...
The optic vesicles then develop into the optic cup with the inner layer forming the retina and the outer portion forming the retinal pigment epithelium. The middle portion of the optic cup develops into the ciliary body and iris. [7] During the invagination of the optic cup, the ectoderm begins to thicken and form the lens placode, which ...
These diverticula make their appearance before the closure of the anterior end of the neural tube; [1] [2] after the closure of the tube around the 4th week of development, they are known as the optic vesicles. Previous studies of optic vesicles suggest that the surrounding extraocular tissues – the surface ectoderm and extraocular mesenchyme ...
[7] The following is a proposed mechanism for how Shh patterns the ventral neural tube: A gradient of Shh that controls the expression of a group of homeodomain (HD) and basic Helix-Loop-Helix (bHLH) transcription factors is created. These transcription factors are grouped into two protein classes based on how Shh affects them.
Fgf3 and Fgf10 are suggested to play a role in otic induction in mice, as were Msx genes suggested to play a role in otic vesicle formation in chicks. Pax8 is expressed during the entirety of otic vesicle formation. Other genes found in the otic vesicle across species that may play a role in patterning include Hmx, Fox, Dlx, and Gbx genes.
During embryonic development of the eye, the outer wall of the bulb of the optic vesicles becomes thickened and invaginated, and the bulb is thus converted into a cup, the optic cup (or ophthalmic cup), consisting of two strata of cells.
Failure of closure of the anterior neuropore during embryogenesis will lead to anencephaly, the failure of the brain and skull to develop.In less severe situations it may lead to different forms of encephalocele (i.e. cranium bifidum).
Zemax is a software program used for designing and simulating optical systems. It is widely used in the field of optics and photonics for designing and analyzing the performance of lenses, cameras, telescopes, microscopes, and other optical systems.