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一、眼与眼的中枢的发育胚胎,胎儿期的发育当胚胎2月时,便已形成具有各个部分的胚限。它生成自视杯及其周围的组织。视杯系经由胚胎2周末的眼原基视窝于第3周发育为视泡渐次演化而来。视杯外层衍化为视网膜色素上皮层,内层演变为神经感觉部视网膜组织。感觉部的节细胞发出神经纤维经眼裂进入视茎,于胚胎第7周在脑垂体前进入前脑下面并部分交叉,形成视交叉。9(1/2)周时形成视束。与此同时于胚胎第8周,间脑外膝状体出现主要传导途径,第12周时外膝状体明显增大。胎儿第5～6月,脑出现中央裂、顶枕裂与楔叶。在此之前胎儿第4～5月时,视皮质开始分化。5月时视神经脑端出现髓鞘,渐向眼端生长,于出生时抵达眼球。因此,视觉系统的周边部分的视网膜、传导部分的视路以及中枢部分的视皮质,在出生
First, the eye and eye of the central developmental embryo, the development of the fetus when the embryo in February, they have formed with various parts of the embryo limit. It generates self-optic cup and its surrounding tissue. Visual cup through the embryo 2 weeks of ocular primordial nest in the third week of development as the bubble gradually evolved. Depending on the outer layer of the retinal pigment epithelium, the inner layer evolved into neuro-sensory retinal tissue. Sections of the sensory cells of the ganglion issue nerve fibers into the optic nerve via the fissure, in the seventh week of the embryo before the pituitary into the forebrain and partially cross, the formation of optic chiasm. 9 (1/2) weeks to form a visual tract. At the same time, in the eighth week of embryo, the main geni-medial geniculate pathways appeared, and the geniculate body increased obviously at the twelfth week. Fetal 5-6 months, the brain appears central fissure, the top of the occipital lobe and wedge leaves. Prior to the fetus from April to May, visual cortex began to differentiate. May when the optic nerve head appears medullary myelin, gradually growing to the ocular end, arrived at birth eye. Therefore, the retina in the peripheral part of the visual system, the visual pathway of the conduction part, and the visual cortex of the central part,