视神经交叉(optic chiasma),视神经由视神经节细胞的轴突构成。它在向脑内传入时左右视网膜鼻侧的视神经构成视交叉,而颞侧纤维不交叉。这样右侧视野的信息经左侧视束(由左眼颞侧的视神经和右眼鼻侧的视神经构成)入左侧视皮层;左侧视野的信息经右侧视束(由右眼颞侧的视神经和左眼鼻侧的视神经构成)入右侧视皮层。视束大部分入视皮层, 小部分入上丘和下丘脑。
在人脑中央深处有个叫做下丘脑的部位(就在视神经交叉处正上方),人体自带的时钟就在这里运转。
Deep inside the brain, in a region called the hypothalamus (right above where our optic nerves cross) the internal clock is ticking.
其中1例患者,强化病灶局限于右侧视神经且延伸至视交叉前缘,其它部位均为受累(图8)。
In one case, the enhancement was confined to the right optic nerve, extending to the prechiasmal border without any other parenchymal involvement (Fig 8).
目的为脑底肿瘤压迫视神经、视交叉引起视野缺损原因提供形态学依据。
Objective To provide morphological evidences for visual field defects caused by the compression of optic nerves and optic chiasma by saddle area tumors.
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