The chiasmata can slip off the ends of the bivalents , and thus chiasma frequency may be reduced by terminalization .
有时交叉可以从二价体末端处滑开，因此移端过程可以降低交叉频率。
But here , too , chiasma is to be found , since it is this last field , supposedly created to perceive things in diminished lighting , which provides the maximum possibility of perceiving the effects of light .
Methods 80 adult cadaveric heads were dissected to study the shapes of optic chiasma and its neighbouring hypophyses , internal carotid artery and its blood-supplying arteriolae and the surrounding areas .
方法80个成人脑研究视交叉及其相邻的垂体、颈内动脉及其供血小动脉的形态和毗邻。
Conclusion the compression of optic nerves and optic chiasma is responsible for different types of visual field defects caused by saddle area tumors .
结论颅底肿物引起不同类型的视野缺损的原因与压迫视神经、视交叉相关。
Objective to provide morphological evidences for visual field defects caused by the compression of optic nerves and optic chiasma by saddle area tumors .
