始段 meaning in English

initial segment

Initial segment of axon
轴突起始段
Note : you have to work with the hidden text displayed ( tools ? options ? view - formatting marks ? all checkbox must be selected , then click the show / hide button in the standard toolbar ) as the source segments and some coding are formatted as hidden text
说明：须使用隐藏文本显示方式（工具-选项-流览-格式化标记-所有的复选框必须选中,然后在标准工具栏中点击显示/隐藏按钮）因为源始段与一些代码格式化为隐藏文本。