This is the vertical plane passing lengthwise through the midline of the body from front to back, dividing it into right and left halves, except for such internal organs as the heart and liver that do not lie in the midline.

• 纵向由前向后贯穿人体正中线的垂直面，将人体分为左、右两半，一些不在正中线上的内脏如心、肝等除外。