Cross section refers to the section perpendicular to the long axis of human body or organ. This part divides the human body into upper and lower parts. This part is parallel to the ground plane, also known as the horizontal plane. Cross section is also called cross section. The cross section is the surface exposed after cutting the object from the direction perpendicular to the axis of the object. Mathematically, when a plane is used to cut a three-dimensional figure, the cut figure is called a section, the transverse section is called a transverse section, and the longitudinal section is called a longitudinal section.

The cross section is the horizontal plane obtained by cutting the horizontal plane of the solid geometric figure.