Final answer:
The transverse plane divides the body into upper and lower portions, running horizontally across the body and differing from the midsagittal and frontal planes, which divide the body vertically and front to back, respectively.
Step-by-step explanation:
The body plane that divides the body into upper and lower portions is known as the transverse plane. This plane runs horizontally across the body and is perpendicular to the sagittal planes and the long axis of the body. It is also referred to as a horizontal plane, and when an image is produced via this plane, it is called a cross section. If the plane cuts at an angle, it is then described as an oblique plane. The transverse plane is distinct from both the midsagittal (median) plane, which divides the body into equal right and left halves, and the frontal (coronal) plane, which divides the body into anterior (front) and posterior (back) portions.