What is the name of the vertical plane that divides the body into right and left portions?

The vertical plane that divides the body into right and left portions is called the sagittal plane. This plane runs from the front of the body to the back and divides it into two halves, one side being the right and the other the left.

The midsagittal plane is a specific type of sagittal plane that runs directly down the middle of the body, creating equal right and left halves. While it is also a correct term, the general term "sagittal plane" encompasses both the midsagittal and any other sagittal variations that do not necessarily split the body into equal halves.

In contrast, the transverse plane divides the body horizontally into upper and lower portions, and the coronal plane (or frontal plane) separates the body into anterior (front) and posterior (back) sections. Thus, identifying the correct term as the sagittal plane accurately represents the type of division described in the question.