anatomical plane spatial BSPO:0000400 plane FMA:242982 anatomical cross-section section A flat 2D plane intersecting an anatomical continuant, dividing it into two adjacent portions. anatomical section These anatomical sections are applicable to most bilaterally symmetrical animals, but bipedal animals such as humans have more complex usage of these terms. For example, in post-embryonic humans a coronal plane is vertical and a transverse plane is horizontal, but for embryos and quadrupeds a coronal plane is horizontal and a transverse plane is vertical. cross-section anatomical boundary