Imaginary planes marking the anatomic boundaries of the abdomen and thorax. Five horizontal planes run through the sternal jugular notch and the upper border of the symphysis pubis, with transtubercle, transpyloric, and transthoracic lines (bottom to top) spaced equally between them. Five vertical planes are comprised of 2 planes passing through each anterior superior iliac spine, one median plane, and 2 lateral sagittal planes (each bisecting the space between the iliac spine and the median plane.)