Sagittal Plane Definition

The sagittal plane is an anatomical boundary that exists between the left and right sides of the body. The sagittal planes runs parallel to the longitudinal axis of the organism, or from the mouth to the tail. The direction toward the sagittal plane is called medial, while the direction away from the sagittal plane is known as lateral. The sagittal plane is similar to the coronal or frontal plane, which also runs with the longitudinal axis. The transverse plane crosses the sagittal plane perpendicularly, and divides the organism into dorsal and ventral parts. A section that runs parallel to the sagittal plane is called a parasagittal plane. The sagittal plane can be seen in relation to the other planes in the following image.

Planes of Section

Human anatomy has a slightly different orientation. This is not due to any difference in human anatomy, but simply the fact that humans tend to orient themselves vertically, while other animals orient themselves horizontally. The sagittal plane still divides humans into left an right halves, but runs vertically instead of horizontally as seen in the following image.

Planes of Body

  • Coronal Plane – A division along the longitudinal axis which separates the dorsal from the ventral side.
  • Transverse Plane – A plane which bisects the organism perpendicularly to the longitudinal axis.
  • Medial – An anatomical direction towards the sagittal plane.
  • Lateral – A description of the anatomical direction that points away from the sagittal plane.


1. You are a wildlife technician, and you are helping airlift a baby elephant with a helicopter. The harness has two attachment points. The instructions on the elephant harness tell you to place the elephant in the harness with the attachment points in line with the sagittal plane. How do you put the elephant in the harness?
A. Place the harness around the elephant’s belly
B. One attachment point should be near the head, while the other is near the tail
C. Put the elephant’s front legs, but not back, in the harness

Answer to Question #1
B is correct. The sagittal plane runs from the head to the tail, and therefore the harness should run in the same direction. If the harness were to run with the transverse plane, then around the belly would be the appropriate position. While this is a silly example, understanding anatomical terms is important, and allows you to appropriately decipher scientific instructions.