Page 13 - ASOP ROT Study Guide

 Sagittal axis - passes horizontally from posterior to anterior and is formed by the
intersection of the sagittal and transverse planes.

 Frontal axis - passes horizontally from left to right and is formed by the intersection
of the frontal and transverse planes.

 Vertical axis - passes vertically from inferior to superior and is formed by the
intersection of the sagittal and frontal planes.

Any transverse, coronal or sagittal plane must be parallel to the examples in Figure 3 and
the three types of planes are always at right-angles to each other. The sagittal plane which
passes through the middle of the body is known as the median plane. Other terms in common
use are mid-sagittal instead of median; and not so frequently, parasagittal instead of sagittal.
The median plane is the only plane of symmetry in the human body; the left half is a mirror
image of the right half (except in small detail).

We often imagine the body to have been cut and separated at a reference plane and then
viewed looking directly at the plane. This is sometimes called a cross-section.

3 . 2 Directional Terms

In skeletal anatomy, directional terms are required for describing viewing directions, relative
positions of body parts and relative directions of movement. The terms used in this module are
defined below and examples to illustrate each definition.

Superior or cranial - toward the head end of the body; upper (example, the hand is part of the
superior extremity).

Inferior or caudal - away from the head; lower (example, the foot is part of the inferior extremity).

Anterior or ventral - front (example, the kneecap is located on the anterior side of the leg).

Posterior or dorsal - back (example, the shoulder blades are located on the posterior side of the
body).

Medial - toward the midline of the body (example, the middle toe is located at the medial side of the
foot).

Lateral - away from the midline of the body (example, the little toe is located at the lateral side of the
foot).

Proximal - toward or nearest the trunk or the point of origin of a part (example, the proximal end of
the femur joins with the pelvic bone).

Distal - away from or farthest from the trunk or the point or origin of a part (example, the hand is
located at the distal end of the forearm).

Valgus - bent or twisted away from the median plane the big toe is in valgus when bent outwards in
a transverse plane

Varus - bent or twisted towards the median plane the foot is in varus when it is bent inwards in the
coronal plane