Orientation terminology for the study of 2-D and 3-D structures in biology
Orientation terms, derived from Greek or Latin, are used to define the position of certain structures with respect to others in organisms and to certain anatomical surfaces in sections. Frequently used terms are regrouped in the tables here below (main source: manuals written by Dr. François van Herp)
Anatomical terms of location and orientation in of animals and man: indications of the direction
Term
Explanation and example
Anterior
Directed towards the front Towards the front legs of a cat
Bilateral
On two sides Limbs are laid out bilaterally in man
Caudal
Directed towards the tail The stomac is located caudal with respect to the lungs
Cranial
Directed towards the head The heart is located cranial with respect to the liverTD>
Distal
In the direction of the edge of the structure the elbow is distal with respect to the shoulder
Dorsal
In the direction of the back The vertebral column is located dorsal with respect to the and the esophagus and the trachea
Inferior
Directed downwards The Musculus rectus inferior:, that is the low right eye muscle, as opposed to the Musculus rectus superior, the upper right eye muscle
Lateral
Directed towards the side The lungs are located laterally with respect to the sternum
Medial
Directed towards the middle line (median) The eye is located more medial than the ear
Posterior
Directed towards behind The Musculus tibialis posterior is the muscle at the back side of the tibia
Proximal
Directed towards the beginning/base of the structure The elbow is located proximal with respect to the wrist
Radial
With equal parts arranged around a central body the arms of a sea star are laid out radially; they show radial symmetry
Rostral
Directed towards the nose or the mouth the nose is rostral compared to the occiput
Superior
Directed upwards The Musculus rectus superior, the right upper eye muscle, as opposed to the Musculus rectus inferior:, the lower right eye mucle
Unilateral
On one side The nose is laid out unilaterally
Ventral
Directed towards the abdomen (belly) The sternum is located ventral with respect to the heart
Surfaces in sections
Sections in animals/man
Divides the organism in
Coronal/frontal
a dorsal and a vetral part oneach side
Sagittal / length
left and right side. (Median section is exactly in the middle)
Transversal
a caudal and a cranial part
Sections in plants in wood
Divides the organism in
Cross (transverse)
perpendicular to the long axis
Longitudinal
along the long axis
Radial
according to the rays
Tangential
parallel to the longitudinal section (see illustration)
