Medical Orientation Words with Reference to the Body
(there are certain anatomic terms which present various situations; for example, a body part may be horizontal, as opposed to vertical; in front as opposed to being behind or at the back; above as opposed to being under, etc.)
anterior
The front, as opposed to the posterior; for example, the breastbone is part of the anterior surface of the chest.
anteroposterior, AP
From the front to the back, as opposed to posteroanteror.
When a chest X-ray is taken with the patient's back against the film plate and the X-ray machine is in front of the patient, it is referred to as an AP, or anteroposterior, view.
ascending
Going upward.
The ascending aorta is the portion of the aorta that ascends, going upward as it leaves the heart to form the beginning of the arch of the aorta.
caudad
Toward the feet (or tail, in embryology), as opposed to cranial.
cranial
Toward the head, as opposed to caudad.
deep
Away from the exterior surface or farther into the body, as opposed to superficial.
descending
Going down.
The descending aorta is the portion of the aorta that descends, going downward from the top of the arch of the aorta.
distal
Farther from the beginning, as opposed to proximal or toward the beginning.
dorsal
The back, as opposed to the ventral or the abdomen.
external
Situated on the outside.
extra
A Latin prefix that indicates "outside of".
horizontal
Parallel to the floor; a plane that passes through the standing body that is parallel to the floor.
inferior
Below, as opposed to superior or above.
internal
Situated on the inside as opposed to the surface or exterior.
intra
A Latin prefix indicating "within" as opposed to the "outside".
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