Uniform Standards Of Human Anatomy (2): Terms Of Direction

Terms of Direction

Take the standard posture as the standard, and use the prescribed azimuth terms to correctly describe the mutual positional relationship of various organs and structures of the human specimen.

1. Superior and inferior: According to the anatomical posture, the head is superior and the feet are inferior. In comparative anatomy or embryology, due to the relationship between animal and embryo position, cranial is often used instead of superior, and caudal is used instead of inferior.

2. anterior and posterior: those who rely on the ventral surface of the body are anterior, and those who rely on the back are posterior. It is usually called ventralis and dorsalis in comparative anatomy. Palmar and dorsal are often used when describing hands.

3. Medialis and lateralis: Take the midline of the body as the standard, the one closer to the midline is medialis, and the one relatively far away from the midline is lateralis. For example, the thumb of the hand is lateralis and the little finger is medialis. When describing the structure of the upper limbs, because the ulna and radius of the forearm are juxtaposed, the ulna is in the medialis, and the radius is in the lateralis, ulnar can be used instead of medialis and radial instead of lateralis. The lower limbs have tibia and fibula side by side, the tibia is in the medialis, and the fibula is in the lateralis, so they can also be called tibial and fibular.

4. Interior and exterior: used to indicate the relationship between certain structures and cavity, and should be distinguished from interior and exterior.

5. Superficial and deep: The part close to the body surface is called superficial, and the part relatively far away from the body surface is called deep.

6. Proximal and distal: In the limbs, the relationship between the parts is often described by proximal and distal, that is, the root near the trunk is proximal, and the relatively distant or distal part is distal.