Anatomical Directions - a Brief Review
John Merck
Anatomical directions:
Standard terms used by anatomists for orienting themselves to the non-human vertebrate body.
Vocabulary:
- Anterior: Toward the front.
- Posterior: Toward the rear.
- Dorsal: Toward the top (i.e. the side with the vertebral column and spinal cord.).
- Ventral: Toward the belly.
- Lateral: Away from the plane of bilateral symmetry.
- Medial: Toward the plane of bilateral symmetry.
- Proximal: Toward the center of the body
- Distal: Away from the center of the body.
Usage:
- Can describe physical locations of anatomical features. E.G. "The distal phalanges."
- Can identify the direction from which a feature is being viewed. E.G. "The pectoral girdle in medial view." Same as "The medial aspect of the pectoral girdle."
- Can be combined. E.G. The antero-dorsal surface of the neural arch."
- Can be used as:
- adjectives (E.G. The anterior cervical vertebrae are specialized in tetrapods.) or
- prepositions (E.G. The head lies anterior to the torso).
- Add "-ly" to create adverbs. (E.G. Proceeding distally from the pelvis, one eventually encounters the tip of the tail.)
Synonyms: In special cases, alternative terms are used:
- The body:
- Cranial = anterior
- Caudal = posterior
- The skull:
- Rostral = anterior
- Palatal = ventral
- Occipital = posterior
Dental directions: A special case, requiring special terminology
- Mesial: Toward the symphysis (where the sides of the jaw come together.)
- Distal: Away from the symphysis (not your parents' "distal.")
- Labial: "Lipward" = Antero-lateral in front of mouth.
- Buccal: "Cheekward" = Lateral.
- Lingual: "Tongueward" = Medial.