Anatomical directional terms are the standard language used to describe the location of body structures relative to one another. These terms are based on the anatomical position, which is the reference position used universally in anatomy.
The Anatomical Position
The anatomical position is defined as a person standing upright with:
- Feet together and pointed forward
- Arms at the sides
- Palms facing forward (supinated)
- Head and eyes facing forward
All directional terms describe the position of structures relative to this standard reference position, regardless of the actual position of the body.
Primary Directional Terms
Superior and Inferior
Superior (cranial/cephalic) refers to a structure being closer to the head or higher than another structure. The heart is superior to the diaphragm.
Inferior (caudal) refers to a structure being closer to the feet or lower than another structure. The stomach is inferior to the diaphragm.
Anterior and Posterior
Anterior (ventral) refers to the front of the body. The sternum is anterior to the heart.
Posterior (dorsal) refers to the back of the body. The esophagus is posterior to the trachea.
Medial and Lateral
Medial refers to a structure being closer to the midline of the body. The sternum is medial to the clavicle.
Lateral refers to a structure being farther from the midline. The lungs are lateral to the heart.
Intermediate
Intermediate describes a position between medial and lateral. The clavicle is intermediate between the sternum (medial) and acromion (lateral).
Proximal and Distal
These terms are used primarily for the limbs.
Proximal means closer to the trunk or point of origin. The elbow is proximal to the wrist.
Distal means farther from the trunk or point of origin. The fingers are distal to the wrist.
Superficial and Deep
Superficial (external) refers to structures closer to the surface of the body. The skin is superficial to the muscles.
Deep (internal) refers to structures farther from the body surface. The femur is deep to the quadriceps muscles.
Ipsilateral and Contralateral
Ipsilateral refers to structures on the same side of the body. The right arm and right leg are ipsilateral.
Contralateral refers to structures on opposite sides of the body. The right arm and left leg are contralateral.
Intermediate Terms
Cranial and Caudal
Cranial refers to toward the head. Caudal refers to toward the tailbone (sacrum).
Palmar and Dorsal (Hand)
Palmar refers to the palm side of the hand. Dorsal refers to the back of the hand.
Plantar and Dorsal (Foot)
Plantar refers to the sole of the foot. Dorsal refers to the top of the foot.
Prone and Supine
Prone describes a body lying face down. Supine describes a body lying face up.
Clinical Application
Understanding directional terms is essential for:
- Describing the location of injuries and pathologies
- Interpreting medical imaging reports
- Communicating surgical approaches
- Understanding physical examination findings
For example, a radiologist might describe a tumor as “located in the superior pole of the left kidney” or a surgeon might plan an incision “anterior to the sternocleidomastoid muscle.”
Summary Table
| Term | Meaning | Example |
|---|---|---|
| Superior | Toward the head | Heart is superior to diaphragm |
| Inferior | Toward the feet | Stomach is inferior to diaphragm |
| Anterior | Front | Sternum is anterior to heart |
| Posterior | Back | Esophagus is posterior to trachea |
| Medial | Toward midline | Sternum is medial to clavicle |
| Lateral | Away from midline | Lungs are lateral to heart |
| Proximal | Closer to trunk | Elbow is proximal to wrist |
| Distal | Farther from trunk | Hand is distal to wrist |
| Superficial | Near surface | Skin is superficial |
| Deep | Away from surface | Bone is deep to muscle |