Planes and Directional Terms

Anatomical Position

A standard reference position where the body is upright, facing directly forward with feet flat and arms at the sides, palms facing forward.

Plane

A flat surface along which a body or structure can be cut.

Sagittal Plane

Divides the body vertically into right and left parts.

Midsagittal (median) Plane

A plane that lies on the midline of the body.

Frontal (coronal) Plane

Divides the body vertically into front and back parts.

Transverse (horizontal) Plane

Divides the body horizontally into top and bottom parts.

Inferior (Caudal)

Refers to a position lower in relation to another structure, meaning away from the head.

Superior (Cranial)

Refers to a position higher up in relation to another structure, meaning toward the head.

Lateral

Refers to a position that is away from the midline of the body.

Medial

Refers to a position that is toward the midline of the body.

Proximal

Refers to a position nearest to the point of attachment of a limb or structure.

Distal

Refers to a position that is farthest away from the point of attachment or origin.

Superficial (External)

Refers to a position closer to the surface of the body.

Deep (Internal)

Refers to a position farther from the surface of the body.

Dorsal Cavity

The body cavity that contains the brain and spinal cord, divided into cranial and vertebral cavities.

Ventral Cavity

The body cavity located in front of the body, containing the thoracic and abdominopelvic cavities.

Thoracic Cavity

The portion of the ventral cavity that is surrounded by the ribs, sternum, and vertebral column.

Abdominopelvic Cavity

The cavity below the diaphragm that houses organs in the abdominal and pelvic regions.

Pleural Cavities

The spaces surrounding the lungs within the thoracic cavity.

Mediastinum

The region in the thoracic cavity between the lungs that contains the heart and other structures.