Anatomical Terminology 

Anatomists and health care providers use terminology that can be bewildering to the uninitiated. However, the purpose of this language is not to confuse, but rather to increase precision and reduce medical errors. For example, is a scar “above the wrist” located on the forearm two or three inches away from the hand? Or is it at the base of the hand? Is it on the palm-side or back-side? By using precise anatomical terminology, we eliminate ambiguity. Anatomical terms derive from ancient Greek and Latin words. Because these languages are no longer used in everyday conversation, the meaning of their words does not change.

ANATOMICAL POSITION

The anatomical position refers to a person standing erect as in the diagram provided. This terminology has been adopted worldwide for anatomicomedical descriptions. Patients can be described in this way regardless of their actual position.

• Head, eyes and toes directed anteriorly (forward).
• Upper limbs by the side with the palms facing anteriorly.
• Lower limbs together with the feet directed anteriorly.

ANATOMICAL PLANES

Anatomical planes are descriptions of four imaginary planes (median, sagittal, coronal, horizontal) passing through the body in the anatomical position.

• Median -vertical plane passing longitudinally through the body dividing it into left and right halves. A plane parallel to the median plane is the paramedian plane.
• Sagittal -vertical plane passing through the body parallel to the median plane. It may be useful to give a point of reference by naming a structure intersected by the plane.
• Coronal -vertical plane passing through the body perpendicular to the median plane dividing it into anterior and posterior aspects.
• Horizontal -plane passing through the body at right angles to the median and coronal planes. A horizontal plane divides the body into superior (upper) and inferior (lower) parts.

Please note that some clinicians refer to horizontal planes as transaxial or axial planes that are perpendicular to the long axis of the body and limbs.

DIRECTIONAL TERMS

• Anterior indicates the front surface of the body and is used interchangeably with ventral.
• Posterior indicates the back surface of the body or nearer to the back. Dorsal is used interchangeably with posterior.
• Superior refers to a structure near the vertex (top of the skull).
• Inferior denotes a structure that is situated towards the soles of the feet.
• Medial indicates a structure is nearer to the median plane of the body.
• Lateral indicates a structure is farther away from the median plane.
• Rostral denotes the anterior part of the head.
• Caudal pertains to the tail.

Proximal and distal are directional terms used when contrasting positions nearer a specific point e.g. tumor (proximal) or origin of a limb and away from its attachment (distal).

• Proximal nearest the trunk or point of origin.
• Distal farthest from the trunk or point of origin.

Superficial and deep may also be used when contrasting positions in relation to the skin surface.

• Superficial closest to the skin surface.
• Deep farthest from the skin surface.