Directional Terms and Body Planes
Anatomical directional terms and body planes represent a universally accepted language of anatomy, allowing precise communication between anatomists and health professionals. The terms used to explain anatomical positioning are described in relation to one standard position called the anatomical position. This position is used to describe body parts and positions of patients regardless if they are lying down, on their side or facing down. In the anatomical position, the person is standing upright with arms to the side with the palms facing forward and thumbs pointing away from the body, feet slightly apart and parallel to each other with the toes pointing forward and the head facing forward and the eyes looking straight ahead.
Directional terms allow description of one body part in relation to another.
Anterior and Posterior
Anterior indicates that the body part in question is “in front of” or “front”. Posterior indicates that it is “in behind of” or “behind”.
Ventral and Dorsal
Ventral denotes towards the front of the body and dorsal means towards the back of the body.
Right and Left
Right indicates to the “right side of” and left indicates to the “left side of”.
Distal and Proximal
Distal indicates that it is away or farthest away from the trunk of the body or the point of origin of the body part. Proximal means that it is closest or towards the trunk of the body or point of origin.
Median or midline is an imaginary line down the middle of the body that splits the body into equal left and right parts.
Medial and Lateral
Medial is towards the median whereas lateral is away from the median and towards the side of the body.
Superior and Inferior
Superior is upwards or towards the vertex/top of the head whereas inferior indicates the opposite: below or towards the feet.
External and Internal
Sometimes known as superficial, external denotes towards the surface. Internal is also known as deep and denotes that it is away from the body surface.
Frontal and Occipital
Frontal refers towards the front of the brain whereas occipital means towards the back of the brain.
Body planes are imaginary planes or flat surfaces that cut through and section the body in its anatomical position.
The coronal plane is a vertical plane that divides the body into anterior (front) and posterior (back) parts.
The sagittal plane is also a vertical plane that splits the body into left and right parts. A sagittal plane that runs directly through the midline is also called the midsagittal plane or median plane.
The transverse plane is a horizontal plane. It divides the body into superior (upper) and inferior (lower) portions. In anatomy, they are also referred to as a cross section.