Basic Anatomy Terminology: Anatomical Position, Planes and Directions with Examples

Before you study bones, muscles and organs, you need a shared language to describe exactly where any structure sits in the body. That language is anatomical terminology. It is the first thing health sciences students learn, and the thing they use most throughout their studies.

The anatomical position

Every anatomical description refers to one fixed position, called the anatomical position, whatever the body’s actual posture. In this position the person is:

• Standing upright, with the face and eyes looking forward.
• Upper limbs at the sides, with the palms facing forward.
• Feet close together, with the toes pointing forward.

Why does this matter? When a doctor describes an injury in a patient who is lying down, they describe it as if the patient were standing in the anatomical position, so there is no confusion.

Anatomical planes

A plane is an imaginary flat surface that cuts through the body. We use planes to describe sections and medical images. There are three main planes:

• Sagittal plane: divides the body into right and left parts. When it passes exactly through the middle, it is called the median (midsagittal) plane.
• Coronal (frontal) plane: divides the body into front and back parts.
• Transverse (horizontal) plane: divides the body into upper and lower parts, and is the plane most often used in CT scans.

Directional terms

These terms usually come in opposite pairs:

• Superior and inferior: the head is superior to the chest, and the foot is inferior to the knee.
• Anterior and posterior: the sternum is anterior to the heart, and the vertebral column is posterior.
• Medial and lateral: medial is closer to the midline of the body, lateral is farther from it. In the anatomical position, the little finger is medial and the thumb is lateral.
• Proximal and distal: used for the limbs. The elbow is proximal to the wrist, and the fingers are distal to the forearm.
• Superficial and deep: the skin is superficial to the muscles, and bone is deep to them.
• Ipsilateral and contralateral: describe two structures on the same side of the body or on opposite sides.

Movement terms

• Flexion and extension: flexion decreases the angle between two parts, such as bending the elbow, and extension restores it.
• Abduction and adduction: abduction moves a limb away from the midline, such as raising the arm sideways, and adduction brings it back.
• Rotation: movement around a long axis, which can be medial or lateral.

A tip for remembering

Do not memorize the terms as a list. Apply them to your own body as you study: touch your elbow and say “proximal to the wrist”, raise your arm sideways and say “abduction”. Practice fixes a term in minutes.

These terms are the focus of Unit 1 in Human Anatomy: Foundations and Terminology at Falak Academy, and the first lecture is free. If you are looking for a way to organize your study, read How to Study Anatomy in Your First Year.