Lesson · S.1.1

General orientation of human anatomy

The shared vocabulary anatomy runs on: standard position, the three body planes, and the direction words the TEAS uses to locate structures.

ObjectiveS.1.1Read2 minExam weightHuman Anatomy and Physiology ≈ 41% of Science

By the end of this lesson you can

Describe anatomical position and explain why every directional term assumes it.
Name the three body planes and state what each one divides.
Apply direction terms such as superior, medial, and proximal to locate one structure relative to another.

Key takeaways

Anatomical position is the fixed reference point, standing, facing forward, palms forward.
The three planes are coronal (front and back), transverse (top and bottom), and sagittal (left and right).
Left and right always describe the body's own sides, not the viewer's.
Proximal means nearer the trunk, distal means farther from it, a pairing the TEAS tests with limb questions.
Regions and subregions give precise names to areas the broad terms cannot capture.

Check yourself

0 / 5

1Which description matches standard anatomical position?
2A plane that divides the body into top and bottom sections is called which plane?
3Which plane divides the body into left and right portions?
4According to the lesson, when using anatomical direction terms, left and right refer to whose perspective?
5The ribcage is described as lateral to the sternum. What does this tell you about the ribcage's position?

Practise more →

The three planes that slice the body

A plane is an imaginary flat surface used to divide the body so a structure's location can be described relative to it.

Coronal (frontal) plane divides the body into front and back.

Transverse (cross-sectional) plane divides the body into top and bottom.

Sagittal (median) plane divides the body into left and right.

Organs can be sliced along these same planes, which is why imaging terms like "cross-section" map directly onto the transverse plane.

Direction words describe one structure relative to another

Anatomical direction never refers to the viewer's left or right. It always refers to the body's own left and right, as if the body were describing itself.

Superior and inferior mean above and below.

Anterior and posterior mean toward the front and toward the back.

Lateral and medial mean farther from and closer to the midline that splits the body into left and right halves. The ribcage is lateral to the sternum, while the sternum is medial to the ribcage.

Proximal and distal mean closer to and farther from the point where a limb attaches to the trunk. The wrist is proximal to the fingers, since the fingers sit farther out.

Terms combine when a single word cannot capture the location, so a structure can be described as posteroinferior, meaning both behind and below a reference point.

Regions group structures by area

The body is also divided into named regions, since "the arm" is too broad for precise description. The main regions are the head, neck, trunk, upper limbs, and lower limbs, and each of these splits into smaller subregions, for example the antecubital region at the front of the elbow or the popliteal region behind the knee.