Anatomical Terms and Planes

Overview

This lecture introduces essential anatomical terms for positions, directions, and body planes used to describe human anatomy accurately.

Anatomical Position and Reference

• The anatomical position has the subject standing erect, feet parallel, eyes and palms facing forward, and thumbs pointing outward.
• "Right" and "left" always refer to the subject’s (patient’s) sides, not the observer’s.
• Misidentifying right and left can lead to serious mistakes in medicine.

Directional Terms

• Superior: Toward the head or upper part of a structure (e.g., lungs are superior to the liver).
• Inferior: Away from the head or toward the lower part (e.g., small intestines are inferior to the stomach).
• Anterior (ventral): Toward the front of the body (e.g., ribs are anterior to the spine).
• Posterior (dorsal): Toward the back or behind (e.g., occipital bone is posterior to the frontal bone).
• Lateral: Away from the midline of the body (e.g., lungs are lateral to the heart).
• Medial: Toward the midline (e.g., trachea is medial to the clavicles).
• Intermediate: Between two structures (e.g., clavicle is intermediate between scapula and sternum).
• Proximal: Closer to the trunk of the body (e.g., scapula is proximal to the humerus).
• Distal: Farther from the trunk (e.g., wrist is distal to the elbow).
• Superficial (external): Toward or at the body surface (e.g., epidermis is superficial to the dermis).
• Deep (internal): Away from the surface (e.g., hypodermis is deep to the dermis).
• Contralateral: On opposite sides of the body.
• Ipsilateral: On the same side of the body.

Body Planes and Sections

• Coronal (frontal) plane: Divides body into anterior and posterior parts.
• Sagittal (longitudinal) plane: Lengthwise cut; mid-sagittal divides body into equal right and left halves.
• Transverse (cross-section) plane: Divides body into superior and inferior parts.
• Different imaging planes reveal different structures, making orientation important.

Key Terms & Definitions

• Anatomical position — Standard body reference position for anatomical terminology.
• Superior — Toward the head/upper part.
• Inferior — Away from the head/lower part.
• Anterior (ventral) — Toward the front.
• Posterior (dorsal) — Toward the back.
• Lateral — Away from the midline.
• Medial — Toward the midline.
• Proximal — Closer to the trunk.
• Distal — Farther from the trunk.
• Superficial — Closer to the body surface.
• Deep — Further from the body surface.
• Contralateral — Opposite sides.
• Ipsilateral — Same side.
• Coronal plane — Divides body front/back.
• Sagittal plane — Divides body right/left.
• Transverse plane — Divides body upper/lower.

Action Items / Next Steps

• Review anatomical terms and practice identifying body orientations.
• Read textbook sections and atlas material on anatomical planes and directional terms.
• Watch supplementary videos on medical terminology and how to study anatomy.