Overview
This lecture introduces the basics of anatomy, focusing on anatomical position, directional terms, and anatomical planes and sections essential for describing locations in the body.
Anatomical Position
- The anatomical position is a standard reference: facing forward, arms at sides, palms forward, and thumbs pointing outward.
- All anatomical descriptions are based on the body in this position, from the patient's or specimen's perspective.
Directional Terms in Anatomy
- Directional terms provide precise descriptions of locations and relationships between body parts.
- Anterior (ventral) refers to the front; posterior (dorsal) refers to the back.
- Superior means towards the top of the body; inferior means towards the bottom.
- Cranial (cephalic) means towards the head; caudal means towards the tail (used mainly for head/vertebral structures).
- Medial is towards the midline; lateral is towards the side.
- Superficial (external) means situated on or near the surface; deep (internal) means inside or farther from the surface.
- Proximal means closer to the point of origin (shoulder/hip); distal means farther from the point of origin.
Practice with Directional Terms
- The nose is inferior and medial to the eyes.
- The ears are lateral and posterior to the nose.
- Hair is superficial (or external) to the skull.
- The biceps brachii muscle originates proximally (or superiorly) on the scapula and inserts distally (or inferiorly) on the radius.
Anatomical Planes and Sections
- The body is studied using three main planes: sagittal, coronal (frontal), and axial (transverse/horizontal).
- Sagittal plane divides the body into left and right parts (midsagittal is equal halves, parasagittal is unequal).
- Coronal (frontal) plane divides the body into anterior and posterior parts.
- Axial (transverse, horizontal, cross-section) plane divides the body into superior and inferior parts.
- Radiology typically views axial sections from foot to head; anatomy traditionally views them from head to foot.
Practice with Planes and Sections
- Axial sections show anterior/posterior and right/left relationships.
- Sagittal sections show anterior/posterior and superior/inferior relationships.
- Coronal sections show right/left and superior/inferior relationships.
- Identifying posterior left regions uses the orientation described in the anatomical and radiological perspective.
Key Terms & Definitions
- Anatomical Position — Standardized body posture for anatomical reference.
- Anterior (Ventral) — Toward the front.
- Posterior (Dorsal) — Toward the back.
- Superior — Toward the top.
- Inferior — Toward the bottom.
- Cranial (Cephalic) — Toward the head.
- Caudal — Toward the tail.
- Medial — Toward midline.
- Lateral — Toward the side.
- Superficial (External) — Near the surface.
- Deep (Internal) — Away from the surface.
- Proximal — Closer to origin.
- Distal — Farther from origin.
- Sagittal Plane — Divides left/right.
- Coronal (Frontal) Plane — Divides front/back.
- Axial (Transverse, Horizontal) Plane — Divides top/bottom.
Action Items / Next Steps
- Memorize the anatomical position and all directional terms.
- Practice identifying planes and sections on diagrams or images.
- Complete any assigned readings or worksheets on anatomical terminology.