Anatomical Terminology

Though we are familiar with the common terms of many parts and region of the body, we should learn to use internationally accepted anatomical names/terms.

This introduces us to a wider application of medical terminology. It also promotes clear communication internationally, which is essential in the practice of clinical medicine, dentistry and allied health sciences.

A) Body Positions
The following are the body positions/postures of the human body during clinical examination/cadaver dissection/anatomical description.

Anatomical Position:
* Standing erect
* Eye look straight to the front
* Upper limbs by the side of the body, palms facing forward.
* Lower limbs together digits (toes) pointing forward.

• Supine Position
  * Lying down on the back with the face directed upwards.
• Prone position
  * Lying down facing the ground.
• Lithotomy position
  * Lying down on your back with fully flexed (knees pointing to the roof) and abducted (widely spread) thighs.

B) Anatomical planes
These are imaginary planes (lines that pass through the body when it is in anatomical positions. They help identify and study the position of structure/organs in relation to one another. They further help in making precise surgical incisions.

1. Median Plane: Imaginary vertical plane passing longitudinally through the middle of the body from front to back, it into right and left halves.
2. Sagittal Planes: Imaginary vertical planes passing through the body parallel to the median plane.
3. Coronal Planes: These are imaginary planes passing through the body at right angle to the median plane, dividing it into anterior (front) and posterior (back) portions.
4. Horizontal Planes: These are imaginary planes passing through the body at right angles to both the median and coronal planes. This plane is parallel to the ground. This plane divides the body into two superior (upper) and inferior (lower) parts.
5. Transverse Planes: An imaginary plane at right angles to the vertical planes (coronal and sagittal).
6. Oblique Planes: Any plane other than those mentioned above, they slant or deviate from the other planes.

C) Terms of Relationship

• Superior (cranial) - Nearer to the head
• Inferior (caudal) - Nearer to the feet
• Anterior (ventral) - Nearer to the front
• Posterior (dorsal) - Nearer to the back
• Medial - Nearer to median plane
• Lateral - Farther from the median plane.

D) Terms of Comparison
Compare the relative positions of two structures with each other.

• Proximal - Nearer to the trunk/point of origin
• Distal - Further from the trunk/point of origin
• Superficial - Nearer to/on the surface
• Deep - Farther from the surface
• External (outer) - Towards/on the exterior
• Internal - Towards/in the interior
• Central - Nearer to/towards the center
• Peripheral - Further/away from the center
• Parietal - External wall of a body cavity
• Visceral - Pertaining to coverring of an organ
• Ipsilateral - On the same side of the body
• Contalateral - On the opposite side of the body.

E) Terms describing Movements at Joints

• Flexion - Bending/making a decreasing angle between the bones or parts of the body. In this movement there is an approximation of flexor surfaces.
• Extension - Straightening of a bent part or making an increasing of the body. In this movement there is an approximation of extensor surfaces.
• Abduction - Moving away from the median plane.
• Adduction - Moving towards the median plane.
• Rotation - Moving along the axis.
• Medial rotation - Inward rotation.
• Lateral rotation - Outward rotation.
• Circumduction - Circular movement combining flexion, extension, adduction and abduction.
• Eversion - Raising the lateral border of the foot.
• Inversion - Raising the medical border of the sole of the foot.
• Pronation - Rotation of the forearm so that the palm is turned backwards.
• Supination - Rotation of the forearm so that the palm is turned forwards.
• Protrusion - Moving anteriorly (forward).
• Retraction - Moving posteriorly (backward).

F) Terms related to Muscle

• Origin - The end of the muscle, which shows relatively less movement during contraction.
• Insertion - The end of the muscle, which shows relatively more movement during contraction.
• Belly - The flesh and contractile part of the muscle.
• Tendon - The fibrous, non-contractile part of the muscle.
• Aponerurosis - The flattened, sheet of dense connective tissue, which attaches the muscles to the bone/skin.
• Raphae - A fibrous band made up of interdigitating fibers of the aponeurosis of muscles.

G) Terms related to Vessels

• Artery - Carry oxygenated blood away from the heart.
• Veins - Carry deoxygenated blood towards the heart.
• Capillaries - Microscopic vessels connecting arterioles to venules.