Directional terms describe the position of external structures.
Directional terms:
- left & right
- anterior & ventral
- superior & inferior
- proximal & distal
- medial & lateral
To describe internal structures we need to cut the body into slices called planes/ sections.
4 anatomical planes are:
1. sagittal
2. frontal
3. transverse
4. oblique
Left and right refers to the left and right sides of a person in anatomical position.
Not you as an observer!
Anterior/ ventral = front of the body
Posterior/ dorsal = back of the body
The navel is on the anterior/ ventral surface of the body.
The heel is posterior/ dorsal to the toes.
Superior = above/ towards the head
Inferior = below/ towards the feet
,Proximal and distal are only used to describe the location of 2 points on the SAME limb.
Limb could be an arm or leg.
Proximal = closer to where the arm/ leg inserts into the body
Distal = further away from where arm/ leg inserts into the body
The knee is proximal to the ankle.
The wrist is distal to the elbow.
Only use proximal and distal for 2 points on the same limb.
Proximal and distal is not for a point not on the limb.
Therefore use superior or inferior.
Medial = closer to the midline of the body
Lateral = further from the midline of the body
Thumb is lateral to the little finger.
, Sagittal plane is a lengthwise/ vertical cut.
Sagittal plane divides the body into left and right portions.
If the cut passes through the midline of the body then it is called the mid-sagittal plane.
If the cut doesn’t passes through the midline of the body then it is called the parasagittal plane.
Frontal plane divides the body into anterior and posterior portions.
Transverse plane is a horizontal cut.
Transverse plane divides the body into superior and inferior portions.