Many students find anatomy difficult because they see it as pure memorization. I try to emphasize the conceptual side to make it more intuitive. You will still need to learn fundamental facts and terms before you can reason your way through anatomy, though.
Directional terms are necessary basics. Instead of saying up, down, front, back, we use special terms to avoid confusion. Suppose a patient is lying on their back; does "top" refer to their belly or to their scalp? Does "behind" refer to the side of the body opposite where you are standing, or to the patient's back? We need terms whose meaning doesn't change when body position changes.
Stand up, face forward, point your toes forward, hang your hands at your sides, face your palms forward. This is anatomical position, and all directional terms assume that the body is in this position. Directional Terms:
- Anterior - front, in front of. Your belly button is anterior to your spine.
- Posterior - back, behind. Your spine is posterior to your belly button.
- Superior - above, higher. Your knee is superior to your ankle.
- Inferior - below, lower. Your ankle is inferior to your knee.
- Medial - closer to the midline. Usually "midline" refers to the middle of the body, which is an imaginary plane dividing the body into left and right halves. Your right eye is medial to your right ear.
- Lateral - farther from midline. Your right ear is lateral to your right eye.
- Proximal - closer to the central mass of the body. In reference to tubes like the gut and blood vessels that allow materials to flow through them, it means "closer to the source," or "upstream." The elbow is proximal to the wrist. The throat is proximal to the stomach.
- Distal - farther from the central mass of the body. Referring to tubes, it means "farther from the source" or "downstream." The wrist is distal to the elbow. The stomach is distal to the throat.
- Right - always refers to the right side of the body in question, never to the right side of the observer.
- Left - always refers to the left side of the body in question.
Stand in anatomical position again. Your palm is anterior to the back of your hand. Turn your hand so your palm faces behind you. Your palm is still anterior to the back of your hand, because "anterior" is based on the body being in anatomical position. Now lie on your belly. Your head is still superior to your neck and your belly button is still anterior to your spine. Stretch your arm straight out past your head. Your hand is still inferior to your elbow, though it's less confusing if you say the hand is distal to the elbow. It's worth mentioning that you will likely encounter these terms being used more loosely if you go into clinical practice. Academic anatomy and clinical anatomy have quirky differences, but for this blog, I'll stick with the strict academic definitions I just gave.
Other important terms to get you started are those describing movement of joints. More to come on this soon.
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