Directional Terms & Regional Terms
Anatomists and health care professional often use medical terminology that can be difficult to understand. However, the purpose of this language is to increase accuracy and reduce the chance for medical errors. For example, is an injury “above the wrist” located on the forearm two or three inches away from the hand or at the base of the hand? Is it on the palm-side or back-side? By using precise anatomical terminology, we eliminate the chance of making mistakes.
TL; DR
- Directional and regional terms are used in anatomy to precisely describe specific locations.
- Many of these terms were chosen from Greek and Latin root words.
Contents
Related Resources
Anatomical Position
To increase precision, anatomists standardize the way in which they view the body. Just as maps are normally oriented with north at the top, the standard body “map,” or anatomical position, is that of the body standing upright, with the feet at shoulder width and parallel, toes forward. The upper limbs are held out to each side, and the palms of the hands face. Using this standard position reduces since the anatomical terms are independent of the body’s orientated.
Directional Terms
When it comes to anatomy, directional terms are a universal way to help us describe relative locations. Its much more helpful to use the terms we are going to learn than it is to use common terms like up, down left and right. Why is that? It’s because common terms often require you to explain your perspective when your using them.
When we use these terms properly, there are two big benefits to using directional terms. One is that we’ll more accurately describe particular body parts/areas. And the other is that we’ll also increase the chances that the person with whom we’re communicating will understand us!
At first, learning these terms might seem difficult. It’s helpful to know that most of these terms are based on Latin words. For example, the term superior comes from the Latin root super- meaning above or over. A simple example can be seen below.
Common terms often require us to also explain our perspective, which can sometimes be confusing.
Have you ever tried giving a friend directions and you tell them to turn left on a particular street only to find them heading in the wrong direction? That’s because up, down, left and right are relative to your point of view. Directional terms like north, south, east and west are independent of perspective and are always the same.
| Directional Term | Origin | Meaning |
Example |
|---|---|---|---|
| Superior | super- (latin) | above | Head is superior to the chest. |
| Inferior | inferus (Latin) |
low; below |
Pelvis is inferior to the chest. |
| Ventral | venter (Latin) |
belly; underside | Abdomen is on the ventral side of our body. |
| Dorsal | dorsum (Latin) |
back | Spine is on the dorsal side of our body. |
| Anterior | ante (Latin) |
before; in front |
|
| Posterior | post (Lain) |
behind | |
| Superficial | super- (Latin) facies (Latin) |
"above face"; outer surface |
Skin is a superficial organ |
| Deep | Below the skin are deep tissues. |
||
| Rostral |
rostrum (Latin) |
break; toward the |
Our forehead is rostral to the top of our head. |
| Cranial | cranium (Latin) kranion (Greek) |
skull; towards the head |
Cervical vertebrae are most cranial. |
| Caudal | cauda (Latin) |
tail; toward the |
Tailbone is the most caudal vertebrae. |
| Lateral | later- (Latin) |
side; toward the |
The sides of our body are lateral. |
| Medial | medius (Latin) |
middle; towards the |
Sternum (brestbone) is medial |
| Proximal | proximus (Latin) |
nearest; closer to origin |
The proximal forearm is closer to the elbow. |
| Distal | dis- (Latin) |
apart; further from origin |
The distal forearm is closer to the wrist. |
Does Relative Location Matter when Using Directional Terms?
You may have noticed that directional terms are always communicating a position or direction relative to something else. For example, your abdomen is superior relative to your legs, but inferior relative to your chest.
More commonly, the terms are used to locate specific locations within the same area, on the same bone, or within an organ. Consider your upper arm for a moment. If we were to referring to a location on your upper arm as superior, do you think that would mean closer to the armpit, or closer to the elbow?
What's the Difference between Ventral vs. Anterior and Dorsal vs. Posterior?
These four terms are commonly confused because they are sometimes interchangeable. The anterior (front) side of our body, also happens to be the ventral (belly) side of our body, but for animals with four legs this isn’t necessarily true. If we look at the horse, the ventral (belly) side of the horse is it’s underside, where as the anterior (front) side of the horse is where it’s head is.
References
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Betts, J. Gordon, et al. “1.6 Anatomical Terminology.” Anatomy and Physiology, OpenStax, https://openstax.org/books/anatomy-and-physiology/pages/1-6-anatomical-terminology. License: CC BY 4.0 | License Terms: Edited & Adapted | Access for free https://openstax.org/books/anatomy-and-physiology/pages/1-introduction.