Directional Terms & Regional Terms


Have you ever been trying to get somewhere following directions that have left and right in the instructions? While you may have gotten to your destination, you may also think, that left or right are not really universal directions; left or right really depends on your orientation. For this reason, it’s sometimes easier to navigate using the cardinal points (north, south, east, west) because they aren’t dependent on your orientation. East is always east, even if your facing south! 


For this same reason is why we using universal set of terms to describe direction and region in anatomy. It may not seem like a big deal, but these terms are used so we can be more specific when describing something and to potentially reduce medical error. Many of these terms are derived from ancient Greek and Latin words. Because these languages are no longer used in everyday conversation, the meaning of their words does not change.



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.


Directional Terms


Directional anatomical terms are essential for describing the relative locations of different body structures. For instance, an anatomist might describe one band of tissue as “inferior to” another or a physician might describe a tumor as “superficial to” a deeper body structure. These terms usually come in pairs, with one word meaning a specific direction and the paired word meaning the opposite. Let’s take a look at some common directional terms:

Directional TermCommon TermExample
Superiorabove; higherChest is superior to the abdomen.
Inferior below; lowerHeart is inferior to the brain.
Ventralbelly; undersideOur abdomen is on the ventral side of our body.
Dorsaltowards the spineOur spine is the dorsal side of our body.
AnteriorfrontOur eyes, nose and mouth are on the anterior side of our head.
Posteriorback; behindShoulder blade would be consideredposterior.
Superficaltowards the surfaceSkin is a superficial organ.
Deepaway from the surfaceBelow the skin are deep tissues.
Caudaltowards the 'tail'The coccyx is the most caudal vertebrae in our spine.
Cranialtowards the head
LateralouterEars and shoulders would be consider lateral.
Medialtowards the middle/ midlineOur sternum/brestbone would be a considered medial.
Proximalcloser to point of attachment or trunkThe elbow proximal to the wrist.
Distalfurther from point of attachment or trunkFingers are distal to the wrist
Directional_Terms

You may have noticed that these terms are always communicating a position or direction relative to something else. For example, your abdomen would be superior if  relative to your legs, but inferior relative to your chest. More commonly, the terms are used to locate a specific locations within the same area – or on the same bone. Let’s consider your upper arm. If we were to referring to a location of your upper arm as superior, do you think that would mean closer to the armpit, or closer to the elbow?


 

The difference between ventral/dorsal and anterior/posterior

For two legged animals, the answer is pretty straightforward: not much. Since the front of our body is also the ‘bellyside,’ there used somewhat interchangably. Likewise for our back (posterior) and ‘spine side’ (dorsal). However, for four legged animals, this isn’t the case.  

ventral, dorsal, anterior, posterior on a four legged animal

Regional Terms


Just as maps are normally oriented with north at the top, the standard “body map” is that of a 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 forward. Using this standard position reduces confusion since it does not matter how the body being described is oriented. For example, a scar in the “anterior (front) carpal (wrist) region” would be present on the palm side of the wrist. The term “anterior” would be used even if the hand were palm down on a table.

regional terms
Regional TermCommon Name
Abdominal abdomen
Antecubitalelbow (ventral side)
Axillaryarmpit
Brachialupper arm
Buccalcheek
Calcanealheel
Carpalwrist (small bones)
Cephalichead
Cervicalneck; (also cervix)
Coxalhips
Digitalfingers and toes
Femoraltight; femur
Glutealbutt
Inguinalgroin
Lumbarlower back
Nasalnose
Occipitalback, base of head
Olecranalpoint of elbow
Oralmouth
Orbitaleyes
Patellarkneecap
Pelvicpelvis
Sacralrelated to the sacrum
Sternalbrestbone
Tarsalankle (small bones
Thoracic chest cavity
Umbilicalbellybutton
Vertebralspine
  1. Betts, J. Gordon, et al. “1.6 Anatomical Terminology.” Anatomy and PhysiologyOpenStax, https://openstax.org/books/anatomy-and-physiology/pages/1-6-anatomical-terminology.
     
    *Some of the text and images on this page were shared directly from OpenStax under the creative commons license CC by-sa 3.0. Access for free at https://openstax.org/books/anatomy-and-physiology/pages/1-introduction