When someone talks to us, we’re only able to understand them if we know their language. Well… the same thing goes for anatomy!

To study anatomy and communicate among peers, we have to use specialized terminology that helps us describe the structures of the human body, where exactly they’re located, and their relationship to one another.

If I tell you to look at the right-most finger of your hand - which one will it be? Your pinkie? Your thumb? It will depend on the position of your hand and whether you're looking at the back or the palm. This is why all anatomical descriptions are expressed in relation to one consistent position to eliminate any ambiguity.

Anatomical position is the position that is globally adopted for anatomical and medical descriptions of the human body. Now, let’s describe the position the body is in when we refer to anatomical position.

When a person is in the anatomical position, they are standing straight with their legs close together, their feet parallel to one another, toes directed forward, their arms are down at their sides with the palms of their hands facing forward, and they are keeping their head up and gazing straight forward. All descriptions of the body refer to the position shown here.

Now, if we’re looking at someone in anatomical position, there are four imaginary planes that intersect the body to help us with anatomical descriptions.

First, we have the median plane, which is an imaginary vertical plane going through the body’s midline, over structures such as the nose and belly button, separating the body into right and left halves.

Second, are sagittal planes, which are also vertical planes, but aren't fixed, meaning that they could be placed anywhere parallel to the median plane, dividing the body into uneven left and right parts. You might also hear the term paramedian plane, which describes a sagittal plane that is near the median plane.

Next we have frontal planes, also known as coronal planes. These imaginary planes are also vertical, but perpendicular to the sagittal and median planes, meaning they go from left to right, separating the body into a front portion and a back portion.

Finally, we have transverse planes, which are the only horizontal planes, and thus are also known as - you’ve guessed it! - horizontal planes. These planes are perpendicular to the median and sagittal planes as well, but they divide the body into an upper portion, and a lower portion. In radiology, it’s also common to use the term axial plane, which is short for transaxial plane.