Note the three major planes. If you imagine a magic trick and someone getting sawed in half, that is the transverse plan. Trans is a Latin prefix that means something is moving across or through, examples: transaction, money is being moved across or exchanged, transduction, energy is being moved, and transfer. Getting comfortable with Latin roots will help, I will try to include them as often as possible, because I guarantee they will be reoccurring themes. The transverse plane is also called the horizontal plane. Planes are often used in medical imagining and in histology, the branch of biology dealing with the study of tissues, as often you will hear things referred to as 'cut in a transverse plane' or 'this slide was prepared from a transverse section'.
The second plane, the coronal plane, is what happens if somebody gets caught in a high speed automatic door. It is also often called the frontal plane. The third plane is called the sagittal plane and cuts the body in a plane between the eyes. It is often called the median plane, median referring to the middle. This is the only plane that has symmetry, the others do not.
Now take a look at the next image, we are going to add relations to our planes;
We will again start with the transverse, or horizontal, plane. As we travel up toward the head from the stomach and waist area, we are traveling superiorly. If we travel toward the feet we are traveling inferiorly. Think of related words, if something is superior it is above the object that or person that is inferior. 'Dave is a superior baseball player to Andrew, who is clearly inferior,' as an example. Similarly we describe anatomical things in relation to each other, the feet are inferior to the knees, the head is superior to the thorax, etc.
In the saggital plane, or median plane, we use the terms medial and lateral. Medial means located closed to the middle while lateral means further away. For example, if you are comparing your ear to your finger tips, you could say that your fingers are lateral to your ear, (side note: anatomical position is what we refer to as someone as pictured above, arms slightly out, palms forward. It is the standard anatomical reference), or that your ear is medial to your fingers. Be careful, these are comparative terms so they only mean something in relation to something else. They are commonly used to name muscles, nerves, or other things in the body that are similar in function or location; for example in the general region of your shoulder is a tangle of nerves called the Brachial Plexus (you will come to know and love/hate this structure). At a specific subdivision it splits into a medial cord, a lateral cord and a few others. For the most part anatomists named the body as they saw it, so as you can probably figure out the medial cord of the Brachial Plexus sits closer to the middle of the body and the lateral further away. This will all make more sense as we progress.
Lastly let us discuss the coronal plane, or frontal plane. For this plane we associate the terms anterior, from the latin ante- which describes something as in front of something else (think how an ante in a poker game is collected before the round begins, or antebellum referring to before the US Civil War), and posterior, from the latin post- denoting something as behind or after (think postoperative care is what you must do after a surgery to heal, postmortem refers to after death). If I am standing in front of a wall and press the tip of my nose into the wall, that is the anterior part of my body. If I turn around and touch my butt to the wall, the posterior aspect of my body is touching the wall. That's also why posterior is a slang term for the butt, though outdated. These concepts are similarly comparative, the forehead is anterior to the back of the head and the spine is posterior to the heart. Again, many anatomical structures are named with these terms, for example in dentistry we pay very close attention to the anterior superior alveolar nerve and the posterior superior alveolar nerve. Both provide sensory information from the maxillary teeth (the ones on top), with, as you guessed, the ASAN doing the teeth in front of the PSAN.
Other terms: Commonly used are also proximal and distal. Commonly associated with the extremities, the arms and legs, proximal means closer to the body while distal means away from. For example, the fingers are distal to the shoulder, or the shoulder is proximal to the hand. Dorsal means the same thing as posterior and ventral means the same thing as anterior. Dors- in Latin means pertaining to the back, think of a fish having a dorsal fin, while ventral comes from the Latin ventr- meaning pertaining to the stomach. Rostral and Caudal are opposing terms that are more antiquated and used less frequently. Rostral is synonymous with superior and caudal is the same as inferior, i.e., the feet are caudal to the knees, the head is rostral to the heart.
Superficial and Deep are terms associated with a relation to the skin. For example look at your hand and arm. You will probably see veins, but not pulsing red arteries. That is because veins lie superficial to arteries (generally). Evolutionarily that makes sense, if a vein gets cut, you might bleed some but will probably be okay, but if your aorta off the heart was right under the skin of your chest and you got a small cut, you might have serious problems.
Try to get comfortable using these terms and thinking spatially in these terms. I find that imaging some of the pictures above and rotating them in my mind when I am trying to figure out a test question is very helpful, it might work for you too. These are just the basics and there are more terms that are associated with specific areas, radial and ulnar in the forearm for example, which I will deal with in more detail when we get there.
Lastly, bookmark this page of Latin terms, it pays big time to just browse it or connect the dots when learning new things.
http://en.wikipedia.org/wiki/List_of_medical_roots,_suffixes_and_prefixes
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