Anatomic position refers to the position the patient is assumed to be in when talking about the body: standing erect, facing the examiner, with arms at the sides and palms facing forward.
When talking about the patient’s body, the terms “left” and “right” always refer to the patient’s left and right.
The front surface of the body is called the anterior or ventral (lat. venter = belly) surface. The back surface is the posterior or dorsal (lat. dorsum = back) surface.
The body is divided into left and right sides by an imaginary line which runs through the nose and umbilicus (navel) called the midline. Parts of the body that lie close to the midline are called medial, parts that lie far from the midline are called lateral. Directionally, the terms proximal and distal are used to describe a relationship between two body parts. Proximal refers to parts closer to the midline, distal to parts farther from the midline (ex.: the wrist is distal to the elbow, but it is proximal to the fingertips.)
The body direction towards the head is called superior or cranial (lat. cranium = head); towards the feet, inferior or caudal (lat. cauda = tail).
The abdomen is divided into 4 quadrants (it can also be divided into 9 areas, but I’ll spare you that for now..), which are (inventively) called the right upper, right lower, left upper, and left lower quadrants. These are as seen from the patient’s perspective, as stated above. The right upper quadrant contains most of the liver, part of the stomach, the gall bladder, part of the pancreas and a large amount of intestine. The right lower quadrant contains mainly intestine, but also the appendix and part of the bladder. The left lower quadrant contains part of the bladder and intestines, and the left upper quadrant contains the spleen, the pancreas, the stomach and (surprise!) intestines. The kidneys are not, in fact, in the abdominal cavity; they lie in a separate cavity behind the abdomen called the retroperitoneal space.