Body Positions

When describing human anatomy, it is important to have a fixed reference point to eliminate confusion. Words such as left and right can be subjective, because it is unclear as to whether the person's left or the doctor's left is being described. The anatomical position eliminates this confusion by serving as the standardized position to which all things are referred. The anatomical position uses the person's perspective and not the doctor's so that the right hand is on the right side of the body and the left hand is on the left. In this position, the body is standing up straight with the face forward. The arms are at each side with the palms of the hands also facing forward. Directional terms such as anterior and posterior, medial and lateral, abduction and adduction, and so on apply to the body when it is in the anatomical position. The following descriptive terms may be used when speaking of body positions:

• Prone: when the body is positioned lying face down
• Supine: when the body is positioned lying face up
• Unilateral: referring to one side of the body
• Bilateral: referring to both sides of the body

Many of the words used in the biological and health sciences include a common set of prefixes, suffixes, and root words often derived from Greek and Latin. These compound words allow for a more precise description of the human form that helps to eliminate ambiguity. Prefixes are placed before the root word and can add a variety of meanings to that word, including characteristics such as time, position, amount, and color. Similarly, suffixes placed at the end of the root can clarify specific symptoms, processes, or conditions. Altering any of these components allows for quite varied expression in anatomical terminology. For example, the term periphlebitis, which refers to an inflammation around the veins, uses the prefix peri-, meaning "around," and the suffix -itis, meaning "inflammation." The root word phleb is derived from the Greek phlebo, meaning "vein." In this way, seemingly complex terms can be understood by simply breaking them down into their component parts.