Anatomical Directional Terms and Body Planes

Anatomical Directional Terms and Body Planes Anatomical directional terms are like the directions on a compass rose of a map. Like the directions, North, South, East and West, they can be used to describe the locations of structures in relation to other structures or locations in the body. This is particularly useful when studying anatomy as it provides a common method of communication that helps to avoid confusion when identifying structures. Also as with a compass rose, each directional term often has a counterpart with converse or opposite meaning. These terms are very useful when describing the locations of structures to be studied in dissections. Anatomical directional terms can also be applied to the planes of the body. Body planes are used to describe specific sections or regions of the body. Below are examples of some commonly used anatomical directional terms and planes of the body. Anatomical Directional Terms Anterior: In front of, frontPosterior: After, behind, following, toward the rearDistal: Away from, farther from the originProximal: Near, closer to the originDorsal: Near the upper surface, toward the backVentral: Toward the bottom, toward the bellySuperior: Above, overInferior: Below, underLateral: Toward the side, away from the mid-lineMedial: Toward the mid-line, middle, away from the sideRostral: Toward the frontCaudal: Toward the back, toward the tailBilateral: Involving both sides of the bodyUnilateral: Involving one side of the bodyIpsilateral: On the same side of the bodyContralateral: On opposite sides of the bodyParietal: Relating to a body cavity wallVisceral: Relating to organs within body cavitiesAxial: Around a central axisIntermediate: Between two structures Anatomical Body Planes Imagine a person standing in an upright position. Now imagine dissecting this person with imaginary vertical and horizontal planes. This is the best way to describe anatomical planes. Anatomical planes can be used to describe any body part or an entire body. (View a detailed body plane image.) Lateral Plane or Sagittal Plane: Imagine a vertical plane that runs through your body from front to back or back to front. This plane divides the body into right and left regions. Median or Midsagittal Plane: Sagittal plane that divides the body into equal right and left regions.Parasagittal Plane: Sagittal plane that divides the body into unequal right and left regions. Frontal Plane or Coronal Plane: Imagine a vertical plane that runs through the center of your body from side to side. This plane divides the body into front (anterior) and back (posterior) regions. Transverse Plane: Imagine a horizontal plane that runs through the midsection of your body. This plane divides the body into upper (superior) and lower (inferior) regions. Anatomical Terms: Examples Some anatomical structures contain anatomical terms in their names that help identify their position in relation to other body structures or divisions within the same structure. Some examples include the anterior and posterior pituitary, superior and inferior venae cavae, the median cerebral artery, and the axial skeleton. Affixes (word parts that are attached to base words) are also useful in describing the position of anatomical structures. These prefixes and suffixes give us hints about the locations of body structures. For example, the prefix (para-) means near or within. The parathyroid glands are located on the posterior side of the thyroid. The prefix epi- means upper or outermost. The epidermis is the outermost skin layer. The prefix (ad-) means near, next to, or toward. The adrenal glands are located atop the kidneys. Anatomical Terms: Resources Understanding anatomical directional terms and body planes will make it easier to study anatomy. It will help you to be able to visualize positional and spatial locations of structures and navigate directionally from one area to another. Another strategy that can be employed to help you visualize anatomical structures and their positions is to use study aids such as anatomy coloring books and flashcards. It may seem a bit juvenile, but coloring books and review cards actually help you to visually comprehend the information.