Lesson 2 Anatomical Terminology

ANATOMICAL TERMINOLOGY

a. As mentioned earlier, you must know the language of a particular field to be successful in it. Each field has specific names for specific structures and functions. Unless you know the names and their meanings, you will have trouble saying what you mean. You will have trouble understanding what others are saying. You will not be able to communicate well.

b. What is a scientific term? It is a word that names or gives special information about a structure or process. Some scientific terms have two or three different parts. These parts are known as a PREFIX, a ROOT (or base), and a SUFFIX. An example is the word subcutaneous.

SUB = below prefix

CUTIS = skin root

SUBCUTANEOUS = below the skin

A second example is the word myocardium.

MYO = muscle prefix

CARDIUM = heart root

MYOCARDIUM = muscular wall of the heart

A third example is the word tonsillitis.

TONSIL = tonsil (a specific organ) root

ITIS = inflammation suffix

TONSILLITIS = an inflammation of the tonsils

THE ANATOMICAL POSITION

The anatomical position is an artificial posture of the human body (see figure 1-2). This position is used as a standard reference throughout the medical profession. We always speak of the parts of the body as if the body were in the anatomical position. This is true regardless of what position the body is actually in. The anatomical position is described as follows:

a. The body stands erect, with heels together.

b. Upper members are along the sides, with the palms of the hands facing forward.

c. The head faces forward.  (click over the picture to enlarge)

PLANES OF THE BODY

See figure 1-3 for the imaginary planes used to describe the body.

a. Sagittal planes are vertical planes that pass through the body from front to back. The median or midsagittal plane is the vertical plane that divides the body into right and left halves.

b. Horizontal (transverse) planes are parallel to the floor. They are perpendicular to both the sagittal and frontal planes.

c. Frontal (coronal) planes are vertical planes which pass through the body from side to side. They are perpendicular to the sagittal plane.       

 

DIRECTIONS

a. Superior, Inferior. Superior means above. Inferior means below.

b. Anterior, Posterior.

(1) Anterior (or ventral) refers to the front of the body.

(2) Posterior (or dorsal) refers to the back of the body.

c. Medial, Lateral. Medial means toward or nearer the midline of the body. Lateral means away from the midline or toward the side of the body.

d. Superficial, Deep. Superficial means closer to the surface of the body.  Deep means toward the center of the body or body part.

e. Proximal, Distal. Proximal and distal are terms applied specifically to the limbs. Proximal means nearer to the shoulder joint or the hip joint. Distal means further away from the shoulder joint or the hip joint. Sometimes proximal and distal are used to identify the "beginning" and "end" of the gut tract--that portion closer to the stomach being proximal while that further away being distal.

NAMES

a. Names are chosen to describe the structure or process as much as possible. An international nomenclature was adopted for anatomy in Paris in 1955. It does not use the names of people for structures. (The single exception is the Achilles tendon at the back of the foot and ankle.)

b. Names are chosen to identify structures properly. Names identify structures according to shape, size, color, function, and/or location. Some examples are:

TRAPEZIUS MUSCLE

TRAPEZIUS = trapezoid (shape)

ADDUCTOR MAGNUS MUSCLE

AD = toward

DUCT = to carry (function)

MAGNUS = very large (size)

ERYTHROCYTE

ERYTHRO = red (color)

CYTE = cell

BICEPS BRACHII MUSCLE

BI = two

CEPS = head (shape)

BRACHII = of the arm (location)