Etymology
With particular thanks to Jack Lyons, MD
Anatomy is the science of the morphology and structure of organisms. The word is derived from the Greek ana-, up; and tome-, a cutting. As might be suspected from its etymology, anatomy depends heavily on dissection. In fact, the words anatomy and dissection, from the Greek and Latin respectively, have virtually identical meanings. Despite this root similarity, anatomy and dissection have evolved very differently. On the one hand, anatomy has become a broad discipline that examines function as well as form and embraces elements of several related fields of study. By contrast, dissection remains but a useful technique of anatomical science.
The ancient Greeks were the first to systematically study the field of medicine (including anatomy) and to develop a suitable vocabulary. The Romans continued this study, usually adopting the Greek terms which they modified as necessary to fit their alphabet and grammar. Latin then continued as the language of science, the law, and the Church throughout Western Europe until the eighteenth century. As a result, the vast majority of the vocabulary of scientific medicine in use today derives directly from these Latin roots. Other significant word sources include Arabic and the Romance languages (whence terms of Latin origin sometimes reemerge in the guise of French, Italian or Spanish words). The German, Scandinavian and other languages have made lesser contributions to the medical lexicon.
Many anatomical terms have both Latin and Greek equivalents (see Table 1 ), although some of these are used in English only as roots. Thus the tongue is lingua (L.) and glossa (Gk), and these are the basis of such terms as lingual artery and glossopharyngeal nerve. In the case of English, Anglo-Saxon may provide a third form, particularly in everyday words such as hand and foot. A good instance is book (Old Saxon), liber (L., as in library), biblos (Gk, as in bible). The following examples illustrate this trilingual system in anatomy and show some English derivatives from Latin and Greek.
Most terms used in biology and medicine are derived from Latin or Greek (the latter usually converted into Latin forms). As a result, particular attention has to be paid to the formation of the genitive (possessive) case and to plural forms. Latin nouns are divided into five classes (termed declensions), and their cases vary, as shown by the following plurals: papilla, papillae; nucleus, nuclei, but ligamentum, ligamenta; os, ossa, but dens, dentes; sinus, sinus, but cornu, cornua. Examples of genitive singular are seen in levator scapulae, arrector pili, semispinalis capitis, and articulatio genus. Instances of genitive plural are levatores costarum, extensor digitorum, vincula tendinum, and confluens sinuum. Moreover, adjectives must agree with their nouns: thus, ramus communicans, rami communicantes; and foramen ovale, fossa ovalis.
Anatomic terminology is undergoing standardization according to a system known as the Nomina Anatomica (N. A.). The general rules of the system are that there should be one term for each structure and that the term selected should have some informative or descriptive value. Thus, eponyms are excluded. Latin was chosen as the official language but translation to the vernacular is permitted for teaching purposes. Despite the standardization, a large number of nonconforming words remain in use. Some of these are holdovers from older terminology, others are short-cut words used to avoid more complex terms and still others are simply the result of convenient habits. It will be noted that, although many of these Latin forms are used in English, others are not. For example, rectus femoris and lamina terminalis are never translated, whereas plexus brachialis and corpus ossis ilii (body of the ilium) always are. This is a matter of common usage: canalis caroticus and foramen jugulare are always translated, whereas foramen lacerum and dorsum sellae are not. In the case of those that are retained in Latin, it is prudent to consult an appropriate dictionary. In this way it will be found that the plural of diverticulum is diverticula (not -ae); that the plural of meatus remains meatus in Latin or becomes meatuses in English (similarly sinus and fetus); and that the genitive singular of epididymis is (ductus) epididymidis (extra syllable -id-), whereas the (nominative) plural is epididymides. Other examples of Greek plurals are pharynx, pharynges; and ganglion, ganglia.
Like all words, anatomic terms are composed of one or more roots. These may be preceded by prefixes and/or followed by suffixes. Determination of the root meaning will usually establish the main thrust of the term.
Latin is a highly inflected language in which nouns have different endings depending upon their assigned gender and their use in a sentence. Every Latin noun is either masculine, feminine or neuter, but the basis for the choice may not be immediately obvious. The most common endings for Latin nouns when they appear as subjects (the nominative case) are as follows:
| MASCULINE | FEMININE | NEUTER | |
|---|---|---|---|
| SINGULAR | -us |
-a |
-um |
| PLEURAL | -i |
-ae |
-a |
For example, one speaks of a single scalenus muscle, but of several scaleni. Or a patient may have one inflamed diverticulum among many noninflamed diverticula.
In addition, the ending of a noun may change depending on its use in a term. For example, the Latin words for great toe and hammer are hallux and malleus respectively. Hallux malleus is, therefore, a hammertoe of the big toe. But, the long muscle that extends the great toe is called extensor hallucis longus or the long extensor of the big toe. Here the word for great toe is in a form that indicates possession (the genitive case).
Continuing in this vein, digitus is the Latin word for finger. And extensor digiti minimi is the extensor muscle of the least, or minimal, finger. Here the singular form of the genitive case of the word digitus is used to indicate that the muscle extends only one finger. But there is also an extensor digitorum longus that is the long extensor of the fingers. The ending -orum (genitive plural) indicates that the muscle is the extensor of more than one finger. Be aware that there are many variations on this basic theme and that other less common noun declensions take different endings.
Like all words, anatomic terms are composed of one or more roots. These may be preceded by prefixes and/or followed by suffixes. Determination of the root meaning will usually establish the main thrust of the term. Many roots, prefixes and suffixes occur repeatedly in anatomical terminology. Spending a little time to become familiar with some of the more common ones, as in the following list, will enhance your understanding of many of the terms encountered in the course and, hopefully, may add an unexpected bit of pleasure to mastering them (see Table 2).
Each body region has its own set of anatomical terms. There are separate discussions of each of these body regions provided. Please see the following for further explanation of specific terms: chest wall; thoracic viscera; abdominal wall; abdominal viscera; pelvis and perineum; soulder and arm; forearm, wrist and hand; lower limb; neck; head.
A particularly valuable and interesting source of information on anatomical terminology is H. A. Skinner, The Origin of Medical Terms, 2nd ed., Williams & Wilkins, Baltimore, 1961. Assuredly the most concise account of this subject (only 32 pages!) is to be found in P. H. Yancey, Introduction to Biological Latin and Greek, 5th ed., Spring Hill College Press, Mobile, Alabama, 1959. Although these books are no longer available for purchase, they may be found in libraries.