Basic Elements of a Medical Word

BASIC ELEMENTS OF A MEDICAL WORD Objectives Upon completion of this module, you will be able to: • 1. Identify the four word elements used to build medical words. 2. Divide medical words into their component parts. 3. Apply the basic rules to define and build medical words. 4. Locate the pronunciation guidelines chart and interpret pronunciation marks. 5. Pronounce medical terms presented in this chapter. 6. Demonstrate your knowledge of this chapter by completing the learning activities. MEDICAL WORD ELEMENTS The language of medicine is a specialized vocabulary used by health care practitioners. Many current medical word elements originated as early as the 1st century B.C., when Hippocrates practiced medicine. With advancements in medicine, new terms have evolved to reflect these innovations. For example, radiographic terms, such as magnetic resonance imaging (MRI) and ultrasound (US), are now used to describe current diagnostic procedures. A medical word consists of some or all of the following elements: word root, combining form, suffix, and prefix. How you combine these elements, and whether all or some of them are present in a medical term, determines the meaning of a word. The purpose of this chapter is to help you identify these elements in order to construct medical terms correctly. WORD ROOTS A word root is the foundation of a medical term and contains its primary meaning. All medical terms have at least one word root. Most word roots are derived from Greek or Latin language. Thus, two different roots may have the same meaning. For example, the Greek word dermatos and the Latin word cutane both refer to the skin. As a general rule, Greek roots are used to build words that describe a disease, condition, treatment, or diagnosis. Latin roots are used to build words that describe anatomical structures. Consequently, the Greek root dermat is used primarily in terms that describe a disease, condition, treatment, or diagnosis of the skin; the Latin root cutane is used primarily to describe an anatomical structure. (See Table 1-1.) Table 1-1 Examples of Word Roots This table list examples of word roots as well as their phonetic pronunciations. Begin learning pronunciations as you review the information below. English Term Greek or Latin Term* Word Root Word Analysis skin dermatos (Gr) dermat dermat/itis (de!r-ma!-T"I-t!ıs): inflamma- tion of the skin A term that describes a skin disease cutis (L) cutane cutane/ous (su!b-ku"-TA"-ne"-u!s): pertaining to the skin A term that describes an anatomical structure kidney nephros(Gr) nephr nephr/oma(ne!-FRO"-ma!):tumorof the kidney A term that describes a kidney disease mouth renes (L) ren ren/al (RE"-na!l): pertains to the kidney A term that describes an anatomical structure stomatos(Gr) stomat stomat/itis(sto"-ma!-T"I-t!ıs):inflam- mation of the mouth A term that describes any inflammatory condition of the mouth oris (L) or or/al (OR-a!l): pertaining to the mouth A term that describes an anatomical structure Combining Forms A combining form is created when a word root is combined with a vowel. The vowel, known as a combining vowel, is usually an o, but sometimes it is an i. The combining vowel has no meaning of its own, but enables two word elements to be connected. Like the word root, the combining form is the basic foundation to which other word elements are added to build a complete medical word. In this text, a combining form will be listed as word root/vowel (such as gastr/o), as illustrated in Table 1-2. Suffixes A suffix is a word element placed at the end of a word that changes the meaning of the word. In the terms tonsill/itis, and tonsill/ectomy, the suffixes are -itis (inflammation) and -ectomy (excision, removal). Changing the suffix changes the meaning of the word. In medical terminology, a suffix usually describes a pathology (disease or abnormality), symptom, surgical or diagnostic procedure, or part of speech. Many suffixes are derived from Greek or Latin words. (See Table 1-3.) Table 1-2 Examples of Combining Forms This table illustrates how word roots and vowels create combining forms. Learning combining forms rather than word roots makes pronunciation a little easier because of the terminal vowel. For example, in the table below, the word roots gastr and nephr are difficult to pronounce, whereas their combining forms gastr/o and nephr/o are easier to pronounce. Word Root + Vowel = Combining Form Meaning erythr/ + O = ︎#erythr/o red gastr/ + O = ︎#gastr/o stomach hepat/ + O = ︎#hepat/o liver immun/ + O = ︎#immun/o immune, immunity, safe nephr/ + O = ︎#nephr/o kidney oste/ + O = oste/o bone Prefixes A prefix is a word element attached to the beginning of a word or word root. However, not all medical terms have a prefix. Adding or changing a prefix changes the meaning of the word. The prefix usually indicates a number, time, position, direction, or negation. Many of the same prefixes used in medical terminology are also used in English language. (See Table 1-4.) Basic Guidelines Defining and building medical words are crucial skills in mastering medical terminology. Following the basic guidelines for each will help you develop these skills. Defining Medical Words Here are three basic steps for defining medical words using gastroenteritis as an example. 1. Define the suffix, or last part of the word. In this case, the suffix -itis, which means inflammation. 2. Define the first part of the word (which may be a word root, combining form, or prefix). In this case, the combining form gastr/o means stomach. 3. Define the middle parts of the word. In this case, the word root enter means intestine. When you analyze gastroenteritis following the three previous rules, the meaning is: 1. inflammation (of ) 2. 2. stomach (and) 3. 3. intestine. Thus, the meaning of gastroenteritis is inflammation (of) stomach (and) intestine. Table 1-5 on page 4 further illustrates this process. Building Medical Words There are three basic rules for building medical words. Rule #1: A word root links a suffix that begins with a vowel. Rule #2: A combining form (root ︎o) links a suffix that begins with a consonant. Rule #3 : A combining form links a root to another root to form a compound word. This rule holds true even if the next root begins with a vowel, as in osteoarthritis. Keep in mind that the rules for linking multiple roots to each other are slightly different from the rules for linking roots and combining forms to suffixes. Special Sounds Here are rules regarding certain letter combinations and special sounds attributed to letters based on their placement in a medical word: •For ae and oe, only the second vowel is pronounced. Examples are bursae, pleurae, and roentgen. •The soft sound of s and j are given to c and g, respectively, before e, i, and y in words of Greek or Latin origin. Examples are cerebrum, circumcision, cycle, gel, gingivitis, giant, and gyrate. •Before other letters, c and g have a hard sound. Examples are cardiac, cast, gastric, and gonad. •The letters ch are sometimes pronounced like k. Examples are cholesterol, cholera, and cholemia. •When pn appears at the beginning of a word, p is silent and only n is pronounced. Examples are pneumonia and pneumotoxin. •When pn appears in the middle of a word, p and n are pronounced. Examples are orthopnea and hyperpnea. •When ps appears at the beginning of a word, p is silent and only s is pronounced. Examples are psychology and psychosis. •When forming the final letter(s) of a word, e and es are commonly pronounced as separate syllables. Examples are syncope, systole, and nares. •When i appears at the end of a word (to form a plural), it is pronounced eye. Examples are bronchi, fungi, and nuclei. •All other vowels and consonants have normal English sounds. Pronunciation Marks Diacritical marks and capitalization are used to aid pronunciations throughout the text. Diacritical marks are used to show vowel sounds, and capitalization is used to show emphasis. Diacritical marks are symbols placed above or under vowels. They show vowel sounds. In this text, only two diacritical marks are used: the macron ( !) and the breve ( "). The macron indicates the long sound of vowels, as in: a ! in rate e ! in rebirth !ı in isle o ! in over u ! in unite The breve indicates the short sound of vowels, as in: a " in apple e " in ever "ı in it o " in not u " in cut Capitalization is used to indicate primary accent. For example, the pronunciation LE " T-te "r indicates that emphasis should be placed on the first syllable when pronouncing the word letter.