1 Word Parts and Rules

Word Parts

Medical terms are built from word parts. Those word parts are prefix, word root, suffix, and combining form vowel. When a word root is combined with a combining form vowel the word part is referred to as a combining form.

Identifying Word Parts in Medical Terms

By the end of this book, you will have identified hundreds of word parts within medical terms. Let’s start with some common medical terms that many non-medically trained people may be familiar with.

Language Review

Before we begin analyzing the rules let’s complete a short language review that will assist with pronunciation and spelling.

Language Rules

Language rules are a good place to start when building a medical terminology foundation. Many medical terms are built from word parts and can be translated literally. At first, literal translations sound awkward. Once you build a medical vocabulary and become proficient at using it, the awkwardness will slip away. For example, suffixes will no longer be stated and will be assumed. The definition of intravenous then becomes within the vein.

Since you are at the beginning of building your medical terminology foundation, stay literal when applicable. It should be noted that as with all language rules there are always exceptions and we refer to those as rebels.

Language Rules for Building Medical Terms

1. When combining two combining forms, you keep the combining form vowel.
2. When combining a combining form with a suffix that begins with a consonant, you keep the combining form vowel.

   Examples

   Gastr/o/enter/o/logy – The study of the stomach and the intestines

   • Following rule 1, when we join combining form gastr/o (meaning stomach) with the combining form enter/o (meaning intestines) we keep the combining form vowel o.
   • Following rule 2, when we join the combining form enter/o (meaning intestines) with the suffix -logy (that starts with a suffix and means the study of) we keep the combining form vowel o.

    

3. When combining a combining form with a suffix that begins with a vowel, you drop the combining form vowel.
4. A prefix goes at the beginning of the word and no combining form vowel is used.

   Examples

   Intra/ven/ous – Pertaining to within the vein

   • Following rule 3, notice that when combining the combining form ven/o (meaning vein) with the suffix -ous ( that starts with a vowel and means pertaining to) we drop the combining form vowel o.
   • Following rule 4, the prefix intra- (meaning within) is at the beginning of the medical term with no combining form vowel used.

    

5. When defining a medical word, start with the suffix first and then work left to right stating the word parts. You may need to add filler words. As long as the filler word does not change the meaning of the word you may use it for the purpose of building a medical vocabulary. Once you start to apply the word in the context of a sentence it will be easier to decide which filler word(s) to choose.

   Examples

   Intra/ven/ous – Pertaining to within the vein or Pertaining to within a vein.

   • Following rule 5, notice that I start with the suffix -ous (that means pertaining to) then we work left to right starting with the prefix Intra- (meaning within) and the combining form ven/o (meaning vein).
   • Notice that we have used two different definitions that mean the same thing.
   • In these examples we do not have the context of a full sentence. For the purpose of building a medical terminology foundation either definition is accepted.