This guide introduces the foundational knowledge necessary for understanding medical terminology. It provides an overview of the different types of medical word parts and a reference document of the most commonly used medical word parts.
When you combine a suffix to a word root, you MUST ALWAYS use the combining form of the word root. There are two scenarios to consider when combining a suffix with a word root combining form:
How to Combine Suffixes to The Word Root Combining Form:
1. When a suffix starts with a consonant, you keep the combining form vowel "o" on the word root.
2. When the suffix starts with a vowel, you drop the combining form vowel "o" on the word root.
Let's use the word root combining form " dermat/o " (refers to the skin) with a suffix that begins with a consonant, " -logy " (refers to study of), and a suffix that begins with a vowel, " -itis " (refers to inflammation).
Dermato logy (suffix starts with consonant so we keep the combining form vowel "o" on the word root)
Derm at itis (suffix starts with a vowel so we drop the combining form vowel "o" on the word root)
Adding a prefix to the combining form of a word root is very simple. Just add the prefix to the combining form of the word root. There are NO rules or modifications associated with if the word root begins with a consonant or vowel.
For example, if you have the following prefixes:
We can easily add them to the combing forms of word roots:
A common practice when combining two word roots together is to keep the combining form vowel ("o") on the word root before the next word root. For example:
Notice how the combining vowel "o" on "oste/o" is kept when it is combined with the combining form of arthr/o, but the combing vowel "o" from arthr/o is dropped when combined with the suffix "-itis" .
How about this word: Chole docho lith iasis
Word Root/Combining Form: chol/e = bile
Word Root/Combining Form: doch/o = duct
Word Root/Combining Form: lith/o = stone
Suffix: - iasis = condition of
This term literally means a condition of the stones in the bile duct.
*Notice we keep the combining form vowel ("e") with chol/e and it is kept when combining chol/e with doch/o. The combining form vowel ("o") on doch/o is kept when combining it with lith/o. Regarding the combining form vowel with lith/o, we are combining it with a suffix, so the rules associated with adding a suffix to a word root combining form apply. Since the suffix begins with a vowel, we drop the combining form vowel on lith/o.
How about this word: Esophago gastro duodeno scopy
This term literally means visual inspection (with a camera) of the esophagus, stomach, and duodenum of the small intestine.
*Notice we keep the combining form vowel ("o") between esophag/o and gastr/o and duoden/o. Regarding the combining form vowel with duoden/o, we are combining it with a suffix, so the rules associated with adding a suffix to a word root combining form apply. Since the suffix begins with a consonant, we keep the combining form vowel ("o") on duoden/o.
