Concept: Medical Term Components

Constructed Terms: Word Parts in Medical Terminology

Medical terms are often constructed from four basic word parts or components. Understanding these components is essential for interpreting and forming medical terms.

• Word root: The central meaning of the term, usually indicates a part of the body.

• Combining vowel: Usually 'o', used to connect word parts for easier pronunciation.

• Prefix: Added to the beginning of a word root to modify its meaning, often indicating location, time, number, or status.

• Suffix: Added to the end of a word root to indicate procedure, condition, disorder, or disease.

Example: Electro-cardio-gram

• Electro-: electricity (prefix)

• cardi/o: heart (word root + combining vowel)

• -gram: record (suffix)

Additional info: Eponyms are terms not built from word parts but derived from people's names (e.g., Lou Gehrig's disease).

Components of Medical Terms

Word Root, Prefix, Suffix, and Combining Vowel

Each component plays a specific role in the construction and meaning of medical terms.

• Word root: Foundation of the term, usually indicates part of the body.

• Prefix: Modifies the meaning, often location, time, number, or status.

• Suffix: Indicates procedure, condition, disorder, or disease.

• Combining vowel: Usually 'o', used to connect word parts for easier pronunciation.

Examples:

• Electroencephalogram: electro- (electricity) + encephal/o (brain) + -gram (record)

• Polymyalgia: poly- (many) + my (muscle) + -algia (pain)

• Endocarditis: endo- (within) + card (heart) + -itis (inflammation)

• Blepharoplasty: blephar/o (eyelid) + -plasty (surgical repair)

Table: Matching Word Parts to Definitions

Defining Medical Terms

Steps to Define a Medical Term

When defining a medical term, follow these steps:

1. Start with the suffix – indicates condition, disease, procedure, etc.

2. Then the prefix – indicates location, number, quantity, etc.

3. Finally, the word root(s) – core meaning of the term.

Example: Hypo-glyc-emia

• Hypo-: below, deficient

• glyc-: sugar

• -emia: condition of the blood

Meaning: a condition of low sugar in the blood.

Interpreting Medical Terms

Examples of Term Interpretation

• Polymyopathy: poly- (many) + my/o (muscle) + -pathy (disease) = disease of many muscles

• Perinectomy: peri- (around) + -ectomy (surgical removal) = surgical removal around the kidney

Forming Terms from Word Parts

Steps to Construct Medical Terms

By combining the four components, it is possible to create numerous medical terms. Follow these steps:

1. Step 1: Select word parts (prefix, root, suffix, combining vowel) from the given options.

2. Step 2: Determine if a combining vowel is necessary. Use when suffix starts with a consonant; do not use when suffix starts with a vowel.

3. Step 3: Add prefix to beginning of word root, add suffix to end.

4. Step 4: Interpret the meaning.

Examples:

• gastro- (stomach) + -algia (pain) = gastralgia (pain in the stomach)

• epi- (above) + gastr/o (stomach) + -ic (pertaining to) = epigastric (pertaining to above the stomach)

Additional info: Combining vowels are most commonly 'o', but sometimes 'i' or 'a' are used.