Ch.1 Introduction to Medical Terminology

Medical Term Components

Medical terminology is built from specific word parts, each contributing to the overall meaning of the term. Understanding these components is essential for interpreting and constructing medical terms.

• Constructed Terms: Medical terms formed from multiple word parts or components.

• Eponyms: Terms not built from word parts but derived from people's names (e.g., Alzheimer disease).

• Word Root: The core part of the term that contains the fundamental meaning (e.g., cardi for heart).

• Combining Vowel: Usually 'o', used to connect word roots or a word root and a suffix (e.g., cardi/o).

• Prefix: Added to the beginning of a word root to modify its meaning (e.g., hypo- means below).

• Suffix: Added to the end of a word root to modify its meaning, often indicating a condition, disease, procedure, or action (e.g., -itis means inflammation).

Example: Electrocardiogram = electro- (electricity) + cardi/o (heart) + -gram (record or image): a record of the heart's electrical activity.

Defining Medical Terms

To define a medical term, follow these steps:

1. First, define the suffix (condition, disease, procedure, etc.).

2. Then, define the prefix (direction, position, quantity, etc.).

3. Finally, define the word root (core meaning).

Example: Hypoglycemia = hypo- (below) + glyc (sugar) + -emia (blood condition): a condition of low blood sugar.

Forming Terms from Word Parts

Medical terms are constructed by combining word parts in a specific order:

1. Determine if a combining vowel is necessary (use it when the suffix starts with a consonant or when joining two roots).

2. Add the suffix to the end of the word root.

3. Add the prefix to the beginning of the word root.

4. Interpret the meaning of the term.

Example: Antipathogenic = anti- (against) + path/o (disease) + -genic (producing): producing against disease.

Word Roots and Combining Forms

Word roots provide the core meaning of medical terms. Combining forms are word roots plus a combining vowel, used to connect to suffixes or other roots.

Prefixes

Prefixes are added to the beginning of medical terms to modify their meaning, often indicating number, amount, quality, or position.

• Number/Amount Prefixes: e.g., poly- (many), uni- (one), bi- (two), semi-/hemi- (half), nulli- (none).

• Quality Prefixes: e.g., brady- (slow), dys- (difficult, bad), eu- (good), heter- (different), mal- (bad), mega-/megal- (very large), neo- (new), tachy- (fast), ultra- (beyond normal).

• Position/Placement Prefixes: e.g., ante-/pre- (in front of), dorsi-/dorso- (behind), infer-/infra-/hypo- (below), circum- (around), peri- (surrounding), ep-/epi- (over, above), ab- (away from), ad- (toward), ec- (outside), intra- (within), inter- (between), para- (beside), dia- (through).

Suffixes

Suffixes are added to the end of medical terms to indicate conditions, diseases, procedures, or specialties.

• General Use Suffixes: -blast (immature cell), -cyte (cell), -logy (study of), -therapy (treatment), -thermy (heat).

• Grammatical Suffixes: Used to form nouns, adjectives, or diminutives (e.g., -icle, -ole, -ula, -ule for small or minute).

• Pathological Suffixes: -mania (obsession), -phobia (fear), -edema (swelling), -emesis (vomiting), -asthenia (weakness), -algia (pain), -itis (inflammation), -lepsy (seizure), -malacia (softening), -megaly (enlargement), -oma (tumor), -pathy (disease), -penia (deficiency), -phasia (speech), -plegia (paralysis), -rrhage (bursting forth), -rrhea (flow/discharge), -rrhexis (rupture).

• Diagnostic & Surgical Suffixes: -tomy (cutting into), -ectomy (removal), -stomy (new opening), -centesis (puncture to remove fluid), -desis (binding), -rrhaphy (suturing), -graph (recording instrument), -graphy (recording process), -meter (measuring instrument), -metry (measuring process), -scope (viewing instrument), -scopy (viewing process).

Plural Endings

Many medical terms have singular and plural forms derived from Latin or Greek. Understanding these endings is important for accurate communication.

Example: The plural of metastasis is metastases.

Practice and Application

• Interpretation: Practice breaking down and defining medical terms using the rules above.

• Construction: Practice constructing terms from given word parts and interpreting their meanings.

• Pluralization: Practice converting singular medical terms to their correct plural forms.

Example: Perinephrectomy = peri- (around) + nephr (kidney) + -ectomy (removal): surgical removal of tissue around the kidney.

Example: Polyneuropathy = poly- (many) + neur/o (nerve) + -pathy (disease): disease affecting many nerves.