Medical word parts
1Why this matters
You are shadowing a nurse who hands you a chart. It reads: "History of cholecystitis. Now reports gastralgia. Exam shows hepatomegaly." You have never seen those words. By the end of this lesson you will read them as an inflamed gallbladder, stomach pain and an enlarged liver, without looking anything up.
2What this builds on
3Quick check before you start
1. Anatomy is the study of what?
- The body's structures and where they are
- How the body's structures work
- The chemical changes inside cells
Show the answer
Anatomy (ana- = apart, -tomy = cutting) studies structure: shape, size, parts and position. How structures work is physiology.
- Correct: The body's structures and where they are:
- How the body's structures work:
- The chemical changes inside cells:
2. Which organ system includes the kidneys, ureters, urinary bladder and urethra?
- Digestive system
- Urinary system
- Reproductive system
Show the answer
These four organs filter the blood, make urine, store it and carry it out: the urinary system.
- Digestive system:
- Correct: Urinary system:
- Reproductive system:
4How it works, step by step
- You find the suffix at the end of the term.You know what kind of word it is: a condition, a procedure, a field or a description.
- Knowing the kind of word, you look at the front for a prefix.You learn how the meaning is modified: where, how much, how many or how fast.
- With the suffix and prefix set aside, the root or roots are left.You learn which body part or substance the term is about.
- You combine the parts, starting from the suffix.You get the literal meaning, which you then check against the definition.
5Core concepts
6A common mistake
The wrong idea: You decode a medical term by reading its parts from left to right.
What actually happens: Reading left to right gives backwards English: pericarditis becomes "around heart inflamed". Start with the suffix, which says what kind of word it is, then the prefix, then the root: "inflamed, around, the heart", an inflamed sac around the heart.
7Check yourself
Anything you miss goes into your review queue.
1. In the term gastritis, which part is the word root?
- gastr
- -itis
- gastro-
- the letter o
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The word root carries the core meaning. In gastritis that is gastr, "stomach". The ending -itis adds "inflamed".
- Correct: gastr: Correct. gastr is the root; it names the body part, the stomach.
- -itis: -itis is a suffix. It sits at the end and says the term names a condition: something inflamed.
- gastro-: gastr/o is the combining form, the root plus a linking vowel. In gastritis the vowel is dropped because -itis starts with a vowel, so the root alone is present.
- the letter o: Gastritis contains no combining vowel. It is dropped before a suffix that begins with a vowel.
2. A patient's chart says hepatomegaly. What does the term mean?
- Pain in the liver
- An enlarged liver
- Removal of the liver
- An inflamed liver
Show the answer
Read the suffix first: -megaly means enlargement. The root hepat means liver. Hepatomegaly is an enlarged liver.
- Pain in the liver: Pain would be the suffix -algia. The term here ends in -megaly.
- Correct: An enlarged liver: Correct. hepat (liver) + o + megaly (enlargement).
- Removal of the liver: Removal would be the suffix -ectomy, as in hepatectomy.
- An inflamed liver: Inflamed would be the suffix -itis. The term here ends in -megaly.
3. A patient is breathing 8 times a minute, far slower than normal. Which term describes this?
- Bradypnea
- Tachypnea
- Apnea
- Dyspnea
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The prefix brady- means slow and -pnea means breathing. Bradypnea is slow breathing.
- Correct: Bradypnea: Correct. brady- (slow) + -pnea (breathing).
- Tachypnea: tachy- means fast. Tachypnea is fast breathing, the opposite of this patient.
- Apnea: a- means without. Apnea means no breathing at all, and this patient is breathing.
- Dyspnea: dys- means difficult. Dyspnea describes breathing that feels hard, whatever its rate.
4. Which spelling correctly joins gastr/o and -itis?
- Gastroitis
- Gastritis
- Gastrotitis
- Gastrotis
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The combining vowel is dropped before a suffix that begins with a vowel. -itis begins with i, so gastr/o + itis = gastritis.
- Gastroitis: Keeping the o before a vowel breaks the rule and makes an awkward double vowel.
- Correct: Gastritis: Correct. Drop the o before a suffix starting with a vowel.
- Gastrotitis: This keeps the o and adds an extra t between the parts. Neither belongs: the o is dropped, and the suffix is simply -itis.
- Gastrotis: This keeps the o and shortens the suffix to -tis. The suffix stays whole as -itis; it is the o that gets dropped.
5. A student builds the term for an inflamed stomach. One step is wrong. Find it.
- Choose the root for stomach: gastr
- Choose the suffix for inflamed: -itis
- Keep the o, since -itis begins with a vowel
- Join the parts to make a single word
Show the answer
The rule runs the other way: the combining vowel is dropped before a suffix that begins with a vowel. Keeping it would give "gastroitis" instead of gastritis.
- Choose the root for stomach: gastr: This step is right. gastr is the root for stomach.
- Choose the suffix for inflamed: -itis: This step is right. -itis means inflamed.
- Correct: Keep the o, since -itis begins with a vowel: This is the wrong step. Before a suffix that starts with a vowel, the o is dropped.
- Join the parts to make a single word: This step is right. The parts are written as one word: gastritis.
6. Build the term for an enlarged spleen.
- Splenectomy
- Splenalgia
- Splenomegaly
- Splenitis
Show the answer
Root splen (spleen) + combining vowel o + suffix -megaly (enlargement). The vowel stays because -megaly starts with a consonant.
- Splenectomy: -ectomy means removal. A splenectomy removes the spleen.
- Splenalgia: -algia means pain. Splenalgia is pain in the spleen, not enlargement.
- Correct: Splenomegaly: Correct. splen + o + megaly.
- Splenitis: -itis means inflamed. Splenitis is an inflamed spleen, not an enlarged one.
8Summary
Medical terms are built from word parts that keep their meaning wherever they appear. The word root carries the core meaning, usually a body part. A combining form is a root plus a linking vowel, usually o, which is kept between roots and before a suffix that starts with a consonant, and dropped before a suffix that starts with a vowel. A prefix sits in front and modifies the meaning. A suffix sits at the end and tells you what kind of word it is. Decode suffix first, then prefix, then root, and check the literal meaning against the definition.