med terms tutorial

EXAMPLE

while <expression>:
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before you start

In this class, you will see many examples of how word parts combine to make words followed by brief definitions. These definitions emphasize how the meanings of the word parts combine to make the word. For more detailed definitions, please check the glossary. Don’t forget to continue to keep track of terms for the Unit 3 Touchstone Task assignment.

1. Root Words and Combining Forms

You have learned about root words and combining forms before. Remember, a root word is the foundation of a medical term that provides its core meaning. A combining form is a root word plus a combining vowel (usually "o"). Combining forms are used to make pronunciation easier. They are used to combine roots with suffixes or other roots.

Remember that all medical terms have at least one word root.

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Word roots commonly specify:

• A body part or organ (such as cardi- for heart, nephr- for kidney).
• A function or action (such as therm- for heat, tox- for poison).
• A disease or condition (such as path- for disease, carcin- for cancer).

1a. Rules

There are general rules for using root words and combing forms in word formation. For example, root words must be combined with suffixes or other roots to form complete terms. Do not use a root word by itself.

There are some other rules that you learned in an earlier lesson. Let’s look at them again with examples.

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1. When connecting a word root and a suffix, a combining vowel is used if the suffix DOES NOT begin with a vowel.

Arthr/o + -itis → Arthritis (inflammation of a joint)
Arthr/o + -plasty → Arthroplasty (surgical repair of a joint)

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2. When connecting a word root and a suffix, a combining vowel is usually NOT USED if the suffix begins with a vowel.

Append + -ectomy → Appendectomy (removal of the appendix; NOT appendeoectomy)
Cardi + -ac → Cardiac (Related to the heart; NOT cardioac)
Path + -ology → Pathology (Study of disease, example of disease, medical specialty; NOT pathoology)

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3. Combining vowels are typically used when joining two root words.

Oste/o + arthr/o + -itis → Osteoarthritis (inflammation of the bones and joints).
Gastr/o + enter/o + -logy → Gastroenterology

However, a few exceptions exist. This happens if dropping the second combining vowel improves pronunciation.

EXAMPLE

Hyster/o + salping/o + -gram → Hysterosalpingogram (X-ray of the uterus and fallopian tubes).

1b. Examples Using Rules

Using the rules above, you can construct and break down a wide variety of medical terms that include combining forms.

IN CONTEXT

Here are some examples of complex words that can be broken down into parts.

• Electrocardiogram: Electr/o (electricity) + cardi/o (heart) + -gram (record) → Record of the heart’s electrical activity.
• Neuropathy: Neur/o (nerve) + -pathy (disease) → Nerve disease.
• Gastroesophageal: Gastr/o (stomach) + esophag/o (esophagus) + -eal (pertaining to) → Pertaining to the stomach and esophagus.
• Otolaryngology: Ot/o (ear) + laryng/o (throat) + -logy (study of) → Study of the ears, nose, and throat (ENT).

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2. Common Root Words

There are many common root words that are good to know. The table below summarizes examples of some important root words and you will learn many more as you work through this course.

The tables below give examples of root words for body systems and organs:

• Body fluids and substances
• Conditions, functions, or actions
• Directions or positions.

Note that sometimes there is more than one word part with the same or a similar meaning. This is often because the word parts have different origins. In this table, word origins for those terms are specified to illustrate this point.

In this section, we will review examples of root words broken up by categories. The first category is root words for body systems and organs. Some examples are below.

Hepat/o (liver) → Hepatology (study of the liver).
Oste/o (kidney) → Osteology (study of bones).
Pulmon/o (stomach) → Pulmonology (study of the lungs).

2a. Root Words for Body System and Organs

Root word	Meaning	Example	Definition
Cardi/o	Heart	Cardiology	Study of the heart; medical specialty focusing on the heart and cardiovascular system
Nephr/o (from Greek/new Latin); Ren/o (from French/late Latin)	Kidney	Nephritis	Inflammation of the kidney
Hemat/o	Blood	Hematology	Study of blood; medical specialty focusing on blood
Gastr/o	Stomach	Gastroscopy	Visual examination of the stomach (performed using a flexible tube with a camera)
Hepat/o	Liver	Hepatitis	Inflammation of the liver
Oste/o	Bone	Osteoporosis	A condition in which bones become weak and brittle and are at increased risk of breaking/fractures.
Pulmon/o, Pneum/o	Lung	Pulmonology	Study of lungs; medical specialty focusing on lung conditions
Derm/o (New Latin from Greek), Dermat/o (Greek); Cutane/o (French from new Latin)	Skin

Try to answer the question below, then click on the plus sign to see if you answered correctly.

try it

Let’s try an example.

Q: What term means inflammation of the liver? Use the word parts for "pertaining to the liver" and "inflammation."

A: The correct word is hepatitis (hepat/o + -itis).

Next, consider some root words for body fluids and substances. These include essential fluids such as blood, which you are likely to need to reference often. Blood tests and urine tests (like urinalysis) are used very frequently in medical settings, and you also need to use these terms to refer to medical conditions such as hemophila (a bleeding disorder) and hematuria (blood in the urine).

Hemopat/o (liver) → Hepatology (study of the liver).
Lymph/o (lymph) → Lymphedema (build up of lymph fluid).

2b. Root Words for Body Fluids and Substances

Root word	Meaning	Example	Definition
Hem/o (Latin, from Greek), Hemat/o (Latin, from Greek)	Blood	Hemorrhage	Excessive bleeding
Lymph/o (fluid in the lymphatic system)	Lymph	Lymphedema	Swelling due to lymph fluid
Ur/o	Urine	Urology	Study of the urinary system; medical specialty focusing on the urinary system
Chol/e	Bile	Cholecystectomy	Removal of the gall bladder (note that “chol/e” is for bile, “cyst” is for bladder, and “-ectomy” is removal; the gall bladder stores bile).

The next set of word roots are used often as well. For example, a pathologist is a medical specialist who interprets test results. For example, a pathologist may examine slides from biopsies to determine if cancer cells are present. There are different types of pathologists who specialize in different types of tests. A toxicologist studies the effects of toxins (harmful substances/poisons).

Additional examples are below with short definitions (see the glossary for more detailed definitions).

Path/o (disease) → Pathology (study of the disease).
Tox/o (poison/toxin) → Toxicology (study of poisons/toxins).

2c. Root Words for Conditions, Functions, or Actions

Root word	Meaning	Example	Definition
Path/o	Disease	Pathology	Study of disease
Carcin/o	Cancer	Carcinoma	A type of malignant tumor that forms in epithelial tissue (tissue that forms linings, such as the outer layer of skin and the inner lining of the digestive tract)
Tox/o	Poison/toxin	Toxicology	Study of poisons/toxins
Therm/o	Heat	Thermometer	Device for measuring heat

The image below shows a carcinoma. This is a type of malignant cancer that develops in epithelial tissue, meaning tissue that covers and protects (like the outer layer of skin). The image shows a specific type of carcinoma in skin. Note the word parts: carcin (cancer) + oma (growth, often a tumor).

This specific example is squamous cell carcinoma, which is one type of carcinoma. Carcinomas develop in epithelial tissue, which is tissue that forms linings. The image below shows epithelial tissue (the outer layer of skin) above deeper skin and muscle. A carcinoma in the outer layer of skin is growing into deeper layers.

You will also regularly use root words for directions and positions. For example, you may need to specify whether a problem is present on one side (unilateral) or on both sides (bilateral). You will learn much more about body positions, directions, and regions in other lessons.

2d. Root Words for Directions and Positions

Root word	Meaning	Example	Definition
Later/o	Side	Bilateral	Having two sides; referring to both sides; referring to paired organs (one on each side)
Medi/o	Middle	Mediastinum	Area in the center of the chest
Dextr/o	Right	Dextrocardia	Heart positioned to the right
Sinistr/o	Left	Sinistrocular	Left eye dominance

3. Common Mistakes

As you get used to using medical terms, pay particular attention to common mistakes and terms that can be easily confused. With increasing practice, forming words accurately will feel natural and you will get used to noticing errors intuitively.

Here are some examples of common mistakes associated with using combining forms and root words.

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Dropping the combining vowel when it's needed.

Incorrect: Gastrenterology → Correct: Gastroenterology (because “-enterology” starts with a consonant).

Incorrect: Mypathy → Correct: Myopathy (because “pathy” starts with a consonant).

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Adding an unnecessary combining vowel.

Incorrect: Nephroitis → Correct: Nephritis (because "-itis" starts with a vowel).

Incorrect: Arthroitis → Correct: Arthritis (because "-itis" starts with a vowel)

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Confusing similar-looking root words.

Nephr/o (kidney) vs. Neur/o (nerve).
Arthr/o (joint) vs. Ather/o (fatty plaque).