Lesson

Medical terms are composed of parts. These parts can be easily learned and recognized through a systematic process. The usual approach to learning medical terms is to examine body system roots, combining forms, prefixes, and suffixes. Each body system has its own set of specialized word parts and words to describe the general structure of that system, along with its anatomy and physiology and the pathological conditions that affect the system. Depending upon how they are classified, there are 11 to 12 body systems. In this course, we will look at 12 body systems.

The first step in the process is to learn the component parts, what they mean, and how they combine to form words.

Word parts are key in learning medical terminology. There are five basic types of word parts used to create complex medical terms:

• Word roots
• Combining vowels
• Combining forms
• Suffixes
• Prefixes

Word roots usually, but not always, indicate the part of the body involved. Some examples include:

• cardi = heart
• gastr = stomach
• neur = nerve

Combining vowels are used to join parts. Combining vowels are usually the letter "o." Think of the combining vowel as a bridge that links roots to other roots and roots to suffixes.

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Combining forms are created by adding a vowel (usually the letter "o") to the end of a word root and are designated by placing a diagonal, or slash, after the last letter of the root and then adding the combining vowel. The combining vowel is used when connecting word roots or when the word root is joined to a suffix that begins with a consonant. The combining vowel is dropped if the first letter of the suffix is a vowel. Some examples include:

• cardi/o = heart
• gastr/o = stomach
• neur/o = nerve

Suffixes usually, but not always, indicate the procedure, condition, disorder, or disease. Some examples include:

• cardio megaly
  
• gastralgia
  
• neuritis
  

Prefixes usually, but not always, indicate location, time, number, or status. Some examples include:

• pericardium
• epigastric
• polyneuritis

Anatomically, terms can be used that define the location and function of body parts, which include the following:

• Body planes
• Body directions
• Body cavities
• Structural units

Cytology is concerned with the structure and function of cells, including chromosomes, DNA, and genetics. Cells may be described as the basic building blocks of the human body. They have many different shapes and vary in size and function. Histology is the study of tissues. Tissues are groups of cells that perform the same specialized function and include epithelial tissue, which forms the outer layer of the body's surface and forms the lining of hollow organs, connective tissue, which supports, connects, and binds other tissues together, and muscle tissue, which has the ability to contract and expand.

In order of increasing levels of organization, the functional units of the human body are:

• cells
• tissues
• organs
• organ systems
• organism (you!)