11 Rules for Changing Singular Terms to Plural Terms
The first article in the medical terminology series discussed the word root, suffixes, prefixes and combining vowel. This article covers 11 rules for changing singular terms to plural terms. While building a medical vocabulary and combining and working with word parts, it is important to understand the rules for pluralization.
In the English language, a plural is formed by simply adding an -s to the singular term. However, there are some exceptions to this rule when a noun ends in -s, -sh, -ch, and some nouns that end in -o. These words are changed to plural by adding an -es. There are some additional rules for English terms but this article will focus on medical terms.
Because medical terms are derived from Latin and Greek terms, they do not always follow the normal rules for pluralization as English terms. These rules hold true in some instances but not all instances. There are always exceptions to these rules. Below are a few rules to remember when changing the singular form of medical terms to the plural form of medical terms.
Medical Terminology Rule #1: Words Ending in -a.
When the singular form of the word ends with -a, keep the -a and add an -e.
Axilla A pyramid-shaped space forming the underside of the shoulder.
Pleura A delicate serous membrane enclosing the lung.
Conjunctiva A mucous membrane lining the inner surface of the eyelid and anterior part of the sclera.
Vertebra One of the bones of the spinal column.
Scapula One of the pairs of large flat triangular bones that forms the dorsal part of the shoulder.
Petechia Numerous tiny purple or red spots appearing on the skin as a result of tiny hemorrhages.
Medical Terminology Rule #2: Words Ending in -ax.
When the singular form of the word ends with -ax, drop the -x and add -ces.
Thorax The upper part of the trunk that contains the rib cage, lungs some of the abdominal organs.
Pneumothorax Air in the pleural space which causes the lung to collapse.
Medical Terminology Rule #3: Words Ending in -ex.
When the singular form of the word ends with -ex, drop the -ex and add -ices.
Vortex A whirlpool effect caused by a spinning mass of fluid.
Apex The top of the summit.
Cortex The outer layer of an organ.
Medical Terminology Rule #4: Words ending in -is.
When the singular form of the word ends with -is, drop the -is and add -es
Metastasis When a tumor cell moves from the primary location and establishes a remote location.
Diagnosis Identification of a disease or a condition
Anastomosis The connection between two vessels
Prosthesis An artificial device used to replace a missing body part.
Medical Terminology Rule #5: Word Ending in -ix.
When the singular form of the word ends with -ix, drop the -x and add -ces.
Cervix The part of the uterus that protrudes into the vagina.
Appendix An accessory part. The vermiform appendix is a process extending from the cecum.
Medical Terminology Rule #6: Words ending in -ma.
When the singular form of the word ends with -ma, keep the -ma and add -ta.
Sarcoma A malignant neoplasm of the soft tissue.
Fibroma Benign neoplasm made of connective tissue.
Medical Terminology Rule #7: Words ending with -on.
When a singular form of the word ends with -on, drop the -on and add -a.
Ganglion A knotlike mass of nervous tissue.
Spermatozoon A mature male germ cell.
Medical Terminology Rule #8: Words ending with -us.
When a singular form of the word ends with -us, drop the -us and add -i
Thrombus An aggregation of platelets, fibrin and clotting factors. Is also known as a blood clot,
Bronchus A air passage in the lung.
Alveolus Tiny air sacs of the lung formed in clusters.
Embolus A piece of a thrombus that travels in the bloodstream until it becomes lodged in a vessel.
Calculus An abnormal stone formed in the body usually found in the urinary tract.
Bacillus A rod-shaped bacteria.
Medical Terminology Rule #9: Word ending with -um.
When a singular form of the word ends with -um, drop the -um and add -a
Bacterium A unicellular micro-organism.
Diverticulum A pouchlike herniation through the muscular wall of an organ like the small intestine.
Atrium A chamber or cavity such as on the right and left side of the heart.
Ovum An egg.
Medical Terminology Rule #10: Words ending with -y.
When a singular form of the word ends with -y, drop the -y and add -ies.
Therapy The treatment of a disease or condition.
Biopsy The removal of a small piece of living tissue for a microscopic examination to confirm or establish a diagnosis.
Medical Terminology Rules #11: Words ending with -x.
When a singular form of the word ends with -x, drop the -x and add -ges.
Larynx The organ of voice.
Meninx The three membranes that enclose the brain and spinal cord.
Phanlnx Bones of the fingers and toes.
Hopefully, this article will give you some additional basic concepts of medical terms to assist you in building a medical vocabulary. As you acquire more basic skills you will increase your understanding of medical terminology.
For additional information on Medical Terminology read the article Medical Terminology Basics!
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