1.4 Combining Forms


Combining forms are the combination of the root and the combining vowel. The root gives the essential meaning of the medical term. The combining vowel is usually an o but occasionally an i.

The following tables go through some of the most common combining forms, their meaning, and an example of a medical term that uses the combining form. Illustrations, key concept textboxes, and review questions are included to help you better understand the combining forms. It is very important that you become familiar with all of them. Making flashcards and reviewing them daily is very important when learning a new language.

 

Table 1.1. Combining Forms   

COMBINING FORM MEANING EXAMPLE OF USE IN MEDICAL TERMS
abdomin/o abdomen
aden/o gland
amni/o amnion sac
an/o anus
append/o appendix
angi/o vessel
arteri/o artery
ather/o plaque
arthr/o joint
axill/o armpit
bi/o life
bronch/o bronchial tube
bronchi/o bronchial tube
carcin/o cancer
cardi/o heart
carp/o wrist
cephal/o head
cerebr/o cerebrum

 

normal knee and knee with osteoarthritis
Fig. 1.1

Key Concept

Fig. 1.1 is an image of a normal knee and a knee that has osteoarthritis. If you break this term apart, it means “inflammation” (-itis) of the “bone” (oste/o) and “joint” (arthr/o). Note that the combining vowel is dropped because the suffix starts with a vowel.

 

picture of the lobes of the cerebrum
Fig. 1.2

Key Concept

Fig. 1.2 identifies the lobes of the cerebrum. If you break down this term, it means a “structure” (-um) surrounding the “cerebrum” (cerebr/o). Note that you drop the combining vowel because the suffix begins with a vowel.

 

Exercises

 

Table 1.2. Combining Forms

COMBINING FORM MEANING EXAMPLE OF USE IN MEDICAL TERMS
chem/o drug
cholecyst/o gallbladder
chron/o time
col/o colon
cost/o ribs
crani/o skull
cry/o cold
cutane/o skin
cyst/o urinary bladder, sac with fluid
cyt/o cell
derm/o skin
dermat/o skin
dur/o dura mater
electr/o electricity
encephal/o brain
enter/o intestine (usually small)
erythr/o red
esophag/o esophagus

 

Fig. 1.3
different types of blood cells.
Fig. 1.4

 

 

 

 

 

 

 

 

 

 

Key Concept

An electroencephalogram (EEG) is a common diagnostic test that looks at the electrical activity of the brain. This term means “to record” (-gram) “electricity” (electr/o) in the “brain” (encephal/o). Fig. 1.3 shows a patient getting an electroencephalogram.

Fig. 1.4 is an image of several different types of blood cells. The larger disc-shaped ones are erythrocytes (red blood cells), the round, fuzzy cells are leukocytes (white blood cells), and the tiny disc-shaped cells are thrombocytes (platelets). The term erythrocyte comes from the suffix -cyte, meaning “cell,” and the combining form erythr/o, meaning “red.” Literally, it means “cell that is red” or, more commonly, “red blood cell.”

 

Exercises

 

Table 1.3. Combining Forms

COMBINING FORM MEANING EXAMPLE OF USE IN MEDICAL TERMS
gastr/o stomach
glyc/o sugar
gnos/o knowledge
gynec/o women, female
hem/o blood
hemat/o blood
hepat/o liver
hyster/o uterus
inguin/o groin
isch/o to hold back
lapar/o abdomen
laryng/o voice box
later/o side
leuk/o white

 

laparotomy
Fig. 1.5

Key Concept

A laparotomy scar is shown above in Fig. 1.5. This term means “to cut” (-tomy) into the “abdomen” (lapar/o).

 

Exercises

Table 1.4. Combining Forms

COMBINING FORM MEANING EXAMPLE OF USE IN MEDICAL TERMS
mamm/o breast
mast/o breast
men/o menses
mening/o meninges
my/o muscle
myel/o spinal cord, bone marrow
nat/i birth
necr/o death
nephr/o kidney
neur/o nerve
onc/o tumour
oophor/o ovary
ophthalm/o eye
oste/o bone
ot/o ear

 

opthalmoscope
Fig. 1.6

Key Concept

Fig. 1.6 is an image of an ophthalmoscope, an instrument used to view and assess the eye. The term means an “instrument” (­scope) to view the “eye” (ophthalm/o). In this term, you keep the combining vowel because the suffix starts with a consonant.

Also, notice the combining form nat/i, meaning “birth,” in the table above. It is one of the few combining forms where the vowel is an i, not an o.

Exercises

 

Table 1.5. Combining Forms

COMBINING FORM MEANING EXAMPLE OF USE IN MEDICAL TERMS
path/o disease
pelv/o pelvis
peritone/o peritoneum
phleb/o vein
plas/o formation, growth, development
pneumon/o lung
psych/o mind
pulmon/o lung
radi/o X-ray
ren/o kidney
rhin/o nose
salping/o fallopian tube
sarc/o flesh
scapul/o shoulder blade
septic/o infection
son/o sound
thorac/o chest

 

Key Concept

Septicemia means “blood infection,” or literally “blood condition,” from the suffix -emia, and the combining form septic/o, which means “infection.” Septicemia is one of the most serious infections you might see in patients. Depending on when it is identified and the type of infection, the mortality rate can be up to 50% (John Hopkins Medicine, 2022a).

 

ultrasound
Fig. 1.7

Key Concept

Fig. 1.7 is an image of a fetus created using ultrasonography. An ultrasound can be completed on many locations of the body for diagnostic purposes. The term ultrasonography means “process of recording” (-graphy) “beyond” (ultra-) “sound” (son/o).

 

Exercises

 

 

Table 1.6. Combining Forms

COMBINING FORM MEANING EXAMPLE OF USE IN MEDICAL TERMS
thyroid/o thyroid gland
tonsill/o tonsil
top/o to put, to place, to position
thromb/o clotting
trache/o windpipe (trachea)
ur/o urine or urea, urinary tract
urethr/o urethra
uter/o uterus
vascul/o blood vessel
ven/o vein

 

Key Concept

The combining form ur/o means “urine” or “urea.” In the term uremia, ur/o means “urea.” This term means “blood condition” (-emia) with “urea” (ur-). Urea is a waste product in blood that builds up when the kidneys are not functioning properly (Betts et al., 2013).

The term uremia often gets confused with the term hematuria; however, hematuria means “a condition of urine” (-uria) with “blood” (hemat-) (Ansorge, 2022).

 

tonsillitis
Fig. 1.8
tracheostomy
Fig. 1.9

 

 

 

 

 

 

 

 

 

Key Concepts

Fig. 1.8 is an image of inflamed tonsils, or tonsillitis. This term means “inflammation” (-itis) of the “tonsils” (tonsill/o).

Fig. 1.9 is an image of a tracheostomy. This term means an “opening” (-stomy) into the “trachea” (trache/o). There are a number of medical conditions that require a patient to have a tracheostomy, including major burns, long-term comas, and certain types of tumours (John Hopkins Medicine, 2022b).

 

Exercises

 

Attribution

Unless otherwise indicated, material on this page has been adapted from the following resource:

Carter, K., & Rutherford, M. (2020). Building a medical terminology foundation. eCampusOntario. https://ecampusontario.pressbooks.pub/medicalterminology/ licensed under CC BY 4.0

 

References

Ansorge, R. (2022). Blood in urine (hematuria). WebMD. https://www.webmd.com/digestive-disorders/blood-in-urine-causes

Betts, J. G., Young, K. A., Wise, J. A., Johnson, E., Poe, B., Kruse, D. H., Korol, O., Johnson, J. E., Womble, M., & DeSaix, P. (2013). Anatomy and physiology. OpenStax. https://openstax.org/details/books/anatomy-and-physiology licensed under CC BY 4.0.

John Hopkins Medicine. (2022a). Septicemia. https://www.hopkinsmedicine.org/health/conditions-and-diseases/septicemia#:~:text=Septicemia%2C%20or%20sepsis%2C%20is%20the,the%20type%20of%20organism%20involved

John Hopkins Medicine. (2022b). Tracheostomy service. https://www.hopkinsmedicine.org/tracheostomy/about/reasons.html#:~:text=A%20tracheostomy%20is%20usually%20done,deliver%20oxygen%20to%20the%20lungs

 

Image Credits
(Images are listed in order of appearance)

Osteoarthritis by BruceBlaus, CC BY-SA 4.0

Cerebrum lobes by CSSKG, CC BY-SA 4.0

EEG cap by Thuglas, Public domain

SEM_blood_cells by Bruce Wetzel, Public domain

Exploratory Laparotomy Scar by jessica raphaela, CC BY-SA 2.0

Ophthalmoscope by Joyce Tiu, CC BY-SA 4.0

2003-10-22 Echo Tweeling-01 by DESIDERIUS, Public domain

Tonsillitis by Michaelbladon, Public domain

Tracheostomy NIH by National Heart, Lung, and Blood Institute (NHLBI), Public domain

 

 

License

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The Language of Medical Terminology by Lisa Sturdy and Susanne Erickson is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

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