Unit One - Medical Terminology Foundations

prefix

Word part at the beginning of a medical term that changes the
meaning of the word root.

suffix

word part at the end of the term that changes meaning

Combining form vowel

used to join word parts to ease pronunciation

word root

foundational meaning of a word

Language Rules for Building Medical Terms

1. When combining two combining forms, you keep the combining form vowel.
2. When combining a combining form with a suffix that begins with a consonant, you keep
the combining form vowel.
3. When combining a combining form with a suffix that begins with a vowel, you drop the
combining form vowel.
4. A prefix goes at the beginning of the word and no combining form vowel is used
5. When defining a medical word, start with the suffix first and then work left to right
stating the word parts. You may need to add filler words. As long as the filler word does
not change the meaning of the word you may use it for the purpose of building a
medical vocabulary. Once you start to apply the word in the context of a sentence it will
be easier to decide which filler word(s) to choose.

a-, an-

without; lacking

anemia

ante-

before; forward

antenatal

anti-

against

antibiotic

bi-

two

biceps

brady-

slow

bradycardia

dia-

across; through

diagnosis

dys-

difficult, abnormal bad: painful

dyspnea

endo-

within; inner

endocrine gland

epi-

above; beyond; excessive

epidermis

erythro-

red

erythrocyte

hyper-

above; beyond; excessive

hyperactive

hypo-

under; deficient

hypothyroidism

inter

between

interstitial fluid

intra-

within

intracellular fluid

mal-

bad; abnormal

malignant

melano-

black

melanin

neo-

new

neonate

oligo-

few; little

oliguria

pan-

all; entire

pancytopenia

peri-

around

pericardium

poly-

many; excessive

polyuria

sub-

under

subcutaneous layer

syn-

together

syndrome

tachy-

fast

tachycardia

trans-

across; through

transdermal

-ac

pertaining to

cardiac

-al

pertaining to

spinal

-centesis

surgical puncture to remove fluid

thoracentesis

-desis

surgical binding

arthodesis

-ectomy

cut out; surgical removal

mastectomy

-emia

blood condition

anemia

-ia

condition

hemophilia

-ism

condition

hypothyroidism

-itis

inflammation

arthritis

-lysis

break down; destruction; dissolving

hemolysis

-malacia

softening

osteomalacia

-megaly

enlargement

acromegaly

-oid

resembling

rheumatoid

-oma

tumor; mass; fluid collection

angiosarcoma

-osis

condition; abnormal

endometriosis

-pathy

disease

lymphadenopathy

-penia

deficiency; lack of

thrombocytopenia

-pexy

surgical fixation

oophoropexy

-plasia

growth

hyperplasia

-plasty

surgical reconstruction

vertebroplasty

-plegia

paralysis

hemiplegia

-pnea

breathing

sleep apnea

-rrhage

burst forth; excessive bleeding

hemorrhage

-rrhea

flow or discharge

diarrhea

-stomy

surgical creation of an opening

colostomy

-tomy

incision; to surgically cut into

laparotomy

-trophy

growth

hypertrophy

molecule

the chemical building blocks of all body structures

cell

the smallest independently functioning unit of a living organism

tissue

a group of many similar cells (though sometimes composed of a few related types) that work together to perform a specific function

organ

an anatomically distinct body structure of two or more tissue types. Each organ performs one or more specific physiological functions.

prone

lying face down

supine

lying face up

cranial cavity

houses the brain. Protected by the bones of the skulls and cerebrospinal fluid.

-al: pertaining to

crani/o: skull

spinal cavity

encloses the spinal cord.

-al: pertaining to

spin/o: spine (backbone)

thoracic cavity

The more superior subdivision of the anterior cavity, and it is enclosed by the rib cage.
The thoracic cavity contains the lungs and the heart, which are located in the mediastinum.
The diaphragm forms the floor of the thoracic cavity and separates it from the more inferior abdominopelvic cavity.

-ic: pertaining to

thorac/o: chest

abdominopelvic cavity

The abdominopelvic cavity is the largest cavity in the body. The abdominal cavity houses
the digestive organs, the pelvic cavity, and the reproductive organs.

-ic: pertaining to

abdomin/o: abdomen

pelv/o: pelvis; hip region

anterior (ventral)

Describes the front or direction toward the front of the body. The toes are anterior to the foot.

-al: pertaining to

later/o: side

posterior

Describes the back or direction toward the back of the body. The popliteus (back of the knee) is posterior to the patella.

-ior: pertaining to

poster/o: back (of body); behind

superior

Describes a position above or higher than another part of the body proper. The orbits are
superior to the oris.

-ior: pertaining to
superfic/o: of or belonging to the surface

inferior

Describes a position below or lower than another part of the body proper; near or toward
the tail (in humans, the coccyx, or lowest part of the spinal column). The pelvis is inferior to the abdomen.

-ior
pertaining to
infer/o
lower in situation or place

lateral

Describes the side or direction toward the side of the body. The thumb (pollex) is lateral to
the digits.

-al: pertaining to
later/o: side

medial

Describes the middle or direction toward the middle of the body. The hallux (big toe) is
the medial toe.

-al: pertaining to
medi/o: middle

proximal

Describes a position in a limb that is nearer to the point of attachment or the trunk of the body. The brachium is proximal to the antebrachium.

-al: pertaining to

proxim/o: near

distal

Describes a position in a limb that is farther from the point of attachment or the trunk of the
body. The knee is distal to the femur.

-al: pertaining to
dist/o: far; distant

superficial

Describes a position closer to the surface of the body. The skin is superficial to the bones.

-al: pertaining to
superfic/o: of or belonging to the surface

deep

Describes a position farther from the surface of the body. The brain is deep to the skull.