Anatomical Terminology

Body Positions

In the anatomical position, the body is erect, with the face directed forward, and the arms are at the side with the palms of the hands facing forward. The anatomical position serves as a reference point when using directional and regional terms.

When describing human anatomy, it is important to have a fixed reference point to eliminate confusion. Words such as left and right can be subjective, because it is unclear as to whether the person's left or the doctor's left is being described. The anatomical position eliminates this confusion by serving as the standardized position to which all things are referred. The anatomical position uses the person's perspective and not the doctor's so that the right hand is on the right side of the body and the left hand is on the left. In this position, the body is standing up straight with the face forward. The arms are at each side with the palms of the hands also facing forward. Directional terms such as anterior and posterior, medial and lateral, abduction and adduction, and so on apply to the body when it is in the anatomical position. The following descriptive terms may be used when speaking of body positions:

  • Prone: when the body is positioned lying face down
  • Supine: when the body is positioned lying face up
  • Unilateral: referring to one side of the body
  • Bilateral: referring to both sides of the body

Illustration of the Human Body in the Anatomical Position

The anatomical position is the standard point of reference in human anatomy. It allows for the precise description of structural locations within the body.
Many of the words used in the biological and health sciences include a common set of prefixes, suffixes, and root words often derived from Greek and Latin. These compound words allow for a more precise description of the human form that helps to eliminate ambiguity. Prefixes are placed before the root word and can add a variety of meanings to that word, including characteristics such as time, position, amount, and color. Similarly, suffixes placed at the end of the root can clarify specific symptoms, processes, or conditions. Altering any of these components allows for quite varied expression in anatomical terminology. For example, the term periphlebitis, which refers to an inflammation around the veins, uses the prefix peri-, meaning "around," and the suffix -itis, meaning "inflammation." The root word phleb is derived from the Greek phlebo, meaning "vein." In this way, seemingly complex terms can be understood by simply breaking them down into their component parts.

Common Prefixes

Category Prefix Definition Example
Time brady- slow bradypnea: slow breathing
inter- between intermenstrual: between periods
intra- during /within intraoperative: during the operation
neo- new neoplasm: new growth (tumor)
peri- around perinatal: around the time of birth
post- after postictal: after the seizure
pre- before precancerous: before (becoming) cancer
presby- old age presbyopia: age-related visual problem
tachy- fast tachycardia: fast heartbeat
Position circum- around circumvascular: surrounding the blood vessels
ecto- on the outside ectopic pregnancy: pregnancy outside the uterus
endo- on the inside endoskeleton: the inner skeleton
extra- outside of extra-articular: outside the joint
inter- between intercellular: between cells
intra- inside intranuclear: inside the nucleus
peri- around perirenal: around the kidney
post- behind postnasal: behind the nasal cavity
pre- in front of prepatellar: in front of the kneecap
sub- under subcutaneous: under the skin
supra- over supradiaphragmatic: above the diaphragm
trans- through transurethral: through the urethra
Amount bi- two bipedal: two feet
centi- one-hundredth centimeter: one-hundredth of a meter
hemi- half hemiretina: half the retina
hyper- excessive hyperthyroid: excessive thyroid function
hypo- deficient hypoglycemia: deficient sugar in the blood
kilo- one thousand kilogram: one thousand grams
macro- large macrocytic: large cell
mega- large, million megacolon: enlarged colon; megameter: a million meters
micro- small microcirculation: very small blood vessels
milli- one-thousandth millisecond: one-thousandth of a second
mono- one monocular: one eye
multi- many multicellular: many cells
nano- one-billionth nanometer: one-billionth of a meter
oligo- too little or too few oliguria: too little urine production
poly- too much polydipsia: too much thirst/drinking
tri- three tricuspid: three-cusp valve
uni- one unilateral: one side
Color cyano- blue cyanosis: blue coloration to the skin
erythro- red erythrocyte: red blood cell
leuko- white leukemia: cancer of the white blood cells
melano- dark melanoma: dark-colored cancerous lesion
xantho- yellow xanthoderma: yellow coloration of the skin
Other anti- against antibiotic: agent against/destroys bacteria
dys- abnormal dysfunction: abnormal function/behavior
eu- normal euthyroid: normal thyroid function
mal- bad malabsorption: poor absorption
pseudo- false pseudomembrane: false/not real membrane

Common prefixes used in anatomical terminology.

Common Suffixes

Suffix Definition Example
Symptoms -algia pain neuralgia: pain along the nerve
-dynia pain arthrodynia: pain in the joints
-emesis vomiting hematemesis: vomiting blood
-phoria feeling dysphoria: feeling unpleasant
-plegia paralysis quadriplegia: paralysis of all four limbs
-pnea breathing dyspnea: trouble/abnormal breathing
-rrhea flow/discharge rhinorrhea: runny nose
-thermia temperature hypothermia: low temperature
-uria urine hematuria: blood in the urine
Processes -centesis surgical puncture to withdraw fluid arthrocentesis: withdrawal of fluid from a joint
-ectomy removal of pneumonectomy: removal of a lung
-gen a cause pathogen: cause of infection
-genesis development carcinogenesis: development of cancerous lesion
-gram test/exam result echocardiogram: result of a test of the function of the heart
-graphy test/exam mammography: test to examine the breasts
-metry measurement audiometry: the measurement of one's hearing
-opsy viewing necropsy: viewing/studying the body after death
-pepsia digestion dyspepsia: indigestion
-phagia eating/swallowing dysphagia: difficulty swallowing
-phasia speech dysphasia: difficulty with speaking
-scopy use of an instrument for viewing microscopy: use of a microscope for viewing
-stomy mouth/opening tracheostomy: opening in the trachea
-therapy treatment chemotherapy: treatment with drugs
-tomy creating an opening/cut tracheotomy: creation of a tracheostomy
Conditions -emia blood condition polycythemia: too many cells in the blood
-itis inflammation iritis: inflammation of the iris/front part of the eye
-megaly enlargement hepatomegaly: enlarged liver
-oma tumor thymoma: tumor of the thymus gland
-opia vision hyperopia: ability to see far away
-osis disease nephrosis: disease of the kidney
-pathy disorder cardiopathy: disorder of the heart
-sclerosis hardening atherosclerosis: hardening of the arteries
Other -ac pertaining to cardiac: pertaining to the heart
-al pertaining to nasal: pertaining to the nose/nasal cavity
-ar pertaining to tonsillar: pertaining to the tonsils
-cide killing fungicide: a medicine that kills fungi
-cyte cell leukocyte: white blood cell
-iatry medical treatment physiatry: treatment to restore physical mobility
-ic pertaining to gastric: pertaining to the stomach
-logy study of histology: the study of microanatomy
-prandial relating to a meal postprandial: after eating

Common suffixes used in anatomical terminology.