Medical Etymology

The following terms are taken from Medical Etymology. The History and Derivations of Medical Terms for Studens of Medicine, Dentistry, and Nursing. By: O.H. Perry Pepper, M.D. Professor of Medicine, University of Pennsylvania.


The following abbreviations are used to describe the origin of the word.

Ar. = Arabic
AS. = Anglo Saxon
Ch. = Chinese
Eng. = English
Ger. = German
Gr. = Greek
Ital. = Italian
L. = Latin
ME. = Middle English
ML. = Medieval Latin
Mod.L. = Modern Latin
OE.= Old English
OF. = Old French
Sp. = Spanish

abdomen The orgin of this term is not known. Perhaps it is derived from the Latin abdere = to hide; hence it might mean the cavity in which odds and ends are hidden away. Others believe it has come from the Latin root adeps = fat.

abducens See ABDUCTOR.

abductor L. ab = away from, and ducere = to lead. These muscles are named for their function, and the abducens nerve similarly is named because it turns the eyeball outward.

accessory L. accedere = to be added to; from ad = to, and cedere = to come. The accessory nerve is functionally accessory to the vagus.

accommodation L. accommodare = to make fit; from ad = to, and commodare = to adjust.

acetabulum L. acetum = vinegar, and -bulum, a suffix signifying the instrument. This cup-shaped part of the hip was thought to resemble a small vinegar cruet of roman times.

acetylcholine L. acetum = vinegar, and Gr. chole = bile. From acetum came acetic and acetyl; from chole came choline. It is the acetyl derivative of choline.

achilles Gr. The infant Achilles was dipped into the river Styx by his mother to render him impervious to wounds. She held him by his heel, which remained vulnerable, and it was in the heel that he was fatally wounded by an arrow at the battle of Troy.

achondroplasia Gr. a = not, chondros = cartilage, plasis = a molding, and -ia = condition. In other words, a failure of normal development of cartilage.

acinus L. acinus = grape.

acoustic Gr. akoustikos = pertaining to hearing. Hence the auditory nerve.

acromegaly Gr. akron = tip or extremity, and megas = large.

acromion Gr. akron = tip or summit, and omos = shoulder. The word akron gives the combing forms acra- or acro-.The famous Acroplois in Athens was built on a summit.

adductor L. ad = to, and ducere = to lead. The muscles so named draw the part toward the medial line.

adenocarcinoma Gr. aden = gland, and carcinoma (see below).

adenoid Gr. aden = gland, and eidos = resemblance.

adipose L. adiposus; from adeps = fat.

adrenal L. ad = to, and renal from ren = kidney. The adrenal gland lies above the kidney and is sometimes called the suprarenal.

adventitia L. adventitius = coming from abroad; from ad = to, and venire = to come.

afferent L. ad (af-) = to, and ferre = to carry. Used for a variety of structures carrying material or impulses to a center or to an organ.

ala L. ala = a wing. It is believed that ala is an eroded form of axilla.

albicans L. albicare = to be white.

alimentary L. alimentum = nourishment. An adjective applied to the digestive system or alimentary canal.

allantois Gr. allas = a sausage, and eidos = resemblance.

alveolus L. diminutive of alveus = any hollowed out structure.

ameloblast OF. en = on, amel = enamel, and Gr. blastos = germ.

ampulla L. ampulla = a jug. Perhaps an onomatopoetic word whose sound suggests the object; in this case, fluid flowing from the jug. Applied in anatomy to a number or structures supposedly resembling a jug.

amygdala Gr. amygdale = an almond. Applied to the tonsil, because of a similarity in shape.

anastomosis Gr. ana = up, and stoma = mouth; hence an opening up.

anatomy Gr. ana = up or apart, tome = a cutting.

anencephaly Gr. a(an-) = not, and enkephalon = brain. One of the many congenital defects.

aneurysm Gr. aneurysma = a widening; from ana = across, and eurys = broad.

angio- Gr. angeion = a vessel.

annulus L. anus = ring, and -ulnus, a diminutive suffix. Applied to many small, ring-shaped structures.

antero- L. anterior = in front of.

antrum Gr. antron = a cave. The antra are hollow caves in our skull.

anus L. anus = a ring. The terminal orifice of the bowel with its "ringed" musculature.

aorta Gr., perhaps from aeirein = to lift up, or to be hung. Hippocrates used it of a bronchus; Aristotle transferred use of the term to the artery from which the heart hangs. The word was taken over into Latin as aorte, and first appeared as aorta in English in 1594.

apical L. apex = tip, top, or pointed end. The genitive of apex is apicis, and this explains the adjective apical.

aponeurosis Gr. apo = from, and neuron = anything of a fibrous nature. Previous to Aristotle the word neuron had this meaning, and in Athens a cobbler was a neurorrhaphos or one who sews with tendons. This offers a good idea of the state of anatomical knowledge at that period. Aristotle limited use of the term neuron to the nerves.

appendix L. appendere = to hang upon; from ad = to, and pendere = to hang. Used since the early seventeenth century to mean a small process developed from the surface of an organ.

aqueduct L. aqua = water, and ductus = a canal. In Latin the word was spelled aquaeductus, which explains why we spell it with an e.

arachnoid Gr. arachne = spider, and eidos = resemblance. From this root came a Latin term arachnoides = spider-like, and from this came the name arachnoid for the cobweb-like membrane covering the brain and spinal cord.

areola L. area = a courtyard or space, and diminutive suffix -ola. A term used in several ways, but especially applied to the pigmented area around the nipple.

artery Gr. perhaps from aer = air, and terein = to keep. This derivation suggests the ancient belief that the arteries were windpipes. Adopted into Latin as arteria with the same meaning until the time of Harvey.

articulation L. articulus, diminutive or artus = joint, and -atio, a suffix originally denoting action.

arytenoid Gr. arytaina = a pitcher, and eidos = resemblance. The arytenoid cartilages were thought to resemble little pitchers.

ascites Gr. askos = a bag or bladder. No better name could be given to the fluid-filled abdomen. Sometimes ascites is applied to the fluid itself.

astigmatism Gr. a = not, and stigma = a point. Hence a failure of the light rays to focus.

astrocyte Gr. astron = a star, and kytos = a vessel or cell. These cells are shaped like stars.

ataxia Gr. a = not, taxis = order, and -ia = condition. Applied to a lack of muscular coordination.

atelectasis Gr. ateles = imperfect, and ektasis = expansion.

atheroma Gr. athere = porridge; an unexpected derivation, but a good descriptive term. The combing form athero-, from the same stem, appears in the compound term atherosclerosis (skleros = hard).

atlas Gr. Atlas was the mythological Titan who supported the world on his shoulders. Vesalius, in the sixteenth century, gave this name to the first cervical vertebra, which supports the head.

atresia Gr. a = not, tresis = a boring, and -ia = a condition. Hence an abnormal closure of an opening.

atrium L. atrium = a hall, or an entrance, and therefore used for the upper chamber of the heart.

atrophy Gr. a = without, and trophe = nourishment.

atropine Gr. Atropos = one of the Fates, after whom the botanical genus Atropa is named, perhaps because the drug extracted from Atropa belladonna can quickly decide your fate.

auditory L. audire = to hear.

auricle L. auricula, diminutive of auris = ear. Used in anatomy of any ear-shaped structure, but applied especially to the appendage of the upper chamber of each side of the heart, because they bear a rough resemblance to ears.

autonomic Gr. autos = self, and nomos = law. Hence that part of the nervous system which is self-controlled or autonomous.

autopsy Gr. autos = self, and opsis = to look at. In the third century B.C., the word autopsia denoted those observations on the patient made by the physician himself, in contrast to historia, supplied by the patient.

axial L. axis = axle or pivot

axilla L. axilla = the armpit.

axis L. axis = axle or pivot. Used as a name of the second cervical vertebra.

azygos Gr. a = not, and zygos = a yoke. Therefore, this applies to any unpaired or unyoked structure, such as the azygos vein or the azygos lobe of the lung.

basilar Mod. L. basilaris = basal; originally from Gr. basis = a base.

bicuspid L. bi = two, and cuspis = point. The term premolar is also used for these teeth.

bile L. bilis = bile. Many medical terms come from this root, bilis, including bilirubin (ruber = red) and biliverdin (viridis = green).

biopsy Gr. bios = life, and opsis = vision. Hence biopsy signifies an examination of tissue removed from the living body.

blastula Gr. blastos = germ or bud, and derma = skin.

brachial L. brachium = an arm.

bradycardia Gr. bradys = slow and kardia = heart.

bregma Gr. bregma = front of the head.

brevis L. brevis = short.

bronchial Adjective from BRONCHUS.

bronchus Gr. bronchos = windpipe; originally from Gr. brechein = to moisten. Plato believed that swallowed liquids went down the trachea into the bronchi.

bruit Fr. bruit = sound or noise.

buccal L. bucca = the cheek.

buccinator L. buccinator = a trumpeter. Hence the muscles of the cheek.

bulla L. bulla = a bubble. The adjective is bullous; both are used of a lesion which resembles a bubble.

bursa ML. bursa = a purse, hence any closed sac.

cadaver L. cadere = to fall dead.

calcaneus L. calcaneus = relating to the heel.

calyx Gr. kalyx = husk or cup. A term applied especially to the recesses in the pelvis of the kidney.

canthus Gr. kanthos = corner of the eye.

capillary L. capillaris = relating to the hair; hence any structure as fine as a hair.

caput L. caput = head.

caput medusae L. caput = head, and genitive of Medusa = one of the mythological Gorgons with hair of live snakes. The term is applied to the dilated veins which appear on the abdomen, due to obstruction of the portal circulation.

carcinoma Gr. karkinos = a crab, and -oma = tumor or neoplasm. Celsus used the word carcinoma for all malignant growths, but added the adjective kakoethes = malignant to designate some which required surgery.

cardia Gr. kardia = heart. Used to denote the end of the stomach lying nearest the heart.

carina L. carina = keel of a boat, hence used of several anatomical structures having a central ridge.

carotid Gr. karoun = to put to sleep. In early Greece, jokesters used to cause goats to fall down motionless by pressure on these arteries and to return to normal by release of pressure. This is because horses and goats depend entirely on the carotids for their cerebral blood supply, since the vertebral arteries are insufficient. (An ancient day "sleeper hold".)

cartilage L. cartilago = gristle.

cauda L. cauda = a tail. Such as the cauda equina or "horse's tail" of the spinal cord.

cava L. cavus = hollow, as in the word cave.

cecum L. caecus = blind.

celiac Gr. koilia = the belly.

cell L. cella = a small chamber.

cephalic Gr. kephale = head.

cerebellum L. diminutive of cerebrum = brain.

cerebrum L. cerebrum = brain.

cervical Look at cervix.

cervix L. cervix = neck. Most often used of the neck of the uterus.

chiasm Gr. chiasma = two crossing lines. Derived from the Greek letter chi which in Greek script was written c.

choana Gr. choane = a funnel. Applied to the posterior naris.

cholangitis Gr. chole = bile, angeion = vessel, and -itis = inflammation.

chondral Gr. chondros = cartilage.

chorda L. chorda = a string or cord. In Greek, the corresponding word chorde signifies the intestine.

choroid Gr. chorion = skin, and eidos = resemblance.

chyle Gr. chylos = juice.

chyme Gr. chymos = juice. Used by Plato, and taken into medical terminology a long time ago. It is now seldom employed alone, but the roots persists in such terms as parenchyma and mesenchyme.

ciliary L. ciliaris = pertaining to eyelashes; from cilia = eyelashes. Used of any hair-like structure.

circulation L. circulare = to make a circle. The movement of the blood was known to follow a circular course.

cirrhosis Gr. kirrhos = tawny yellow. Laennec coined this term for the yellowish liver of fat and fibrosis. It now has a wider application, tending to connote fibrosis irrespective of color.

cisterna L. cisterna = a reservoir or cistern.

clavicle L. clavicula, diminutive of clavis = a key. So named for its resemblance in shape.

coccyx Gr. kokkyx = cuckoo. Adopted for anatomy from a supposed resemblance of this bone to the beak of a cuckoo.

coelom Gr. koiloma = a hollow. Used in embryology, and as a name for the general body cavity in the adult.

collagen Gr. kolla = glue, and gennào = to produce.

commissure L. commissura; from con (com-) = together, and mittere = to put. Hence a joining or a seam.

condyle Gr. kondylos = a knuckle.

conjunctiva L. con = with, and jungere (junctus) = to join.

constrictor L. con = together, and stringere = to pull.

conus Gr. konos = a cone or peg. Used of various more or less peg-shaped anatomical structures: for example, the conus medullaris of the spinal cord..

cornea L. corneus = horny. The cornea of the eye was formally called the cornea tela, which meant the horny tissue or layer.

cornu L. cornu = a horn. Applied especially to horn-shaped structures in the CNS.

coronary L.coronarius = pertaining to or like a crown. Applied especially to the arteries of the heart, so called because they encircle the organ as a wreath or crown.

corpus L. corpus = body.

corpus luteum L. luteus = yellow. Describing the scarring of the ovary.

cortex L. cortex = outer layer or bark. In anatomy, it is applied to the outer layer of organs.

cranium Gr. kranion = skull.

cremaster Gr. kremastos = hanging. Galen used this appropriate name for the muscle on which the testicle is hung.

cribriform L cribrum = a sieve, and forma = form. Applied to the sieve-like plate of the ethmoid bone.

cricoid Gr. krikos = a circle or ring, and eidos = resemblance.

crus L. crista = leg. Any structure in anatomy resembling a leg or, in the plural crura, of a pair of dividing structures.

cuboid Gr. kybos = a cube, and eidos = resemblance. A square bone in the foot.

cuneiform L. cuneus = a wedge, and forma = form. In anatomy for wedge-shaped bones in the wrist and ankle.

cutaneous L. cutaneus = relating to the skin; from cutis = skin.

cyst Gr. kystis = bladder.

cyto- Gr. kytos = vessel or urn; the same as the Latin vas.

dactyl Gr. daktylos = finger or toe.

decidua L. decidus = falling off. The decidua is the altered mucous membrane lining the uterus during pregnancy and puerperium.

deferens L. de = away, and ferre = to carry.

deltoid Gr. delta = the Greek letter D, and eidos = resemblance. Applied to the deltoid muscle because of its triangular shape.

depressor L. de = down, premere = to press, and the suffix -or = the agent.

diaphragm Gr. diaphragma = a wall or partition; from dia = across, and phragma = a wall.

diastole Gr. dia = apart, and stellein = to send. Hence to dilate or spread.

diencephalon Gr. dia (di-) = through, and encephalon = brain. Hence the "between" brain.

digastric Gr. di = two, and gaster = belly. A term descriptive of this muscle, which has two different bellies.

distal L. distare = to stand apart or to be distant.

dorsal L. dorsum = the back.

duodenum L. duodeni = twelve. Thus named because of its length in fingerbreadths.

dura L. durus = hard.

endocrine Gr. endon = within, and krinein = to separate. Denotes a gland whose product passes into the blood, being separated within the gland.

ependyma Gr. epi = upon, and endyma = a garment. In anatomy, applied to the lining of the spinal canal or outer covering of the spinal cord.

epicardium Gr. epi = upon, and kardia = heart.

epigastrium Gr. epi = upon, and gaster = stomach.

epiphysis Gr. epi = upon, and physis = growth.

epiploic Gr. epiploon = omentum. The epilploic appendages hang from the omentum.

epispadas Gr. epi = upon, and spadon = a rent or tear. Applies to a congenital opening of the urethra on the upper surface or dorsum of the penis.

erector L. erectus = upright. Applied to a muscle which causes a structure to stand upright.

esophagus Gr. oisophagos = gullet. The Greek term was formed from oiso, the future tense of phero = to carry, and phagein = food.

ethmoid Gr. ethmos = a sieve, and eidos = resemblance. A term describing the structure of the ethmoid bone of the skull.

eversion L. evertere = to turn outward; from ex (e-) = out, and vertere = to turn.

extensor L. extendere = to stretch out.

extrinsic L. extrinsecus = originating or acting outside; from exter = outside, and -secus = on the side.

falciform L. falx = sickle, and forma = form. The falciform ligament has this shape.

fascia L. fascia = a ribbon or fillet.

femur L. femur = thigh, but applied to the bone of the upper leg. The adjective femoral is used of various structures in the thigh.

fibula L. fibula = a clasp or a pin; originally from figo = fasten.

fimbria L. fimbria = fringe. Applied to the processes at the abdominal end of the fallopian tube.

flexor L. flectere = to bend. From the same root comes the word flex, flexion, and flexure = a fold or crease

follicle L. folliculus, diminutive of follis = a bag.

foramen L. foramen = an opening; from forare = to bore.

fornix L. fornix = arch or vault.

fossa L. fossa = a ditch. Used in anatomy for depressed areas.

fovea L. fovea = a pit. In ophthalmology it applies to the central depression in the retina.

frontal L. frons = forehead.

fundus L. fundus = bottom.

ganglion Gr. ganglion = a swelling.

gastric Gr. gaster = stomach or belly.

genitalia L. genitalis = pertaining to reproduction.

genu L. genu = the knee, but used in anatomy of any bent structure.

glabella L. glabellus = smooth. Name for the prominence on the frontal bone just above the nose.

glans L. glans = acorn. Used for the head of the penis, which is shaped somewhat like an acorn.

glenoid Gr. glene = joint socket, and eidos = resemblance. Homer used the word genoid to signify the pupil of the eye; and because of the small images seen reflected there, it also meant doll or little girl.

gluteal Gr. gloutos = buttocks.

gonad Gr. gone = a seed or generation.

gubernaculum L. gubernaculum = helm or little governor; from gubernare = to control, and the diminutive suffix -culum. The gubernaculum of the testis is the fetal cord which guides the descent of the testis.

gut AS. guttas = the bowels.

gyrus Gr. gyros = a circle.

hallux L. hallux = great toe.

hamulus L. hamulus, a diminutive of hamus = a hook. Applied to hook-shaped structures.

helicotrema Gr. helix = a coil, and trema = a hole. Applied to the communication between the two channels of the cochlear convolutions.

helix Gr. helix = a coil or screw. The coiled or turned-over margin of the auricle.

hernia L. hernia = a rupture.

hilum (hilus) L. hilum = a small thing.

humerus L. (h)umerus = the shoulder bone; related to Gr. omos = the shoulder

hydrocele Gr. hydor = water, and kele = swelling. Usually used of a collection of fluid in the tunica vaginalis of the testes.

hyper Gr. hyper = excessive.

hypo Gr. hypo = less.

ilium L. ilium = the flank, and the iliac bone. Originally because the small intestines are largely supported by this bone, and the old term for the small intestines was ilia (plural of ilium).

incisor L. incidere = to cut into; from in = in, and caedere = to cut. Applied to the eight cutting teeth.

incus L. incus (incudis) = anvil.

inguinal L. inguen = groin.

innominate L. innominatus = unnamed; from in = not, and nomen = name. There are two structures called innominate, one artery and one bone.

insertion L. in = in, and serere = to put. Hence, the point of attachment of a muscle in the more movable of the two structures which it joins.

inter L. inter = between

intestine L. intestinum = intestine. The noun intestinum came from the adjective intestinus, which meant nothing more than inner or inward. The popular term "innards" expresses the same thing.

inversion L. invertere = to turn about or inside out.

in vitro See vitreous.

in vivo See vitreous

ipsilateral L. ipse = self or same, and latus = side.

iris Gr. iris = rainbow.

ischium Gr. ischion = hip.

jejunum L. jejunus = fasting or empty. Galen named the second part of the small intestine nestis = fasting, because he believed it was always found empty after death.

joint L. jungere = to join.

jugular L. jugulum = throat. Hence these veins of the throat.

kyphosis Gr. kyphos = bent, and -osis = condition, hence humpback.

labia L. labium = lip.

labyrinth Gr. labyrinthos = a maze.

lacrimal L. lacrimal = a tear.

lateral L. latus = side.

lemniscus Gr. lemniskos = a band.

lenticular L. lens = a lentil, and a diminutive suffix. This adjective means shaped like a lentil.

levator L. levator = anything that raises; from levare = to lift.

ligament L. ligamentum = ligament; from ligare = to bind.

linea L. lien = spleen. Related to the Greek term splen = spleen.

lingula L. lingula, diminutive of lingua = tongua.

lip AS. lippa = lip

longissmus L. superlative of longus = long. Applied to the long muscles of the back.

longus L. longus = long

lordosis Gr. lordos = bent backward. Applied to the spine.

lumbar L. lumbus = the loin.

malleolus L. diminutive of malleus = hammer.

mandible L. mandibula = jaw; from mandere = to chew, and the suffix -bulum, indicating the instrument.

masseter Gr. maseter = chewer. One of the few muscles named in the writings of Galen.

mastication L. masticare = to chew.

mastoid Gr. mastos = breast or nipple, and eidos = resemblance.

maxilla L. maxilla = jaw bone.

meatus L. meatus = a channel or way.

mediastinum ML. mediastinum = medial, intermediate.

medulla L. medulla = marrow. Used for the non-cortical part of some organs, such as the kidney and adrenal.

meninges Gr. meninx = membrane; plural, meninges.

mesentery Gr. mesos = middle, and enteron = intestine.

mesoderm Gr. mesos = middle, and derma = the skin.

metacarpus Gr. meta = after or beyond, and karpos = wrist.

metatarsus Gr. meta = after or beyond, and tarsos = instep.

molar L. mola = a millstone. Hence, a grinding tooth.

muscle L. musculus, diminutive of mus = a mouse. Thus a muscle was a little mouse running about under the skin.

mylohyoid Gr. myle = a mill, and hyoid. The word myle was given to the posterior teeth, the grinders, and became mola in Latin. Hence the designation molar for these teeth. Mylohyoid, therefore, refers to the posterior part of the jaw and the hyoid bone.

nares L. naris = nostril.

navicular L. navis = boat, and the diminutive suffix -cula. Hence, this bone suggests the shape of a little boat.

node L. nodus = a knot. Used, for example, in lymph node.

nucha ML. nucha = the back of the neck. This word, originally Arabic, was adopted into Latin and changed in French to nuque.

oculomotor L. oculus = eye, and motor = producing movement. applied to the nerve supplying several muscles which move the eye.

olecranon Gr. olenokranon, from olene = elbow, and kranos = helmet. In other words, the protector of the elbow.

olfactory L. olfacere = to smell.

omphalocele Gr. omphalos = umbilicus, and kele = swelling, used here in the sense of hernia. Hence an umbilical hernia.

ophthalmia Gr, ophthalmos = eye, and -ia = disease. This suffix used to be more common but is being superseded by -itis.

opponens L. ob (op-) = against, and ponere = to place. In other words, an opposing muscle.

oral L. os = mouth; genitive, oris.

orbicular L. orbicularis = circular or disc-shaped; from orbis = circle or orb. The orbicularis muscle closes the eye.

orbit L. orbis = a ring or circle.

orchid Gr. orchis = testicle. Hence the word orchitis, for inflammation of the gonads.

orifice L. orificium = an opening.

origin L. origo = starting point.

ostium L. ostium = door or opening.

-otomy Gr. tome = a cutting.

palate L. palatum = palate.

palmar L. palma = the palm of the hand.

pampiniform L. pampinus = tendrils, and forma = form. The pampniform plexus of veins in the spermatic cord suggests a number of interwoven tendrils.

panniculus L. diminutive of pannus = cloth or covering. Hence a little covering.

papilla L. papilla = nipple.

parasympathetic Gr. para = beside, and SYMPATHETIC. A term coined as a name for the autonomic nervous system.

parenchyma Gr. para = beside, and enchyma = infusion or juice. Attributed to Erasistratus, about 300 B.C. who coined it to signify "what is poured in".

parietal L. paries = a wall.

parotid Gr. para = beside, and ous (ot) = ear. The parotid gland lies just in front of the ear.

patella L. patella = little plate.

pectinate L. pecten = a comb. Adjective form of pecten, applied to anatomical structures with projections like the teeth of a comb.

pedicle L. pes (pedis) = foot, and the diminutive suffix -culus. Hence a little foot; but the word also meant a stalk of fruit. From this latter comes the anatomical use, for the pedicle of an organ suggests the stalk of an apple or other fruit.

pelvis L. pelvis = basin. The pelvis is a basin-like structure.

penis L. penis = the male sexual organ. Originally, the word meant a tail.

peri- Gr. peri = around.

perineum Gr. perinaion = the perineum; probably from peri = around, and naiein = to dwell. The Greek perina = scrotum was probably from the same root.

peroneal Gr. perone = a brooch or pin. Adjective form of peroneus, describing the shape of the peroneus muscles.

pes L. pes = foot. The plural is pedes.

petrosal L. petrosus = stony. Adjective form of petrous. The petrous portion of the temporal bone is harder than the rest.

phalanx Gr. phalanx (plural phalanges) = soldiers in close order. A good term for the bones of the toes and fingers.

phallus Gr. phallos = penis.

pharynx Gr. pharynx = throat. The adjective pharyngeal and the name of the pharyngeus muscle come from the same source.

phrenic Gr. phren = (1) diaphragm, and (2) brain. From this word, which dates back to the time when the heart was thought to be the seat of emotions, two series of terms have been derived. From its first meaning, heart or diaphragm, we get the name of the phrenic nerve. On the other hand, from its second meaning for brain, we get phrenology and several compound terms ending in phrenia, such as schizophrenia, now transformed into frenzy. The heart continues to be thought of as the seat of the emotions only in amorous affairs, in which the mind plays a little part.

pia L. pius = kindly or tender. Pia is the feminine of pius, which is used in this gender to agree with mater = mother. Here pia mater means the tender protector of the brain and spinal cord.

pineal L. pinea = a pine cone. Presumably so named from the shape of this body.

pinna L. pinna = a wing. Applied to the external ear.

piriform L. pirum = a pear, and forma = form.

pisiform L. pisum = a pea, and forma = form.

pituitary L. pituita = mucous secretion. In the time of Galen the mucus from the nose and mouth was thought to come from the brain, hence this structure was so named. It has been suggested that the word spit comes from the same orgin. It was a long time before it was demonstrated that nasal mucus came from glands in the nose, and not through the cribriform plate of the ethmoid bone.

plantar L. planta = sole of the foot. We used this adjective form but not the noun. Curiously enough, this word planta also meant a sprout, twig, or, as might be expected, a plant.

platysma Gr. platysma = a plate.

pleura Gr. pleura = the side of the body or the ribs. But the word has come to mean the sac surrounding the lung.

pneumo Gr. pneumon = lung.

pons L. pons = a bridge.

portal L. porta = gate. The portal vein is the vein which enters the gate of the liver.

postero- L. posterus = behind

prepuce L. prae (pre-) = before, and an obsolete term, perhaps putum, for penis. Hence prepus is the male foreskin.

pronate L. pronare = to turn palm or face downward. Compare supinator.

prostate Gr. pro = before, the root sta = stand, and the suffix -tes. In ancient Greece the word prostates meant a guard or protector - one who stood before. The prostate gland does stand in front of the bladder.

proximal L. proximus = next to.

psoas Gr. psoa = a muscle in the loins.

pubis L. pubis = the pubic bone.

pupil L. pupilla, diminutive of pupa = a doll or little girl. This word pupa is used today of an early stage in the life of an insect, and also from it come our words pup, puppet, and pupil in the sense of a young student. The use of this root in naming the pupil of the eye is said to have arisen from the small reflection of objects seen over the opening of the iris.

pylorus Gr. pyloros = gatekeeper; from pyle = gate, and ouros = a guard. The muscular ring of the pylorus guards the outlet of the stomach.

pyriform L. pirum = a pear, and forma = shape or form. Hence describing any pear-shaped structure.

quadratus L. quadratus = a square in shape. Applied to the several square muscles.

radius L. radius = spoke of a wheel. Found in the writings of Galen applied to the bone now so named.

rectum L. rectus = straight. Galen so named the terminal bowel because he found it straight in other animals.

rectus L. rectus = straight.

renal L. ren = kidney. It is the adjective form of ren.

retina L. rete = a net. This is probably the correct derivation, although there is no truly net-like structure in the retina. It probably came about as follows: Galen applied to this structure the Greek word amphiblestron, which had two meanings - a surrounding coat and a fisherman's net. He used the word in the first sense; but when it was translated into Latin, the translator chose the second meaning.

retroversion L. retro = backward, and versio = turning. Therefore a turning backward.

rhomboid Gr. rhombus = a lozenge, and eidos = resemblance. Rhomboid denotes a parallelogram with oblique angles and unequal sides. The rhomboid muscle is so named because of its shape.

risorius L. risor = one who laughs. The risorius muscle draws the angle of the mouth outward.

sacrum L. sacer = sacred. Sacrum is the neuter form of sacer, and was applied to this pelvic keystone because this bone was thought to survive after death and form a part of the body after resurrection.

sagittal L. sagitta = arrow. Use to mean (1) shaped like an arrow, (2) straight, and (3) running in an antero-posterior direction.

salpinx Gr. salpinx = a trumpet. this is one of the words which the Greeks adopted from Crete. Applied to structures shaped like a trumpet or tuba. The combining form, salpingo-, appears chiefly in gynecological terms.

saphenous Gr. saphenes = clear or manifest. also possibly from Arabic, al-safin = hidden, because the vein is available for blood draws in only a small part of its course.

sartorius L. sartor = a tailor. This muscle was so named because it is employed in squatting in the usual position of an old fashion tailor, with the legs crossed.

scalenus Gr. skalenos = uneven.

scaphoid Gr. skaphe = a skiff or anything similarly hollowed out, and eidos = resemblance. The scaphoid bone is of this shape.

scapula L. scapula = shoulder blade. In ancient times it was used in the plural to mean "the back".

sciatic L. sciaticus; originally from the Gr. ischion = the hip. Hence the term applies to anything near, or pertaining to, the hip.

sclera Gr. skleros = hard. It is because of its relative toughness that the outer layer of the eye is named the sclera.

sella turcica L. sella = saddle, and turcica = Turkish. A descriptive name for the saddle-shaped prominence of the sphenoid bone. The pituitary gland sits in this saddle.

serosa Mod. L. sersus = membrane giving off serum.

serratus L. serratus = notched, from serra = a saw. The serratus muscle has a jagged edge.

sesamoid Gr. sesame = an herb, and eidos = resemblance. Galen suggested this name for these little bones because they resembled the seeds of sesame.

shoulder AS. sculdor = shoulder.

sigmoid Gr. sigma = the Greek letter S, and eidos = resemblance. In earlier times the letter sigma was written as a single curve (now the letter C), which better explains this name for a curved part of the large bowel.

sinus L. sinus = a bay or anything hollowed out.

skeleton Gr. skeletos = dried up.

skin AS. scinn = skin.

skull AS. skulle = a bowl.

socket OE. socket = spearhead; from OF. soc = ploughshare. Later the meaning was transferred to mean a sheath or holder, the hollow into which something fits.

soleus L. solea = sandal, sole of a shoe, and a flat fish. The sloeus muscle is not in the sole, but is flat. For the sole of the foot, see PLANTAR.

soma Gr. soma = the body.

sphenoid Gr. sphen = wedge, and eidos = resemblance. The sphenoid bone is wedge-shaped.

sphincter Gr. sphinkter = a band; from sphingein = to bind.

spine L. spina = a thorn. Hence any sharp process of bone; later applied to the vertebral column and to the spinal cord

splanchnic Gr. splanchna = viscera or internal organs. This adjective is applied, for example, to the nerve supplying the viscera.

spleen Gr. splen = spleen, perhaps originally related to splanchna = viscera. In Latin this root became lien afer losing its initial sp. From splen, of course, comes splenic and the combing form spleno-.

squamous Gr. squama = fish-scale.

stapes L. stapes = stirrup. The smallest of the three ossicles resembles a stirrup.

stenosis Gr. stenos = narrow, -osis = condition. Applied to any narrowing of tubular structure, such as an artery, heart valve, or the esophagus.

sternum Gr. sternon = the male chest, until Galen limited its meaning to the breast bone.

stomach Gr. stomachos; originally derived from stoma = mouth, and for a time applied to the esophagus, with the thought that the gullet is the mouth of the stomach.

styloid Gr. stylos = pillar, and eidos = resemblance. Applied to the styloid process of the temporal bone.

sulcus L. sulcus = groove or furrow.

supinator L. supinare = to turn palm upward or on the back.

supra L. supra = above.

sustenaculum L. sustenare = to support (from sub = under and tenere = to hold), and -culum = a diminutive suffix. Applied to a projection from the os calcis which supports the talus.

suture L. sutura = a sewing or seam. Hence a suture in the anatomical sense, as between the bones of the skull

sympathetic Gr. syn = with, and pathos = suffering.

symphysis Gr. symphysis = a growing together; from syn = with, and physis = growth. Hence a union, but not a true joint.

synapse Gr. syn = together, and haptein = to touch.

syndactylism Gr. syn = together, daktylos = finger. A congenital anomaly in which the fingers are webbed together.

systole Gr. syn = together, stellein = to draw. Hence to draw together or to contract, as the heart does in systolic contaction.

tachycardia Gr. tachys = swift or fast, and kardia = heart.

taenia Gr. tainia, and later L. taenia = a ribbon, tape, or fillet. This term, used as the name of a genus of tapeworms, is also applied to the longitudinal muscle of the colon.

talipes L. talipes = club foot; from talsus = ankle, and pes = foot.

talus L. talus = ankle.

temporal L. temporalis = pertaining to the temples.

tendon L. tendo = a tendon; from tendere = to stretch.

tensor L. tensor = stretcher or puller.

thenar Gr. thenar = palm of the hand. Later limited to the radial of the thumb side of the palm.

thorax Gr. thorax = chest.

thymus Gr. thymos = a warty growth.

thyroid Gr. thyreos = a shield, and eidos = resemblance. From a figure-of-eight shield used by the Greeks.

tibia L. tibia = a flute; from a resemblance in shape.

tongue AS. tunge = tongue.

tonsil L. tonsilla = tonsil.

tooth AS. toth = tooth.

trachea Gr. tracheia = rough. Tracheia bears the feminine ending to agree with arteria. The Greeks believed that arteries contained air; Aristotle called the arteries smooth, while he named the windpipe "rough artery".

tragus Gr. tragos = a male goat. This part of the external ear received this name because of the hairs which grow there, like a billy goat.

transverse L. transversus = crosswise. used, for example, of a myelitis extending across the cord.

trapezius Gr. trapeza = a table. Originally a contraction of tetrapeza = four-legged.

triceps L. tri = three, and caput = head.

tricuspid L. tri = three, and cuspis = point. Hence applied to the heart valve that has three leaflets.

trigone Gr. trigonon, from tri = three, and gonia = angle. Used of several triangular areas, but especially the triangle in the urinary bladder.

trochanter Gr. trochanter = a runner; derived from trochos = a wheel. The name of the processes below the neck of the femur.

trochlea L. trochlea = pulley.

truncate L. truncus = stem or trunk. A cut across like a tree stump.

tubercle L. tuber = a knot or collection, and -culum = a diminutive suffix.

tuberosity L. tuber = knob or localized collection, and -osity = condition.

tunica L. tunica = shirt or covering.

tympanum Gr. tympanon = a drum. Applied to the eardrum.

ulna L. ulna = elbow, forearm.

uncus L. uncus = a hook. Applied to several hook-shaped structures in the brain.

ureter Gr. outeter, from ouron = urine, and the suffix -ter, denoting the instrument. Applied to the upper urinary canal.

uterus L. uterus = womb. Its relationship to uter = bag of goat skin, has been suggested.

uvula L. uva = a grape, and the diminutive suffix -ula. Hence a little grape.

vagina L vagina = a sheath. From its shape and function.

vagus L. vagus = wandering. Hence of widespread distribution. Our English words vague and vagrant come from this same source.

varus L. valgus = bowlegged. The word is used in the term coxa valga to denote an abduction of the thigh due to deformity of the neck of the femur. In contrast, genu valgum has been used to mean knock-kneed.

vermiform L vermis = worm, and forma = form. Its use is not limited to the vermiform appendix.

vertebra L. vertebra = a joint of the spine; from vertere = to turn.

viscera L. viscera, plural of viscus = an internal organ. More often used in the plural form.

vitreous L. vitreus = glassy. Applied to the vitreous humor of the eye. The word comes originally from vitrum = glass; and from this comes the phrase in vitro, meaning in a glass receptacle, as contrasted with in vivo, in the living body.

volar L. vola = palm or sole.

vomer L. vomer = ploughshare. The bone named vomer suggests a ploughshare by shape.

xiphoid Gr. xiphos = sword, and eidos = resemblance. The name of the tip of the sternum.

zonula L. zona = a girdle, belt, or zone, and the diminutive suffix -ula.

zygoma Gr. zygoma = bolt or bar, related to zygon = a yoke. Applied to the cheekbone because of its shape.