The Anatomy Word of the Day will return on January 2nd, 2008.

Happy holidays everyone!


From the archives:

Clavicle, the collarbone: the slender, sigmoid-shaped bone that links the manubrium of the sternum to the acromion of the scapula. From the Latin clavicula, ‘small key’, a translation of the Greek kleidion.

The word was coined in the 12 century by the translators of the 10 century Persian physician Abu Ali Sina (his name was often latinized as Avicenna) whose works were a mainstay of European medicine the until the mid-17th century. Ali Sina used alchiab, ("the key") for collarbone, this from his own translations of Latin anatomy treatises from ancient Rome.

Ala Sina's translators returned to the Latin, renaming alchiab the clavicula, the diminutive of clavis (key).

But why key? A common tale is that the Romans likened the collarbone to a clavis simply because of similarity in appearance. However, it was probably not Roman door keys, which do not resemble clavicles, that were alluded to but rather S-shaped lift-latches, a primitive type key type first seen the Iron Age and common in Rome.

A Roman lift-latch ca 350 BC:
designed to allow a door-latch

to be lifted through a hole in the door.
It acted as a simple key. England, ca 350 BC

It has also been suggested that the relationship of the clavicle to a key is metaphorical, given that the bone "locks" the shoulder girdle to the trunk. Of course neither of these explanations are mutually exclusive, as the key shape lends itself nicely to the metaphor.

Perhaps though, "key" was a mistranslation by Ali Sina: yet another explanation is that the name comes from the resemblance of the bone to a toy, a curved stick called a clavicula or clavis trochi used by Greek and Roman children to roll, or trundle, a hoop.

A clavicula or clavis trochi, a child's toy for trundling a wheel in ancient Greece and Rome; from the Dictionary of Greek and Roman Antiquities, 3rd Edition by Anthony Rich. 1874

A minority view holds that the term has nothing to do with keys or trundles or metaphors but rather is named for the clavicle's resemblance to the sinuous tendrils of some plants. The Latin word for tendril is also clavicula.

The original Greek kleidion lives on in sternocleidomastoid muscle

Anatomically unrelated: the clavichord was the first keyboard instrument.


From the archives:

Finger comes unaltered from Old English (i.e. Anglo-Saxon). Indeed, the word is found, spelling unchanged, in most of the Germanic languages (e.g. German, Swedish, and Danish); The Dutch get by with vinger.

Each of the fingers have had their own Latin names. Some examples are given in the Aberdeen Beastiary, published in Scotland in the 14th century. (A bestiary is a collection of descriptions of all sorts of animals - some real, some imaginary - and other features of the natural or unnatural world.) From the Bestiary:

  • "The [first] finger, index, is also known as salutaris or demonstratorius, the greeting or indicating finger, because we generally use it in greeting, showing or pointing."
  • "The [second, middle] finger is called impudicus, lewd; it is frequently used to express the pursuit of something shameful."
  • "The [third] is the ring finger, anularis, because it is the one on which a ring is worn. It is also called medicinalis, the medical finger, because it used by physicians to smear on ground-up salves."
  • "The [fourth] finger is called auricularis, because we scrape our ear, auris, with it."
The image “http://www2.jpl.nasa.gov/galileo/images/finger.gif” cannot be displayed, because it contains errors.
A digital display: Galileo Galilee's impudicus finger is on exhibit at the Museo di Storia della Scienza in Florence, Italy. www2.jpl.nasa.gov/galileo/finger.html


From the archives:

Malar - relating to the cheek. From the Latin mala, cheek. The only remaining use for the word in anatomy is seen in "malar lymph nodes". The "cheek bone" was once called the malar, but the Terminologia Anatomica now only recognizes zygomatic bone.

Mala is probably derived from malus, Latin for apple; see the photo below for some evidence as to why apples and cheeks have been linked.

Definitely derived from malus is malic acid, first isolated in apple juice in the 18th century and responsible for the tart taste of apples, grapes, and rhubarb, among other foods.


From the archives:

Fascicle comes from fasciculus, the diminutive of the Latin word for bundle, fascis. The term is used to describe either bundles of axons within nerves or bundles of muscle cells within muscles (fascicles form the visible grain of a muscle as well as the strings of pot roast that may get stuck between your teeth).

Six fascicles, each a bundle of axons, seen in a cross-section of a small nerve about 1 mm in diameter.
From Wikipedia.com

In ancient Rome, the fasces (plural of fascis) was the name given to the official insignia of authority: an axe suspended over a bound bundle of birch rods. Through the centuries, fasces became a symbol for solidarity as well (an allusion to the bundle), eventually giving rise to the Italian word for a "united political group", fascio. One such organization, founded in Italy in 1919 by a newspaper editor named Benito Mussolini, was the Fasci di Combattimento, a collection of disgruntled Italian citizens that used the fasces as its logo.

In 1921 Mussolini and his group, by then a full-blown political party, had gained total control of Italy, in part through brutal suppression of the opposition. In the same year the English press, in reference to Mussolin's Fasci organization, began calling members of the movement fascists and its ruthless philosophy fascism. The names stuck.
The image “http://upload.wikimedia.org/wikipedia/commons/a/a6/Fasces.png” cannot be displayed, because it contains errors.
A ancient Roman fasces in a bas-relief at the Matte Palace in Rome. From A Dictionary of Roman Antiquities, by Antony Rich, Appelton, 1874.

A fasces was on the US dime from 1916-1945.


Coccyx, the tail bone, comes from kokkyx, Greek for cuckoo. One of the oldest words in anatomy, it was coined around 300 B.C. by Herophilus who, it is said, was inspired by the cuckoo's bill (probably that of the common cuckoo, Cuculus canorus). However, he was more likely taken by the anterior portion of the cuccko skull, which bears a greater resemblance to the coccyx than just the bill alone (see the photos below).


A more fanciful explanation of the link between cuckoo and coccyx was provided in the early 17th century by the French anatomist and surgeon Johann Riolan, who inexplicably insisted that the sound of flatus emanating from the coccygeal region was reminiscent of the call of a cuckoo and thus was the inspiration for Herophilus. Never mind that neither the male nor the female of any cuckoo species has a call that you'd confuse with flatulence (indeed, the classic sound of the cuckoo clock was patterned after the call of the male common cuckoo). Perhaps the professeur simply had a talented friend.

Nonetheless, the coccyx has been called the "whistle bone" for its proximity to the source of digestive tract toots.

Unrelated but interesting: The word "cuckold" (a man whose wife has cheated on him) also comes from cuckoo, derived from the female's nasty habit of laying eggs in nests not her own and thus tricking other birds into raising her young. Likewise, a cuckold may raise children that aren't his.

Image credits
coccyx from
The common cuckoo from
cuckoo skull


From the archives:

Achilles tendon: the common tendon of the gastrocnemius, soleus, and sometimes the plantaris muscles; also known as the calcaneal tendon. It attaches to the posterior portion of the calcaneus or heel bone.

The name comes indirectly from Greek mythology: After receiving a prophecy that her young son, Achilles, would die in battle, the goddess Thetis dipped him into the magical, protective waters of the river Styx. However, she held him by his heel which was not immersed and thus remained vulnerable. Years later, as luck would have it, Achilles was fatally wounded during the Trojan War: a poison arrow in the back of the foot, a region henceforth known as Achilles heel (and so, metaphorically, an "Achilles heel" is a seemingly insignificant but in fact critical weakness).

It wasn't until 1693 that the term Achilles tendon appeared (chorda Achillis in the original Latin), so named by the resourceful Dutch anatomist Philip Verheyen while dissecting his own amputated leg.

Thetis dipping Achilles in the river Styx.
Sculpture by Thomas Banks (1735-1805)
Victoria and Albert Museum, London

Philip Verheyen dissecting his Achilles tendon. Artist: anonymous; from the collection of Pieter Deheijde, Amsterdam


From the archives...

Sphincter was first used by Galen in the 2nd century, probably as an allusion to the talented constrictor that was the Sphinx of Greek mythology. A chimera with the head of a woman and the body of a winged-lion, and who received her name from the Greek sphingo, "I strangle", the Sphinx sat outside Thebes and demanded that all passersby answer her riddle: "Which creature travels in the morning on four feet, at noon on two, and in the evening upon three?" She strangled anyone unable to answer. Oedipus finally provided the correct response.

A fourth century BC kylix
from the Vatican Museum showing
Oedipus with the Sphinx


Note that the Grecian Sphinx is not the same as the sphinxes of Egypt: The Greek name "sphinx" was inexplicably applied some 2600 years ago to an Egyptian chimeric lion, even though it is wingless and has the head of a man not a woman. The original Egyptian name of this creature is unknown. The most famous of the Egyptian sphinxes is the Great Sphinx of Giza.


Colostrum, the first milk secreted by the mother after giving birth, comes from the Latin colostra, a word with the same meaning used by the Romans. Colostra appeared in English in the late 16th century, joining the equivalent terms of "beestings" and "green milk" (both of which, unfortunately, having since disappeared from the language).

By the early 19th century, the spelling had changed to colostrum.

Aulus Plautius, the politician and general who lead the Roman conquest of Britain in 43 A.D., used colostra as a word of endearment: Meum mel, meum cor, mea colostra: "my honey, my heart, my colostra".


Cornea, from the Latin, cornu, animal horn, and corneus, horny (i.e., tough and hard like a horn).

It seems strange for the cornea, the transparent and seemingly delicate anterior surface of the eye, to be etymologically related to an animal horn but it was recognized long ago that the structure,
when dissected, is surprisingly hard; thus its "horny" nature.

The stratum corneum, the name given to tough outer layer of the skin, also comes from cornu, as does the corniculate cartilage of the larynx (literally, corniculate means "shaped like a little horn").

Some other words derived from cornu include Capricorn (literally, a goat's horn), cornucopia (the horn of plenty), and cornet (which, like all musical horns, can trace its ultimate ancestry back to the animal horns used as musical instruments by prehistoric humans).

Note that although the coronoid processes of the mandible and ulna have a shape reminiscent of animals horns, "coronoid" is derived
not from cornu but from korone, Latin for crow, or korax, Latin for raven. Charitably, these structures also resemble a corvid's beak, though the Greeks often used korax for many structures with a slightly hooked or pointed tip, such as the handles of their doors (see coracoid).


Foramen is taken directly from the Latin word for hole, foramen, which in turn comes from the Latin forare, to pierce.

There are 40 named foramina in the Terminologia Anatomica; most are in the skeletal system and the majority of those are in the skull.

Perforate is also derived from forare.


Ankle comes from the Latin angulus (little corner or angle; hook-like) for the bend between the foot and the leg.

Angulus may also be the source for the Latin word
angeion, small blood vessel, perhaps in reference to the frequent branching of such. Angeion gives us the combining form angio-, blood vessel, as in angiogram, angiogenesis, and angiotensin.

Non-anatomical tidbits: another word derived from angulus is Angul, the name given to the hook-shaped bit of land in what is now the Netherlands. From this area came the Angles, who along with the Saxons and Jutes, formed the Anglo-Saxons, the people who inhabited the land now called England in the 500 years prior to the Norman invasion of 1066.

An angler, one who fishes (with hooks), is also derived from angulus.

Picasso, Foot, 1894, Charcoal and crayon on paper, Museu Picasso, Barcelona, Spain.


Bile comes from the Latin word for bile, bilis.

The Greek word for bile is cholé and is an oft used combining form: a cholecystectomy is the removal of the gall bladder, literally, "removal of the bile bag" (cyst is derived from the Greek kystis, bag or pouch). Cholecystokinin (CCK) is a hormone that stimulates gall bladder contractions, among other functions (-kinin comes from the Greek kinein, to move or stimulate).

To the ancient Greeks and Romans and other believers in the "four humors", melancholy, from melos (Greek for black) and cholé, was thought caused by an excess of "black bile". The word choleric, meaning easily angered or annoyed, stems from the notion that excessive "yellow bile" was responsible for one's ill-temper. Bile, in its non-physiological sense, still refers to a choleric disposition (as in "full of bile") and bilious, from bilis, refers to someone who is peevish or, logically enough, ill-humored.

Gall comes from the Anglo-Saxon word for bile, galla; thus the "gall bladder", the organ that stores and concentrates bile.


Dens, a tooth-like process on the axis (the second cervical vertebra). From the Latin word for tooth, dens.

An alternative name for the dens is odontoid process (from the Greek odous, tooth, and -oeides, shaped). The term is no longer recognized by the Terminologia Anatomica, but is still firmly entrenched in the anatomical lexicon.

Other words related to dens: dentist, dentate (having a toothed or serrated edge), trident (a three-pronged, or toothed, spear), dandelion (from the French dent de lion, "tooth of the lion", referring to the dentated edge of the plant's leaves), and dentine (also dentin), the bone-like tissue that makes up the bulk of the tooth.

Anterior view of the axis. The oval facet visible on the dens articulates with the anterior arch of the atlas. wheelessonline.com


Medulla, Latin for marrow. Because of its derivation from the Latin medius, middle or core, medulla often implies a deep region within a structure, such as the renal medulla or the medulla of the adrenal gland.

Medulla was the word Vesalius used for the spinal cord, inspired perhaps by the name the Greeks favored: myelos rachites, "marrow of the spine". Indeed, the soft neural tissue of the spinal cord within the vertebral canal of the spinal column does remind one of marrow present in the hollow shaft of a long bone (in the space appropriately called the medullary cavity).

"Marrow" still appears in many English dictionaries as an alternative name for the spinal cord, though this definition has been long since discarded by anatomists.

In spite of being part of the brain, it is the spinal cord that's referred to in medulla oblongata. The term was first used by the German anatomist Lorenz Heister in 1740 and it's not clear why: its meaning does not make a lot of sense ("oblong-shaped spinal cord" or as some translate it, "rather long spinal cord") and there had been a reasonable term in use earlier, the medulla prolongata, which does make sense ("spinal cord extension"). Nonetheless, medulla oblongata became established while medulla prolongata disappeared.

Heister's original use of the term was for the entire brain stem. In 1750, the Swiss anatomist Albrecht von Haller restricted the use to its present meaning: the thumb-size segment of brain stem continuous with the spinal cord. (Haller, considered the father of modern physiology by many medical historians, named the Graafian follicle in honor of Dutch anatomist and poet Reinier De Graaf who discovered the ovarian follicles (but thought they were eggs)

Albrecht von Haller (1708-1777) www.ilmyco.gen.chicago.il.us


Chiasma, a "crossing", from the Greek letter for X, chi (pronounced "ki", rhyming with "sky").

The term was first used by first century Romans for the X-shaped crossing of the optic nerves just anterior to the pituitary. For some reason the word fell out of favor with subsequent generations of anatomists; not until the late 1500's was it revived, reentering the anatomical lexicon for a permanent stay (although "optic chiasm" is now preferred over "optic chiasma" by about a 4 to 1 ratio; both terms are recognized by the Terminologia Anatomica.)

True to its derivation, chiasma is pronounced with a hard ch, as in "chronicle".




From the archives:

Mitral is derived from the Latin mitra, girdle or turban, which gave rise to mitre, the ceremonial head-dress first worn by Roman Catholic bishops. Subsequently the hat was adopted by bishops of the Anglican, Episcopal, and some of the Christian orthodox churches.

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A 15th century bishops' mitre on the left, a present-day mitre on the right, and in the middle, a 16th century-style mitre from the time of Vesalius.
Adapted from the Catholic Encyclopedia www.newadvent.org

21st century mitre.

The mitral valve of the heart, positioned between the left atrium and left ventricle, was so named by Vesalius in the 16th century because its two parallel cusps (flaps) resemble of the paired, pointed "horns" or cornua of an (upside-down) bishop's mitre. Thomas Henry Huxley, "Darwin's bulldog" and the person who coined "agnostic", would give his students this mnemonic to remind them the valve was on the left: "a bishop is never in the right."

The mitral valve is also known as the bicuspid valve or the left atrioventricular (AV) valve. The Terminologia Anatomica no longer lists bicuspid.
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Upside down view of the mitral valve showing its mitre-like appearance. From top to bottom, note the papillary muscles, the chordae tenidneae, and two cusps of the valve www.lionden.com


From the archives:

in anatomy, is an adjective meaning "related to the chin". It comes from the Latin word for chin, mentum.

Its use is seen in the mentalis, a muscle covering the tip of the chin, and the mental foramen, a small passageway found near the chin on each side of the mandible through which the mental artery, vein, and nerve pass.

Across all cultures it is common for people to touch their their chins as they ponder, but mental as in "mental images" comes from mens, Latin for mind, and not from mentum. However, as mentum is so closely linked to mens through our behavior, some etymologists believe (albeit without evidence) that both words are somehow etymologically related.

The Thinker by Auguste Rodin: engaged
in two types of mental activity.


The Anatomy Word of the Day is taking a Thanksgiving break. The next few days' worth of entries are from the archives.

(plural, fornices), comes directly from the Latin word for a vault, i.e., a small room with an arched ceiling. Often the term was by the Romans in specific reference to rooms occupied by slaves or the poor. Street prostitutes were known to provide their services in fornices; hence the word "fornication".

The use of fornix in anatomy includes:
  • The left and right fornices of the brain's limbic system, formed by white matter tracts that arch over the diencephalon,
  • The vaginal fornix, the vaulted space in the vagina that surrounds the cervix of the uterus
  • The gastric fornix, a term used in radiology for the internal arch of the fundus.

A series of fornices in Roman ruins, Gaeta, Italy, with the front walls and doors long gone. Modifed from A Dictionary of Roman Antiquities, by Antony Rich, Appelton, 1874.


Afferent: moving towards something; used in reference to blood, lymph, or nerve impulses. Derived from the Latin afferre, ‘bring towards’.

Afferent arterioles in the kidney convey blood towards the glomerular capillaries. Afferent neurons carry impulses towards the central nervous system (and thus are always sensory in nature). Afferent lymphatic vessels carry lymph into lymph nodes.

Afferent arterioles ('a') carrying blood to glomerular
capillaries; arrow indicates direction of flow.

(Adpated from bicmra.usuhs.mil/)

The opposite of afferent is efferent (from the Latin efferre, to carry off) which refers to movement away from a reference point. Efferent arterioles carry blood out of the glomerular capillaries. Efferent neurons carry impulses from the central nervous system (and thus are motor). Efferent lymphatic vessels carry lymph out of lymph nodes.

An easy mnemonic: Afferent Arrives, Efferent Exits.


Fossa, from the Latin fossa, ditch or trench.

Anatomically, a fossa is a depression or hollow. It is the most commonly used descriptive term in anatomy, seen in 64 different structures in the Terminologia Anatomica; the most frequently cited structure (on the Internet at least) is the iliac fossa, followed by the popliteal fossa, fossa ovalis, mandibular fossa, and olecranon fossa.

A word that shares Latin roots with fossa is fossil, coming from the Latin fossalis, dug up. Fossa and fossil ultimately stem from the Latin verb fodera, to dig.


Pancreas, from the Greek pan, all, and kreas, flesh.

The original use of the term, dating to at least the time of Homer in the 8th century BC, was for any edible meat or meat-like substance. Herophilus, the 3rd century BC Greek physician out of Alexandria, was the first to use the word for the organ, naming it for its meaty appearance.

"Sweetbread" is the traditional dinner-table term for either the pancreas or thymus gland taken from calves or lambs; the culinary pancreas has also been called stomach sweetbread. Today it is typical for only the thymus to end up in a recipe while the pancreas is more likely to be sold to pharmaceutical firms.

Another word derived from kreas is creatine, the energy-storage molecule first found in skeletal muscle.


Fimbria, direct from the Latin fîmbria, the ornamental fringe on the borders of clothing, cloth napkins, etc.

The fringe on the border of the uterine tubules were first called fimbria in the 17th century by the Dutch anatomist Reinier De Graaf (the man who coined "ovary" and discovered that ovaries produce eggs, and in whose honor the Graafian follicle was named).

Julius Caesar favored fimbria on the sleeves of his tunics (interesting as this was considered an exclusively feminine affectation by both the Greeks and Romans).

An engraving of a Roman dinner napkin with fimbria; from a painting found in Pompei.
From A Dictionary of Roman Antiquities, by Antony Rich, Appelton, 1874.


Lumen, straight from the Latin for light, lumen. The Romans also used the term for the aperture of windows, particularly round ones, and it once was the name given to the pupil of the eye.

Its anatomical usage now is reserved for the space inside a tube, e.g. an arterial lumen, a definition probably stemming from a tube's round opening when seen in cross section, or perhaps from the light seen through a tube if opened on both ends.

In physics, a lumen is a unit of brightness. A 100-watt incandescent light bulb generates about 1600 lumens.

Other words from lumen include luminary, luminescence, illuminate.


Jejunum, from jenunus, Latin for empty or hungry: This portion of the small intestine, the 3 feet or so between the duodenum and ileum, is typically empty when dissected, perhaps as a result of residual peristalsis in the moments after death or because most will not have eaten in the hours before death.

The original name, given by Galen, was nestis, Greek for fasting. Later the term was translated into Latin as jejunum.

Also derived from jenunus is the word jejune, something insubstantial or devoid of interest, such as the jejune comments of politicians.


Canine, aka the cuspid, the tooth between the lateral incisor and first bicuspid. It gets its name from canis, Latin for dog, which in turn comes from the Greek word for dog, kynos. The Greeks were indeed the first on record to note the tooth's superficial resemblance to the corresponding dog tooth, in particular the relatively long, often sharply pointed cusp.

The upper canines are sometimes called the "eye teeth", perhaps because their roots can extend close to the lower margin of the orbit during their development in the maxillary bones. For reasons unknown, the lower canines have been called the "stomach teeth", a phrase of uncertain origin that has all but disappeared.

Most dentists and dental hygienists freely use both canine and cuspid (perhaps preferring the former since canine would be a more familiar term to the majority of their patients). Among anatomists however the preferred term is cuspid (from the Latin cuspis, point); canine is not listed in the Terminologia Anatomica.

The crown of a developing canine (arrow) in the skull of a child approximately 9 years of age.
Photo by C Carpenter


Navicular is derived from the Latin navicula, little boat (the diminutive of navis, boat).

There are two bones in the skeleton commonly called the navicular, one a carpal and the other a tarsal; both are named for their resemblance to little boats. However, the Terminologia Anatomica only recognizes the tarsal as the navicular; the carpal is more properly called the scaphoid (from the Greek skaphe that, like navicula, also means a small boat and from which comes the word skiff).

Other words derived from navis include navigation and navy.

The right navicular of the foot.
The concave, proximal surface (the top of the boat) articulates with the head of the talus. Its stern is on the foot's medal aspect.
Photo by C. Carpenter.

Modified from www.healthcareers.umn.edu


Dartos, the smooth muscle layer just deep to the skin of the scrotum; from the Greek, dartos, skinned or flayed.

The term was first used by Greek physicians for any anatomical preparation in which the skin had been removed. The first-century Romans, for reasons unclear, began using the term only for the muscle seen after removal of the skin of the scrotum; the name stuck.

When exposed to cold the dartos contracts. The scrotal skin wrinkles, the exposed surface area is reduced, and heat loss is minimized. Thus the muscle helps to regulate the all-important testicular temperature (and working with the spermatic cord's cremaster muscle which contracts to pull the testes towards the warm abdominal wall).

In females, a homologous muscle called the "dartos muliebris" (muliebris is Latin for "womanly") is found beneath the skin of the labia majora and is much less developed than the male counterpart. Its function probably rivals that of male nipples in importance.


Larynx comes directly from the Greek larynx which in turn is from larungao, Greek for scream or bellow. The earliest recorded use of the term was by Aristotle in the 4th century BC.

Commonly known as the voice-box, the larynx houses the vocal folds; it is the only component of the respiratory system located entirely within the neck.

"Larynx" is probably the most misread and thus most mispronounced word in anatomy. The correct pronunciation is "lair-rinks", not the oft-heard "lair-niks". I've had the disconcerting experience of being treated by health professionals who said lair-niks, immediately raising the perhaps unfair but easily avoidable question: What else don't they know?

Anterior view of larynx, trachea and bronchial tree
Andreas Vesalius
De Humani Corporis Fabrica, 1543, p.151


Omentum. The earliest recorded use of the word was by the Roman writer Celsus in the first century B.C. who referred specifically to the abdominal structure now called the greater omentum. The term has always been employed in an anatomical sense; there is no other known use.

Its derivation a mystery and Celsus left no clues. It may come from operimentum, Latin for the cloth used as a bed covering in ancient Rome much as the greater omentum covers the small intestine (the lesser omentum encloses the bile ducts and hepatic vessels). Others suggest it comes from opimus, Latin for plump, which would be an allusion to the fatty nature of the omenta. Or the term may come from the Latin omen, given the practice among some of the ancient soothsayers to prophesy using the entrails of sacrificed animals (and employing, as it were, a gut instinct as to what specific omens the visceral mess may signify).

The beer belly in men is due primarily to accumulation of greater omentum fat (with mesentery fat sometimes contributing). In women, abdominal fat is more likely to accumulate subcutaneously.



Lens, from the Latin, lens, the lentil bean.

The lens of the eye was so named by the Romans in the 1st century B.C. because of its resemblance to a lentil bean in shape and size.

The diameter of the human lens at birth is about 6 mm. By the time one is in their mid-sixties the lens will typically have reached a maximum diameter of around 9 mm. (The average diameter of a lentil is 6-7 mm.)



Malleus, Latin for hammer; the auditory ossicle that articulates with the the incus medially and the tympanic membrane laterally.

As the incus (Latin for anvil) does bear a striking resemblance to anvils going back to ancient Rome, you'd be justified in assuming that the naming of the malleus was inspired by the blacksmith's hammer. Indeed, the bone does have a long handle and a head that articulates with the incus, just as the hammer of a blacksmith should. However, it resembles not the hammer of the smithy but the hammer of the priest, used to stun oxen prior to sacrifice; butchers used it too. This tool was large and heavy, requiring two hands and not an obvious inspiration for the name of one of the smallest bones of the body. However, it had a distinctively round head like that of the ossicle and thus the bone was so designated as the malleus.

The shape of the sacrificial hammer may also explain the rather mysterious naming of the lateral malleolus
and medial malleolus, the "little hammers" of the ankle that are so much larger the malleus of the ear. These rounded bony processes were probably given their name because they reminded Vaselius, who first used the term anatomically, of small versions of the large, round head of a malleus.

Other words derived from malleus include mallet and malleable, the latter in reference to metals such as gold that could be molded with hammer blows.

The malleus; adapted from Anatomy of the Human Body; Henry Gray. 1918

A sacrificial malleus from ancient Rome, from An Illustrated Companion to the Latin Dictionary and Greek Lexicon, Anthony Rich. 1849


Prepuce, the loose sheath surrounding the glans of the flaccid penis or clitoris.

The word first appears as praeputium in the Latin of ancient Rome; the derivation of praeputium is a matter of debate, possibly originating from the Latin prae (before) and the Greek posthe (penis). Or, more interestingly, it may be related the the Latin puteo ("I stink") in reference to the noisome accumulation of smegma, the sebaceous secretion that would collect under the prepuce of a habitually underwashed Roman male (notwithstanding the Roman baths, which not did not become an integral part of Romanic culture until the 2nd century BC, a full 300 years into the Roman Republic).

It has also been suggested that prepuce stems from praeputare ("to cut away", related to amputaere). However, the Romans used praeputium long before they became aware of the Jewish rite of circumcision.

The prepuce is referred to as the foreskin in males and the clitoral hood in females (although this latter term is not officially recognized by the Terminologia Anatomica). Its superior surface is skin and its inner surface is a mucosa; is this sense its organization is not unlike that of an eyelid.

During sexual excitement the prepuce retracts, exposing the glans. Given its sexual sensitivity, it can play role the tactile stimulation associated with sexual pleasure.

In a sexually mature man, the surface area of the intact prepuce averages about around 100 square centimeters, about that of a 3x5 index card.
Michelangelo's David in the Accademia Gallery, Florence, Italy.
Photo by Ussaro Etneo



Malleolus, Latin for little hammer. Vesalius, in the 16th century, was the first to use the term for the rounded, bony processes on the distal fibula (the lateral malleolus) and tibia (the medial malleolus), often referred to as the "ankle bones" in casual conversation.

That Vaselius called these relatively large processes "little hammers" is a bit ironic, considering that one of the smallest bones in the body, the malleus of the middle ear, was given the non-diminutive Latin name for hammer (probably named by the Italian anatomist Alessandro Achillini, 1463-1512).
See malleus for a discussion of Vaselius's inspiration for coining the term malleolus.

30% of ankle fractures involve the malleoli, usually the lateral.



Orbit, as in eye-socket, comes from the Latin orbita, a rut or wheel-track, which in turn comes from orbis, circular as a wheel or disc. Thus is it not difficult to see how orbita became associated with revolving or rotating. The eye-socket came to be called the orbit in reference to the rotational movements of the eyeball within.

The first use of orbita in an anatomical sense came from a Latin translation of the Arabic texts of Abu Ali Sina (Avicenna), the 11th century Persian anatomist, by the 12th century Italian scholar Gerard of Cremona.


Glenoid, from the the Greek glene, socket, eyeball, or mirror, and eidus, shape.

The etymology of glenoid, as in the glenoid cavity of the scapula, is murky at best. The earliest recorded use of glene, by Homer around the 7th century BC, was for mirror. By a few hundred years later, perhaps because of the mirror-like reflections that can be seen in the pupil, glene took on the meaning of eyeball (or, as some maintain, just the pupil). Still later, the meaning shifted to socket, perhaps because of the association of the eyeball with the orbit, or eye socket, of the skull.

But why is the socket on the scapula called the glenoid cavity? It has been suggested that the inspiration for this usage was the mirror-like glistening of the relatively flat articular cartilage on surface of the cavity, harking back to the original use of glene for mirror, which, along with its other meaning of socket, provided a term with definitions doubly appropriate to the structure. The only problem with this convenient story is a complete lack of evidence in its favor, but no better explanation has been offered.

Galen, in the second century AD, was the first to employ the word for the scapular structure, but he kept the logic for the coinage to himself.

Anatomically unrelated: The name of the protozoan euglena comes from eu- (true) and, for some reason, glena (mirror, eyeball, pupil, socket -- take your pick)


Glomerulus, the spherical capillary tuft within the kidney, is the diminutive form of the Latin word for glomus, something wound into a ball, usually used in reference to yarn. These "little balls of yarn", of which there are about a million in a kidney with each serving a nephron, were discovered in 1666 by the preeminent Italian anatomist, Marcello Malpighi.

Malpighi also was the first to describe capillaries. His accurate observations of microscopic structure were amazing accomplishments given the primitive state of microscopy at the time.

Glomeruli were known as Malpighian bodies until 1788, when the term glomerulus was introduced by the Russian anatomist Alexander Schumlansky.

Non-anatomical words coming from glomus include conglomerate and agglomerate.

Marcello Malpighi (1628-1694)


Due to the craziness surrounding the wildfires in San Diego County, this blog is on temporary hiatus. Once the smoke clears, the embers stop blowing (and I can return to my house!) it will be back.


Endocrine, from the Greek endon, within, and krinein, to separate.

Friedrich Henle first recognised the presence of ductless glands in 1841, but "endocrine" was not used to describe these structures until the French physiologist Gustave-Edouard Laguesse coined the term in 1893.

Laguesse also named the islets of Langerhans, the pancreatic endocrine tissue that is the source of insulin and glucagon, among other hormones. They were so-called in honor of Paul Langerhans,
the German who first described islet anatomy in 1869 (but did not suggest any functions).

The word hormone was coined in 1905 by British physiologist Ernest Starling (from the Greek word for “excite", hormao.)

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Gustave-Edouard Laguesse



Intestines, from the Latin intestina, guts, which is from intus, within. The singular form, intestinus, means internal, domestic, or civil, and was a term used in governmental discourse by the ancient Romans.

The word clandestine (concealed, working in secret) comes from intestinus plus clam, Latin for secret

Intestina, in the anatomical sense, first appeared in a work by the great Roman anatomist Celsus in the first century B.C. (his book, De Medicina, was one of the first medical texts to be printed following the invention of the printing press 1500 years later).

Celsus also was the first to employ acetabulum and patella, among many other words of anatomy.

Aurelius Cornelius Celsus 53 B.C. - 7 A.D


Alimentary is an adjective that comes from the the Latin word for food, alimentum. The alimentary canal, also known as the digestive tract, is a tube extending from mouth to anus that's about 20 feet long (and typically longer in cadavers because of a loss of smooth muscle tone that occurs after death)

The Terminologia Anatomica, with futility, prefers alimentary system instead of digestive system.

The Indo-European root of alimentum is al, "to grow", giving rise to the Latin alere, "to nuture", from which developed alma mater (nourishing mother), alumnus (one who has been nourished), alimony (money for nourishment), and adult (one who has grown up thanks to nourishment; the "ul" in adult is derived from "al").


Pectoral, from the Latin pectus, breast. It's been suggested that pectus in turn comes from the Latin word for comb, pecten, because the ribs look like the teeth of a comb.

Pecten is the source of pectineus, a muscle originating from the pubic bone, either because the muscle's parallel fascicles resemble a comb or because pecten was once the name of the pubic bone. (Why the pubic bone should call to mind a comb is anybody's guess: one suggestion is that pubic hair was somehow reminiscent of wispy tufts of hair left on a comb.)

The comb-like parallel ridges of myocardial tissue seen within the right atrium and both auricles of the heart is called the pectinate muscle.


Aorta has an uncertain derivation. The first recorded mention of the word was by Hippocrates in the 5th century BC who used it to describe the trachea and its branches. Given the windpipe’s function, the term may have come from combination of the Greek aer (air) and tepeo (to hold).

Though he also subscribed to the Greek convention that arteries carried air, Aristotle, in the 4th century BC, was the first to apply the word to the vessel it is associated with today, inspired perhaps by a fancied resemblance to the arched sheath of an aorta, a large Greek knife with a curved handle.

Another candidate for Aristotle’s inspiration: aortemei, a Greek word meaning "suspend" (from aorter, a Grecian shoulder strap that things were hung from). Given all the blood vessels that branch to the viscera from the aorta, one can see how it may resemble a strap of sorts suspending the heart, kidney, stomach, and intestines.

Or it could it could be all of these; surely Aristotle loved puns just as much as the next guy.


Ischium comes from iskhion, the Greek word for the socket which receives the head of the femur (now called the acetabulum). The word was sometimes used simply for the hip joint.

Galen, in the second century A.D., divided the hip bone (os coxa) into the three bones we know today: the ilium, pubis, and the iskhion, which was later Latinized to ischium. These three bones fuse into the single hip bone during puberty.

The ischium receives the weight of the body when we are sitting: Though "we sit on the ish” is a mnemonic, the proper pronunciation is "ISS-kee-um" in honor of its Greek forebearer iskhion.

The unfused ischium of a two-year-old (bottom right).
Also seen are the pubis (bottom left) and ilium.


Collagen comes from the Greek kolla (glue) and gennao (I produce). A "producer of glue" is quite an apt characterization of collagen, at least metaphorically, as this most ubiquitous of intercellular structural proteins plays a fundamental role in holding the body together. However, the term was coined (sometime in the mid 1800's) not because of its role in connective tissues, but because it is the main ingredient of glues formed from the boiling of animal skin, tendons, and ligaments. (The oldest such glues yet discovered, in various artifacts found near the Dead Sea, date to 6200 BC.)

The word collage, meaning an artistic collection of images, printed matter, and other substances glued to a board, also comes from kolla.


Labrum comes directly from a word Latin for lip, labrum. The two ball-and-socket joints, the hip and the shoulder, each have a labrum: The glenoid labrum surrounds of the rim of the glenoid cavity in the shoulder and the acetabulular labrum surrounds the rim of the acetabulum in the hip. Both labia are composed of fibrocartilage and serve to deepen the sockets of their respective joints thus providing additional stability. The glenoid labrum plays the more important role of the two given the shallow form of the glenoid cavity as compared to the acetabulum.

Glenoid labrum tears are common athletic injuries , especially those sports involving overhand motions such as baseball and tennis.

Labium, directly from Latin word for the curved edge of a cup, labium, is used exclusively for the labium majus and labium minus (plural labia majora and labia minora) of the vulva.

The labrum, here labeled as the glenoid ligament. From Grey's Anatomy, 1909, via Wikipedia.com


Jugular comes from jugulum, a Latin word with at least three different meanings: the clavicle, the hollow in the neck just above the sternum, or the neck generally. Some dictionaries define the term as "relating to the throat", but "throat" in this context is in colloquial sense of "neck" as opposed to the anatomical throat, or pharynx, most of which is in the head behind the oral and nasal cavities.

The word comes from jugum, Latin for yoke, presumably because yokes are carried on the neck. Yoke is derived from jugum as well.

The jugular notch is the depression on the superior aspect of the manubrium at the hollow of the neck; it is also called the suprasternal notch. There are two other sets of jugular notches in the skeletal system, one on the temporal bones and the other on the occipital bone; together they form each half of the right and left jugular foramina of the skull, the point of origin of the jugular veins of the neck.

Using a yoke.
Modified from www.woodsurgeon.com


Nerve can be traced back all the way to the Sanskrit nauree, "string", circa 1000 BC, which gave rise to the Greek neuron, a term originally used by Hippocrates in the 5th century BC for various structures of a white, fibrous appearance, including tendons and ligaments ("sinews") as well as nerves; the word also was used for bowstring.

From neuron comes aponeurosis, first used by the Greeks for any broad, white, membrane-like tendon (apo is Greek for "derived from") and in use today for the same purpose. Examples include the epicranial aponeurosis and plantar aponeurosis.

In the 4th century BC, Aristotle restricted the use of neuron to the those structures we call nerves today. This was around the time the Greeks began to differentiate between the functions of nerves and sinews (they had come to realize that nerves were involved with muscle control, for example).

In one of the stranger quirks of anatomical etymology, Galen, in the 2nd century, came up with the word neuron, not from the Greek neuron, but from the Latin verb neuein, "to nod"; as he wrote: "nerves cause the limbs to nod and the joints to bend". Of course, he could have been simply enjoying a pun as well. However, it was the Greek neuron that gave way to the Latin nervus, which begat the French nerf, and finally the English "nerve".

Phrases such as "straining one's nerves" or "showing a lot of nerve" go back to the sinew notion of the word: strength, and from strength, courage.

Neuron, in the sense of a nerve cell, was coined in 1891 by the German anatomist Wilhelm Waldeyer, who first proposed the idea that the fundamental structure of nervous tissue was not that of a continuous web but rather discrete cellular units.

"Neuron" by Anna Vieth


Patella, directly from the Latin patella, a small dish or saucer. It is the diminutive of patera (from which we get pan). You'd think its anatomical namesake, the sesamoid bone of the quadriceps tendon also known as the kneecap, would thus shaped like a dish, but it is more triangular than round and has no concave surface. The term was introduced in its anatomical sense by Aurelius Celsus in the first century A.D.

True to its roots, an archaic name for the patella is kneepan.

A Roman patella. From the Dictionary of Greek and Roman Antiquities, by Sir William Smith, 1876
Celsus was a veritable mint of anatomical terminology coining, or at least bringing to light, abdomen, anus, cartilage, hernia, humerus, radius, scrotum, tibia, tonsil, uterus, and vertebrae, among others (see the classic text Origin of Anatomical Terms by Henry Alan Skinner for additional information). Interestingly, Celsus was not an anatomist or even a physician but a writer who produced a compilation of Greek and Roman medical texts that became one of the most influential medical books ever written. It had been lost to history until its rediscovery in 1443 in Milan, Italy, and was part of a larger encyclopedia of general knowledge he wrote that appears gone for good.


Hamstrings. Hamm is an Anglo-Saxon (i.e. Old English) word for the back of the thigh, which may be derived from an Old Teutonic word, ham, "crooked", that referred initially to the bend at the knee and later just the popliteal space behind the knee. The "strings" are the long, thin tendons of the muscles of the posterior thigh, specifically the semitendinosus and semimembranosus medially, and the lateral biceps femoris. The tendons can be easily felt on either side of the popliteal fossa (the "knee pit").

The "hamstrings" specifically refer to the tendons of the posterior thigh muscles but the practical usage of the word is in reference to the muscles as well.

The ham of the dinner table is typically the semitendinosus, semimembranosus, and biceps femoris of the pig, but anterior thigh and gluteal muscles may be present as well.


Liver, from the Anglo-Saxon word for liver, lifer. It seems logical that the etymology of the word is somehow related to "life" but no one knows for certain. It is interesting to note that the German word for liver is die Leber, and the German verb leben is "to live".

Hepar, Greek for liver, is the source of the combining form seen in words such as hepatic, hepatitis, and heparin (which was first isolated from the liver cells of dogs).

The Latin word for liver, jecur, doesn't show up anywhere in anatomy or medicine, or in any of the Romance languages. Strangely, the Spanish, French, and Italian words for liver (higato, foie, and fegato respectively) all stem from the Latin word ficatum, "stuffed with figs", whose link with the liver is through an ancient Roman dinner specialty: jecur ficatum: liver and figs.

It was long believed that the liver was source of the body's blood and lymph; when this was shown not to be true, the organ lost favor amongst anatomists and physiologists. Its stature was revived in the 19th century by the father of homeostatic theory, the French physiologist Claude Bernard, who recognized many of the organs vital functions; indeed we now know of at least 50 ways, as Paul Simon almost sang, to love your liver.

Cricoid comes from the Greek krikos (finger-ring) and -oedes (shape). The term was coined by the Romans in the first century.

  • It is almost universally stated that the cricoid cartilage, the most inferior component of the larynx, is so-named because of it's similarity to a signet ring (a ring with an engraved seal). However, the cartilage more closely resembles, and is more likely named after, the thumb-ring of an archer. Indeed, Vesalius included a drawing of such a ring when describing the cricoid in his Fabrica

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A Roman signet ring

Posterior view of the cricoid cartilage

Drawing of a Turkish archer's thumb ring
Andreas Vesalius' De Humani Corporis Fabrica, 1543

An ancient Roman archer's thumb ring


Clitoris is derived from the Greek word for clitoris, kleitoris, which in turn comes from kleio (to close, as with a door or latch), perhaps in reference to those portions of the labia minora that enclose the clitoris, or to the clitoris as a metaphorical gateway to the vagina.

Some have suggested that clitoris may be derived from the Greek verb for tickle, kleitorizein (the German word for clitoris is der Kitzler, the tickler). However,
kleitorizein may be dervied from Kitzler (kleitorizein also means "to touch the clitoris").

Gabriele Falloppio (of Fallopian tube fame) was the first to systematically describe the external anatomy of the clitoris back in the 16th century.

The clitoris is rarely represented in its entirely in textbook diagrams and anatomical models. The average length of the adult clitoris from the visible glans to the embedded ends of the crura (which attach to the bones of the pelvic girdle) is about 4".

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The clitoris surrounding the penis during intercourse.
The outer layers of the woman's skin and fat are not shown and the
penis is represented
as a feature-less cross-section. The ascending
portion of the clitoral shaft can be seen above the glans (the glans is the
portion usually visible). The shaft bends posteriorly at its apex
and divides into the two "legs" (crura ) which encircle the vaginal opening
and the penis.
Drawing by Robert Latou Dickinson, in Human Sex Anatomy, 1949.

Lateral view of the clitoris
This diagram is from a US college website, but I lost the link.
If anyone knows, please leave a comment.