From the archives:

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.


From the archives:

Biceps comes from the Latin words bis (twice) and caput (head). The biceps brachii is a muscle with two "heads" (or origins).

"Biceps" is typically used in both the singular and plural, though to be strictly proper the correct plural form is "bicipites". About a quarter of the usage on the Internet is the incorrect, pseudo-singular "bicep".

The biceps brachii was named in 1734 by the German anatomist Bernhard Weiss (who went by the Latinized name of Albinus).

Albinus (1697-1770)


From the archives:

Coronary, from the Latin corona, garland, wreath, or crown. Corona is also Latin for boundary.

When viewed from above, it can be seen that the right and left coronary arteries (more specifically, the right coronary and circumflex branch of the the left coronary) encircle the heart like a crown.

The coronal suture of the skull, linking the frontal bone to the parietals, is arranged vertically instead of encircling the cranium. It is very roughly reminiscent of the style favored by Roman emperors for the wearing of a garland, or corona , i.e., high on the forehead, and this has been suggested as the inspiration of suture's name.

However, the another Latin meaning of corona is a boundary such as the edge of a field and, perhaps from this definition, the anterior edge of the hair on the head. Especially in one with a receding hairline, the position of the coronal suture and the pattern of hair growth closely match, and perhaps from this relationship came the name of the suture Others suggest the term simply is in reference to the edge of the frontal bone.

In any event, corona in an anatomical sense does not appear in any extant Roman writings. It first makes its appearance around the 10th century in Latin translations of Arabic anatomical texts.

A coronal section initially referred to a cut made along the coronal suture. The term has since become generalized to mean any such cut that separates anterior and posterior regions.

Some non-anatomic words derived from the Latin corona include coronation and coroner (the original definition of the latter word was "an officer appointed by the crown").

A transverse section through a plane containing the heart valves. The circumflex artery curves around the mitral valve on the left, and on the opposite side, the right coronary artery curves around the tricuspid, with both vessels almost touching posteriorly and thus completing the crown.
Julius Caesar wearing a corona.
Courtesy of the
Library of Congress


From the archive:

Amygdala, Greek for almond. A mass of gray matter located within the temporal lobe of the cerebrum; It has the shape and approximate size of an almond kernel.


Among other activities, the amygdala functions in the processing of fear-related memories and helps to coordinate appropriate responses to fearful situations. In other words, using the amygdala, we learn to be afraid.

In humans, tumors in or near the amygdala have been associated with uncontrolled rage. Consider the tragic case of Charles Whitman, who, on an August day in 1966, stabbed to death his wife and mother and then climbed to the observation deck of the University of Texas Tower with a high-power rifle. For 90 minutes he gunned down people below, killing 14 and wounding 19 before being shot and killed by police. In a note found later he wrote about his "unusual and irrational thoughts” and wanted his body to be examined to see if a physical cause could be found for his "mental anguish". An autopsy was performed and a tumor compressing his amygdala was found. No proof of cause and effect but compelling evidence nonetheless of the role the amygdala plays in behavior.

Charles Whitman

McLeod, M. (2000). Charles Whitman: The Texas Tower Sniper. Crimelibrary.com/serial/whitman/index.htm


From the archives:

, from the Latin tragos, goat: the skin-covered, cartilaginous flap just anterior to the opening of the external ear canal. "Covering your ears" with your fingers is done by pressing the tragus down over the opening.

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Photo by Tony Boon
The strange etymology seems to be related to the tufts of hair that will often appear on the tragus, particularly in older men, though just how this hair is linked to goats is a matter of conjecture. The most common explanation is that an imaginative ancient Greek anatomist, name unknown, was reminded of the hair on the chin of a goat (the one problem with this idea: the hair on the tragus really doesn't look much like mental goat hair). Or, perhaps, its the stiff, bristly texture typical of the hair that's so caprine. Or, as it's been suggested, in particularly luxuriant cases these hairs might remind one of the animal-like (i.e. hairy) ears of the satyr, the half-man, half-goat of Greek mythology. None of the explanations are compelling, but they're all we got.

Another name for the tragus-hair is barbula, the diminutive of barbus, Latin for beard and the ancestral root of barber, barb, and beard.

Goat or satyr? Barbula on the tragus of a middle-aged man.
Photo by C. Carpenter

A satyr from an ancient Roman woodcut: hardly the image of the sexy satyr usually depicted, but the hairy ear is nice (yes, that is an ear and not the side-hair of a baldpate). Adapted from the Dictionary of Greek and Roman Antiquities, 3rd Edition by Anthony Rich. 1874


From the archives:

Cauda equina
comes from the Latin cauda (tail) and equina (horse). The "horse's tail" is an appropriately named collection of dorsal and ventral spinal nerve roots that hang off the spinal cord.

The the term was coined in 1600 by the French anatomist Andrea Laurens (also known by his latinized name, Andreas Laurentius).

Andrea Laurens's original drawing of the cauda equina, with this accompanying description (translated from the Latin):
"Spinal cord displayed after immersion in water with all of the nerves exiting in a hair-like configuration suggesting a horse's tail..."

The rabbinical writers of the Talmud in the second century A.D. were the first to describe the structure. The Talmud was not an anatomy text of course, but accurate anatomical descriptions were required so that rabbis, when examining sacrificed animals, could determine whether the meat was either kosher or trefe, i.e. unsuitable, according to Jewish law.

Interestingly, the ancient rabbis were more accurate in their accounts than the two greatest anatomists of the enlightenment, Andreas Vesalius (the first "modern" anatomist) and Thomas Willis (the father of neuroanatomy). Both failed to recognize the cauda equina's existence, over a dozen centuries after the Talmudic accounts, even while providing detailed drawings of the spinal cord and its nerves. Vesalius was active a couple of generations before Andrea Laurens. Willis, from England, worked a couple of generations after Laurens, apparently unaware of the Frenchman's accomplishments.

Other anatomical structures with cauda in their names include the caudate lobe of the liver (meaning "towards the tail " or in this context, inferior) and the caudate nucleus of the cerebrum, a mass of gray matter with a long tail.

The coda, or the "tail end" of a musical composition, is also derived from cauda.


From the archives:

Adventitia comes from the Latin word adventicius, foreign, which in turn is derived from adventus, arrival (formed by ad, to, and venire, to come). The term is used to describe specific layers, typically the outermost layers of certain hollow organs, that develop from nearby tissues.

An example is the tunica adventitia which ostensibly is part of the structure of arteries and veins, forming their outer coats, but in fact is derived from surrounding connective tissue. By the same token, the outer adventitia layer of some alimentary canal organs are also formed from the local connective tissue, in particular those organs, such as the esophagus and rectum, that are not within the peritoneal cavity and thus not in need of a protective serous coating.


Diagram adapted from Wikipedia

Another anatomical use, again in the sense of something "foreign", is seen in the adventitious bursae which form in locations where bursae are usually not found, typically in response to trauma or friction. An example is the bursa that may develop over the ischial tuberosisty in people who sit for extended periods of time. Inflammation of this bursa was called "weaver's bottom" back in the day.

A non-anatomical but related word is advent: coming or arrival.


From the archives:

Adam’s apple: The anterior lump in the neck, formed by the laryngeal prominence of the thyroid cartilage, the largest cartilage of the larynx.

The Adam’s apple is usually larger in men, but the overall size of the thyroid cartilage, relative to body size, is the same in both men and women. What is often different is the angle that the two anterior, vertical plates (laminae) of the cartilage make in forming the prominence: in a typical man the angle is about 90 degrees; in most women, a shallower 120. Thus in men, the cartilage usually protrudes a bit more.

It is not uncommon for a woman to have an Adam's apple larger than a man.


Regarding the etymology of "Adam's apple", typical is the entry in Webster's 1913 dictionary stating the term "… is so called from a notion that it was caused by the forbidden fruit, (an apple) sticking in the throat of [Adam]." This is pure supposition, and in fact, the term Adam's apple arose through a very early mistranlation of the Hebrew for “male bump”, tappuach ha adam, that was used to denote this anatomical feature. This is understandable as adam is Hebrew for “man” and tappuach is very similar if not identical to an old Hebrew word for apple (although some modern scholars now translate tappuach as quince or citron and others consider the term a generic for any spherical citrus). There is no mention in Genesis that the "forbidden fruit" was actually an apple anyway.


From the archive:

Muscle comes from the Latin for "little mouse", musculus (the diminutive of mus).

Two explanations are usually given for the peculiar transformation of mouse to muscle. One has it that the movement of a contracting muscle under the skin is reminiscent of a mouse moving beneath a rug; The biceps brachii is typically used as an example. The other explanation is that, in the abstract at least, some muscles look a bit like mice: specifically those with long, thin tendons (the mouse tails) emerging from oblong muscle bodies. The muscles of the forearm are among many that are illustrative.

The second explanation is as plausible as the first, Although neither seem compelling. But why any relatively large muscle would be called a little mouse in the first place remains a mystery. (A sense of humor on the part of early anatomists cannot be ruled out!). In any event, it could easily have been muscles of dissected animals and not humans that were were the inspiration for the name.

Interestingly, mussel (the mollusk) is also derived from musculus, perhaps because some species have the shape of a mouse ear.

The difference in spelling between "muscle" and "mussel" is due to the different post-Latin paths taken by musculus. Muscle comes to us through French; mussel came out of Old English.

The little mice of the anterior forearm: some imagination may be required. From Henry Gray's Anatomy of the Human Body, 20th ed. (1918) via Bartleby.com

A couple of musse
ls doing their best to impersonate mouse ears. From www.town.barnstable.ma.us


From the archives:

Cubital, from the Latin cubitus, elbow; also: the distance from the elbow to the fingertips (a "cubit"), an ancient unit of measurement used by the Egyptians, Greeks and Romans, among others. Depending on the time and place, it ranged between 18 and 25 inches, give or take.

Cubitus comes from cubo, Latin for "I lie down", supposedly because the ancient Romans were in the habit of resting on the forearm during meals.

Illustration by Gilbert Ford


From the archives:

Iris, directly from the Greek iris, rainbow. Aristotle also used the term to describe the bright halos that sometimes encircle the moon.

Rainbows and halos: no wonder the Danish anatomist Jacob Winslow, in 1721, chose to call the pigmented, circular arrangement of smooth muscle that surrounds the pupil the iris. Though it was with this coinage that the term become firmly established in anatomy, the Greek author and physician Rufus of Ephesus also called this part of the eye the iris a full 1,600 years earlier, apparently unbeknownst to Winslow (Ephesus also named the optic chiasm).

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A lunar iris, per Aristotle

Iris was a Greek goddess before being a rainbow: she was a messenger among the Greek pantheon. Iris became associated with rainbows because they were a symbol of good news in Greek society and she apparently brought her fair share of welcome reports.

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The Goddess Iris.
Detail from ancient Greek clay vase. Photo from Sotheby's London F15923. © Sotheby's


From the archives:

Hyoid, from the Greek letter Υ (upsilon) and eidus, Greek for shape; thus, "shaped like an upsilon".

The derivation of the word is better understood if you think of hyoid as "Υoid", The "Υ", however, is not a reference to the shape of the upper case upsilon (Υ) but rather to the lower case form of upsilon (υ).

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Upslion, lower and upper cases

Its exclusive anatomical use is for the υ-shaped hyoid bone in the neck and related structures such as the sternohyoid and stylohyoid muscles. It is one of the oldest words in anatomy, first used by the seminal Greek anatomist Herophilus around 300 B.C.
The hyoid bone

If hyoid means Υ-oid, where did the initial "h" come from? In the spoken language of the ancient Greeks, whenever upsilon was used as the first letter in a word, it was always preceded by "rough breathing", i.e., the "h" sound, and was so indicated in Greek writing by a small mark in front of the letter (i.e. 'Υ). Scholars of Greek later replaced the mark with the letter "h". This pattern is seen in many other Greek-derived words, such as those that begin with hyper- and hypo-.

The hyoid is the only bone in the body that does not articulate directly with other bones. It is a favorite of murder-mystery writers because it is evidence of strangulation when broken.