Origins
The word 'artery' entered English in the late fourteenth century from Latin 'artēria,' which was borrowed directly from Greek 'artēría' (ἀρτηρία). In Greek, the word originally meant 'windpipe' — the trachea — and was only later extended to refer to the large blood vessels leading from the heart. This semantic history reflects one of the most consequential errors in the history of medicine: the ancient Greek belief that arteries carried air rather than blood.
The etymology of the Greek word itself is debated. The most common theory connects it to 'aírein' (ἀείρειν, to raise, to lift), suggesting that the windpipe was understood as the tube that 'raises' or draws air into the body. Another theory links it to 'aḗr' (ἀήρ, air), making 'artēría' literally 'the air-vessel.' A third, less accepted theory connects it to the verb 'ararískein' (to fit together), suggesting it was named for the rings of cartilage that 'fit together' to form the trachea.
The medical confusion arose from a simple observational error. When ancient anatomists dissected cadavers, the arteries were consistently empty — after death, blood drains from the arterial system into the venous system and the tissues. The veins, by contrast, remained full of dark blood. From this observation, the logical conclusion seemed clear: veins carry blood, arteries carry air. The physician Praxagoras of Cos (4th century BCE) explicitly taught this doctrine, and it influenced medical thinking for centuries.
Development
The error was first corrected by Galen of Pergamon (129–c. 216 CE), who demonstrated through animal vivisection that arteries in living bodies carry blood — bright red blood, visibly different from the dark blood in veins. Galen showed that if you tied off an artery and cut it open, blood would be found inside. This was a revolutionary finding, though Galen's broader circulatory theory remained flawed (he believed blood was constantly produced by the liver and consumed by the body). The full understanding of blood circulation was not achieved until William Harvey's 'De Motu Cordis' (On the Motion of the Heart) in 1628.
Despite the correction of the ancient error, the name 'artery' persisted — a permanent etymological fossil of the air-vessel theory. In modern anatomy, arteries are defined as blood vessels that carry blood away from the heart. Most arteries carry oxygenated blood (bright red), but the pulmonary arteries carry deoxygenated blood from the heart to the lungs — making them arteries by structure and function, despite carrying 'venous' blood.
The figurative use of 'artery' to mean a main route of transportation dates from the early nineteenth century. A 'major artery' or 'arterial road' carries traffic away from the city center, just as an artery carries blood away from the heart. This metaphor is so embedded in urban planning vocabulary that some cities have designated 'arterial roads' as an official category in their road classification systems.
Greek Origins
The medical vocabulary built on 'artery' is extensive: 'arterial' (adjective), 'arteriosclerosis' (hardening of the arteries, from Greek 'sklḗrōsis,' hardening), 'atherosclerosis' (a specific type involving fatty deposits, from 'athḗra,' porridge), 'arteriography' (imaging of arteries), 'arteriotomy' (surgical incision into an artery), and 'endarterectomy' (surgical removal of plaque from inside an artery). The related word 'aorta' — the body's largest artery — comes from Greek 'aortḗ,' from 'aírein' (to raise), making 'aorta' and 'artery' probable etymological siblings.