What is the X in X-mas?
late 14c., from Anglo-French arterie, Old French artaire (13c.; Modern French artère), and directly from Latin arteria, from Greek arteria "windpipe," also "an artery," as distinct from a vein; related to aeirein "to raise" (see aorta).
They were regarded by the ancients as air ducts because the arteries do not contain blood after death; medieval writers took them for the channels of the "vital spirits," and 16c. senses of artery in English include "trachea, windpipe." The word is used in reference to artery-like systems of major rivers from 1805; of railways from 1850.
artery ar·ter·y (är'tə-rē)
Any of a branching system of muscular, elastic blood vessels that, except for the pulmonary and umbilical arteries, carry aerated blood away from the heart to the cells, tissues, and organs of the body.