arteriole (n.)

late 14c., "an arterial blood vessel," 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, and 14c.-16c. artery in English also could mean "trachea, windpipe." Medieval writers, based on Galen, generally took them as a separate blood system for the "vital spirits." The word is used in reference to artery-like systems of major rivers from 1805; of railways from 1844.

Proto-Indo-European root meaning "to raise, lift, hold suspended." 

It forms all or part of: aerate; aeration; aerial; aero-; aerobics; aerophyte; aerosol; air (n.1) "invisible gases that surround the earth;" airy; aorta; anaerobic; aria; arterial; arterio-; arteriosclerosis; arteriole; artery; aura; malaria; meteor. 

It is the hypothetical source of/evidence for its existence is provided by: Greek aerein "to lift, raise up;" Lithuanian svarus "heavy," sverti "to lift, weigh;" Old English swar, Old Norse svarr, Old High German swar, German schwer "heavy."