AZYGOS, in anatomy, a vein otherwise called vena sine pari, because single. See VEIN. The vena azygos is the third branch of the ascending trunk of the cava.—It descends through the right side of the cavity of the thorax, and at its arrival at the eighth or ninth vertebra, begins to keep the middle, and sends forth on each side, intercostal branches to the interstices of the eight lower ribs; and there is divided into two branches, the larger of which is inserted sometimes into the cava, but oftener into the emulgent: The other enters the cava, commonly a little below the emulgent, but is seldom joined to the emulgent itself. See CAVA and EMULGENT.
