(or pharyngeal tonsils), mass of lymphatic tissue attached to back wall of nasal pharynx (upper part of throat opening into nasal cavity proper); surface of adenoids consists of microscopic hairlike projections (cilia) covered with film of mucus, in which infectious airborne agents and dust particles are trapped; cilia move constantly in wavelike motions to propel mucus down to pharynx; adenoids contain glands that secrete mucus; antibodies, which arrest and absorb infectious agents, also thought to be at least partially formed within adenoids; adenoids may enlarge or become infected during childhood and sometimes cause swelling and inflammation; surgical removal of adenoids is common in such cases.