It is an air gap that allows air to escape rather than building up in the pipe and creating an air hammer within the pipes (banging noise), and problems with drainage. (think about pouring out of a can that doesnt have the second hole punched in it.
Suction Therapy : Suction therapy is provided to assist in the removal of bronchial secretions that cannot be expectorated by the patient spontaneously. Suct...
aversion therapy (aversive therapy) a form of behavior therapy that uses aversive conditioning, pairing undesirable behavior or symptoms with unpleasant stimulation in order to reduce or eliminate the behavior of symptoms. The term is sometimes used synonymously with aversive conditioning.