body, organic structure, physical structure - the entire physical structure of an organism (especially an animal or human being); "he felt as if his whole body were on fire"

system - a group of physiologically or anatomically related organs or parts; "the body has a system of organs for digestion"

respiratory tract - the passages through which air enters and leaves the body

respiratory organ - any organ involved in the process of respiration

trachea - one of the tubules forming the respiratory system of most insects and many arachnids