Tracheae refer to the primary respiratory tubes that carry air from the external environment into the lungs of an organism. The word itself has no synonym as it is a specific term. However, in other animals, the tracheae can be referred to as spiracles, bronchi, or bronchioles. Insects possess a complex network of tracheae that deliver oxygen to their bodies, and they are also known as tracheoles or air sacs. In some cases, the term windpipe can be used to describe the tracheae in larger animals. Nonetheless, while there are various terms used for the tracheae in different animals, they all serve the essential function of delivering air to facilitate respiration.