Trachea act as a resonator to amplify sound. In some birds, the tracheal rings are complete, and may even be ossified. In amphibians, the trachea is normally extremely short, and leads directly into the lungs, without clear primary bronchi. A longer trachea is, however, found in some long-necked salamanders, and in caecilians. While there are irregular cartilagenous nodules on the amphibian trachea, these do not form the rings found in amniotes. The only vertebrates to have lungs, but no trachea, are the lungfish and the "Polypterus", in which the lungs arise directly from the pharynx. The word "trachea" is used to
Explorers of the Human Body Explorers of the Human Body Explorers of the Human Body (Hangul: 인체탐험대; Hanja: 人體探險隊) was one of the three shows of the newly revamped "Good Sunday", a lineup of variety shows that airs every Sunday evening at 5:30 pm KST on SBS. The show's aim was to answer curious questions about the human body, where the Super Junior members perform the answers by doing experiments with their own bodies. The show succeeded in attracting a wide audience due to its comedic and educational content. After previous popular shows "X-Man" and "Reverse Drama" ended, SBS's "Good Sunday" decided to air a