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
101 Things Removed from the Human Body from their body survived. This program also aired in the USA on the Discovery network's "The Learning Channel" in October 2007. The program contains stories, including a man having a uterus and a man with a teratoma, a type of large tumor. The large jaw tumor segment featured the work Mercy Ships, who have operated floating hospital ships in impoverished areas around the world. 101 Things Removed from the Human Body 101 Things Removed from the Human Body and 101 More Things Removed from the Human Body is a British "shockumentary" series directed by Eric Schotz, which is narrated by