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
History of beliefs about the human body the senses to identify what has gone wrong. The Ebers Papyrus refers to many god-like and spiritual infestations of the body that could not be explained at the time. Despite the explanations for maladies by spiritual rational, the interventions described to investigate and see the body were distinctly disconnected for the spirit or life force of the body and was principally about what could be seen or touched. Descriptions of the exact placement of the heart within the body, the circulation of blood are in no doubt accurate as Egyptians practiced embalming their dead by removal of organs and placement