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 these views, that the soul has aspects that can't be felt by normal methods, and physical manifestations that can be felt. "For even if one and being are spoken of in several ways, what is properly so spoken of is the actuality" -Aristotle in DeAnima Aristotle forms the idea of Hylomorphism, that the soul and the body are not capable of being split apart without destroying both in the process. Despite this idea of the body and the soul Aristotle viewed disorder in what could be seen and felt. He was a proponent of the humoral theory that classified disorder