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
Theology of the Body nature of human beings in relation to God. The "Theology of the Body" presents an interpretation of the fundamental significance of the body, and in particular of sexual differentiation and complementarity, one which aims to challenge common contemporary philosophical views. Nevertheless, the pope's personalistic phenomenology is "echoing what he learned from St. John of the Cross" and is "in harmony with St. Thomas Aquinas". Francis Bacon was an early empiricist who focused on problems of knowledge. In his Great Instauration, he argued that the current state of knowledge is immature and not advancing. His purpose was for the human mind