Trachea the trachea. The trachea is no more than 4mm diameter during the first year of life, expanding to its adult diameter by late childhood. The trachea is more mobile and of more variable length, deeper, and smaller in children. The trachea is lined with a layer of pseudostratified ciliated columnar epithelium. The epithelium contains goblet cells, which are glandular, modified simple columnar epithelial cells that produce mucins, the main component of mucus. Mucus helps to moisten and protect the airways. Mucus lines the ciliated cells of the trachea to trap inhaled foreign particles that the cilia then waft upward toward
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