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 body has in the world. All cultural ideals of the body in the early modern period deal with deficiencies and disorders within a body, commonly told through a male ideal. Ideas of the body in the early modern period form the history of how bodies should be and how to correct the body when something has gone wrong. Therefore, early modern conceptions of the body were not biological as there was not a restrictive biological view of the human body as established by modern science. Conceptions of the body are primarily either eastern, based in China and involving practices such