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 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