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 Yang Qi energy where as a female has dominant Yin energy. Transgenderism, hermaphroditism and other variations of the body can be explained by the Yin and Yang Qi ideas of the body much better than the European counterparts. Other types of change in the world were classified by Wood, Fire, Earth, Metal and Water. Applied to the body these 5 forces were the Liver, Heart, Spleen, Lung, and Kidney. These representations of the physical world in the body was understood dynamically and represents a deeper connection to the non animate objects and surroundings of a human. The body was not