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
The Human Body (TV series) The Human Body (TV series) The Human Body is a seven-part documentary series, first shown on 20 May 1998 on BBC One and presented by medical scientist Robert Winston. A co-production between the BBC and The Learning Channel, the series looks at the mechanics and emotions of the human body from birth to death. The series was nominated for numerous awards, winning several, including three BAFTA awards, four RTS awards and a Peabody Award. Described as the BBC's "first major TV series on human biology", it took over two years to make and aimed to be the definitive set of