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
Explorers of the Human Body new educational program, introducing the audience to the human body. Shin Dong-yup was chosen to be the lead MC, with the Super Junior members being regulars and co-MCs of the program. Ratings for the show became the highest of all three shows that aired in SBS's new "Good Sunday" lineup as the show is educational and entertaining to watch. It was also the first and currently the only variety show that included every member of Super Junior as regulars. Each episode has a main topic to explore regarding the human body. In the first episode, which involved the tongue and