Trachea to prevent swallowed matter from entering the trachea. In the fourth week of development of the human embryo as the respiratory bud grows, the trachea separates from the foregut through the formation of tracheoesophageal ridges which fuse to form the tracheoesophageal septum and this separates the future trachea from the oesophagus and divides the foregut tube into the laryngotracheal tube. Before the end of the fifth week, the trachea begins to develop from the laryngotracheal tube which develops from the laryngotracheal groove. The first part of the cephalic region of the tube forms the larynx, and the next part forms
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