Trachea into left and right main bronchi. The trachea begins level with the sixth cervical vertebra and the carina is found at the level of the fifth thoracic vertebra (T5), opposite the sternal angle and can be positioned up to two vertebrae lower or higher, depending on breathing. The trachea is surrounded by rings of hyaline cartilage; these rings are incomplete and C-shaped. The cricoid cartilage is attached to the first tracheal ring at top of the trachea and acts as the bottom of the larynx. There are fifteen to twenty rings in total, separated by narrow intervals. These reinforce the
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