Trachea Diffusion of oxygen and carbon dioxide takes place across the walls of the smallest tubes, called tracheoles, which penetrate tissues and even indent individual cells. Gas may be conducted through the respiratory system by means of active ventilation or passive diffusion. Unlike vertebrates, insects do not generally carry oxygen in their haemolymph. This is one of the factors that may limit their size. A tracheal tube may contain ridge-like circumferential rings of taenidia in various geometries such as loops or helices. Taenidia provide strength and flexibility to the trachea. In the head, thorax, or abdomen, tracheae may also be connected
Name Is 4Minute Name Is 4Minute Name Is 4Minute is the fourth mini-album by South Korean girl group 4minute, released on April 26, 2013. It features the lead single "What's Your Name?", which became the group's most successful single after peaking at number one on the Gaon Singles Chart and being one of the best selling singles of the year. On February 4, 2013, Cube Entertainment announced that 4Minute would release new material in the first half of the year. It was further explained that their new music would more closely resemble their debut sound, more "groovy and powerful" according to their record