Trachea are generally highly elastic but they may calcify with age. The trachealis muscle connects the ends of the incomplete rings and contracts during coughing, reducing the size of the lumen of the trachea to increase the rate of air flow. The esophagus lies posteriorly to the trachea, adjoining along the tracheoesophageal stripe. Circular horizontal bands of fibrous tissue called the annular ligaments of trachea join the tracheal rings together. The cartilaginous rings are incomplete to allow the trachea to collapse slightly so that food can pass down the esophagus. A flap-like epiglottis closes the opening to the larynx during swallowing
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