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
Facebook real-name policy controversy the acronym is employed, Facebook automatically changes to lower-case all letters except the first. (Use of periods, e.g. D.L.G., will result in a message telling users that "Profile names can't have too many periods.") Therefore, someone commonly known in real life by a name such as Mary De Leon Guerrero Mafnas would have to resort to using what on Facebook would end up being "Mary Dlg Mafnas". The message is not accompanied by an option to challenge/appeal the restriction or to send Facebook documentation that the format is how one normally formats their name in real life. In January 2015,