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
Body in the cylinder that it had been part of a ventilation shaft. On 13 July 1945 three small boys were playing with the cylinder. They were rolling it through the streets when one tried to see what was inside. At first they saw what appeared to be a shoe, however, on closer inspection it appeared to be part of an human skeleton. The police were called to the scene and they used an Oxy acetylene burner to cut the cylinder open. The contents were revealed to be a complete human skeleton accompanied by a number of items. The police removed the remains and