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
History of beliefs about the human body much on discourse about bodies, rather than on material bodies themselves. Drawing on Mikhail Bakhtin's 1965 "Rabelais and His World", they promoted a more materially orientated direction in the history of the body. The Ebers Papyrus is an Egyptian medical text and is the oldest known record of the human body, dating back to 3000 BC. The Ebers Papyrus describes the body by physical examination and what can be felt. Clinical investigations such as the Pulse, percussion of the body, the recognition of diseased or disordered states. “If thou examinst a swelling of the covering of his belly’s horns above