Trachea annular ligaments of trachea. The epiglottis closes the opening to the larynx during swallowing. The trachea develops in the second month of development. It is lined with an epithelium that has goblet cells which produce protective mucins (see "Respiratory epithelium"). An inflammatory condition, also involving the larynx and bronchi, called croup can result in a barking cough. A tracheotomy is often performed for ventilation in surgical operations where needed. Intubation is also carried out for the same reason by the inserting of a tube into the trachea. From 2008, operations have experimentally transplanted a windpipe grown by stem cells, and
Traditional Chinese medicines derived from the human body "Three Corpses; demonic spirits believed to live in the human body and hasten death" and "gǔdú" 蠱毒 "gu poisoning"; a poison produced by venomous insects; cast a black magic spirit possession over someone". The first "Bencao gangmu" prescription for human nails is not from Chinese medical texts but from Daoist rituals for expelling what (Cooper & Sivin (1973: 220) describe as the "Three Corpse-Worms 三尸, the chief of the "inner gods" who are to the individual microcosm what the celestial bureaucracy is to the cosmos." Prescription 52.6.1, the 斬三尸法 "Method of Beheading the Three Corpses", involves supernaturally cutting the nails