Trachea into left and right main bronchi. The trachea begins level with the sixth cervical vertebra and the carina is found at the level of the fifth thoracic vertebra (T5), opposite the sternal angle and can be positioned up to two vertebrae lower or higher, depending on breathing. The trachea is surrounded by rings of hyaline cartilage; these rings are incomplete and C-shaped. The cricoid cartilage is attached to the first tracheal ring at top of the trachea and acts as the bottom of the larynx. There are fifteen to twenty rings in total, separated by narrow intervals. These reinforce the
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