Carina of trachea Carina of trachea In anatomy, the carina is a ridge of cartilage in the trachea that occurs between the division of the two main bronchi. This occurs at the lower end of the trachea (usually at the level of the 4th thoracic vertebra, which is in line with the sternal angle, but may raise or descend up to two vertebrae higher or lower with breathing). This ridge lies to the left of the midline, and runs antero-posteriorly (front to back). Foreign bodies that fall down the trachea are more likely to enter the right bronchus. The mucous membrane of the
Traditional Chinese medicines derived from the human body centuries after Li Shizhen considered the bioethical and biomedical dilemmas of using human drugs, 20th-century technological and medical advances have raised new related questions of organ transplants, transplantation medicine, organ trade, tissue banks, human cloning, and the commodification of human body parts (Awaya 1999, Nie 2002, Scheper-Hughes and Wacquant 2002). Traditional Chinese medicines derived from the human body Li Shizhen's (1597) "Bencao gangmu", the classic materia medica of traditional Chinese medicine (TCM), included 35 human drugs, including organs, bodily fluids, and excreta. Crude drugs derived from the human body were commonplace in the early history of medicine. Some of these