Trachea Diffusion of oxygen and carbon dioxide takes place across the walls of the smallest tubes, called tracheoles, which penetrate tissues and even indent individual cells. Gas may be conducted through the respiratory system by means of active ventilation or passive diffusion. Unlike vertebrates, insects do not generally carry oxygen in their haemolymph. This is one of the factors that may limit their size. A tracheal tube may contain ridge-like circumferential rings of taenidia in various geometries such as loops or helices. Taenidia provide strength and flexibility to the trachea. In the head, thorax, or abdomen, tracheae may also be connected
Traditional Chinese medicines derived from the human body parts of the human body should be used as drugs, such as bone, flesh, and gall. This is really very rude and inhuman. In the present category, all parts of the human body that have been used as drugs are recorded. The use of drugs from the human body that is not contrary to morality is recorded in detail. Those drugs that are cruel or foul [慘忍邪穢] are not recorded in detail. But all of them are listed in this category. (tr. Luo 2003: 4133) Li does not give prescriptions for 12 of the 35 human drugs, which he considered