Human body Human body The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body. It comprises a head, neck, trunk (which includes the thorax and abdomen), arms and hands, legs and feet. The study of the human body involves anatomy, physiology, histology and embryology. The body varies anatomically in known ways. Physiology focuses on the systems and organs of the human body and their functions. Many systems and mechanisms interact in order to maintain homeostasis,
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