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
The Body (1970 film) The Body (1970 film) The Body is a 1970 UK scientific documentary film directed and produced by Roy Battersby. In the film, external and internal cameras are used to showcase the human body. The film's narrators, Frank Finlay and Vanessa Redgrave, provide commentary that combines the knowledge of human biologists and anatomical experts. The film's soundtrack, "Music from the Body", was composed by Ron Geesin and Roger Waters, and includes songs that were made using the human body as a medium. Waters is also the narrator of one scene. In August 1971 Nat Cohen, whose company distributed the film, said