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
101 Things Removed from the Human Body 101 Things Removed from the Human Body 101 Things Removed from the Human Body and 101 More Things Removed from the Human Body is a British "shockumentary" series directed by Eric Schotz, which is narrated by Mitch Lewis. The program features tales of foreign objects that have been removed from human bodies in the form of a countdown from 101 to 1. Items included are javelins, a boat anchor, a bicycle pump, a bag of nails, an ice pick, and a human body. The documentary series was first broadcast on Sky One in October 2003. When the show was re-broadcast