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
What Is This? following week. The group decided to change their name to the Red Hot Chili Peppers, played several more shows at various L.A. clubs and musical venues, and eventually recorded a demo tape, all while Slovak and Irons were still playing with What Is This?. A few months later, What Is This received a record deal with MCA Records and the Red Hot Chili Peppers received a joint deal with EMI America and Enigma Records. Hillel Slovak and Jack Irons decided to leave the Red Hot Chili Peppers and stay with What Is This? as the latter was their primary musical