Insects

• what do insects use for gas exchange?

  Microscopic air-filled pipes called TRACHEAE
• what give the insect a large surface area?

  TRACHEAE and tracheoles
• What does air move into the tracheae through?

  through pores on the surface called spiracles
• what does oxygen travel down?

  the concentration gradient towards the cells
• what do the tracheae branch off into?

  smaller tracheoles which have thin, permeable walls and go to individual cells

  THIS MEANS THAT oxygen diffuses directly into the respiring cells - the insect's circulatory system does not transport O2
• What does the insects circulatory system NOT transport?

  oxygen
• what happens to carbon dioxide from the cells?

  it moves down its own concentration gradient towards the spiracles to be released into the atmosphere
• what movements do insects user to move air in and out of the spiracles?

  rhythmic abdominal movements