Adaptations in insects

• Tracheoles have thin walls

  • Shortens diffusion distance of gases to cells
• Tracheoles are highly branched:

  • Increases surface area for gas exchange
• Fluid in the ends of trachea where it joins tissues

  • Gas exchange from air to liquid occurs in the tracheole which allows gases to diffuse to tissues faster
  • Tracheal fluid can be withdrawn into the body fluid to increase the surface area of the tracheole exposed to air
• Muscles can pump body and force air in/out

  • Maintains concentration gradient for gases
• Spiracles can be closed/ not open all the time

  • This prevents water loss - keeps organism waterproof