Gas Exchange- Insects

Active
1. Movements of abdomen ventilate the tracheae
2. Ends of tracheoles fluid-filled and close to muscle fibres
3. Interface where gas exchange takes place
4. Oxygen dissoles in fluid and diffues directly in muscle cells
5. No respiratory pigment or blood circulation need
6. CO2 diffuses reverse
Resting
1. Diffusion through spiracles, tracheae and tracheoles
2. Same method for O2 and CO2
Problems
1. Live in arid so water evaporates from body risking dehydration
2. Gas exchange need thin permeable surface conflicts with water conservation
  1. Insects therefore have waterproof layer (e.g. exoskeleton with thin waxy layer over thick layer of chitin and protein
Structure
1. Paired holes:spiracles
  1. Branches chitin lined tubes:tracheae
    1. Smalles tubes: tracheoles
  2. Can open and close: reduces water loss
  3. Hairs on spiracles: reduces water loss and prevents solid particles entering

Resource summary

	Created by Fauzia Ali over 8 years ago