Gas Exchange in insects Flashcards
1
Q
How are insects adapted to prevent water vapour loss?
A
- Spiracles can open/ close by valves, preventing loss of water vapour.
- Have tough exoskeleton (impermeable) –> prevents water vapour loss.
- Hairs around the spiracles
2
Q
What type of insects are we specifically talking about in terms of gas exchange?
A
- Terrestrial insects
3
Q
Instead of lungs, what do insects have to for exchange of gases?
A
- Have tracheal system, instead.
4
Q
What is the name of the holes in insects that allows O2 to diffuse into insect and CO2 to exit insect? Where are they found?
A
- Spiracles.
- Spiracles are found on thorax and abdomen.
5
Q
What path does air take after it enters the spiracles in insects?
A
- Enters tracheae –> tracheole –> diffuses into muscle cells
6
Q
What are the adaptations of the insect gas exchange system that allows for efficient diffusion?
A
- Tracheoles: thin walls SO short diffusion distance.
- Tracholes: highly-branched SO larger surface area for diffusion.
- Muscle contraction of thorax/ abdomen: maintains steep concentration gradient for diffusion.
7
Q
What do large insects have in their tracheal system that small insects don’t?
A
- Air sacs that can be compressed and expand through movement of thorax/ abdomen.
8
Q
What is found at the end of tracheoles in insects? What is the issue with this? How is this problem solved?
A
- Tracheole fluid.
- Issue: with this fluid, gases will be unable to diffuse into muscle cells.
- The tracheole fluid is removed.
9
Q
How is the tracheole fluid removed in insects?
A
- Muscle contraction
- Not enough O2 (once you reach certain level of muscle contraction.)
- Anaerobic respiration in muscle cells.
- Lactic acid/ solutes build up in muscle cells; lowering water potential in muscle cells.
- Water component of tracheole fluid (higher water potential) moves into muscle cells (lower water potential.)
