Insects Flashcards
What do insects have instead of lungs
A tracheal system
Does the blood of an insect carry o2
No
Name all 3 parts of the tracheal system in the correct order
- spiracles
- trachea
- tracheoles
Describe the spiracles
They are a series of pores that run long the abdomen of the insect the allow O2 and CO2 to enter and leave. Trachea attach to the spiracles
Describe trachea
They are a network of internal tubes. They have a ring of chitin within them which provide strength and keeps the tubes open
Describe tracheoles
Trachea branch into tracheoles. Tracheoles are very fine tubes which extend throughout the tissues in the insects to deliver O2 to all respiring cells
What 3 ways does gas move through the tracheal system
- diffusion
- mass transport
- anerobic respiration
How does gas move through the tracheal system through diffusion
Respiratoy gases move down the concentration gradient
How does efficient diffusion occur in an insect
Diffusion distance must be short so therefor insects are limited to a certain size
How does mass transport move gases
They contract muscles which increase air movement in the trachae. The muscle contraction pump de oxygenated air out of the spiracles which causes a pressure gradient so now oxygenated air can enter the trachea down the pressure gradient
How does anaerobic respiration move gases in the trachea system
O2 transport can be facilitated by the production of lactate during intense activity
What happens during intense activity
- anaerobic respiration
- this increase lactate
- wp decreases in muscles
- water enters muscles via osmosis
- Air drawn into tracheoles
- increase sa for gas exchange
- O2 and CO2 diffuses faster through gases than liquids
- increases respiration
Where does anerobic respiration occur
Tracheoles
Hoe does lacate lower wp
Its soluble and therefor lowers water potential
Why is good that water enter muscles from tracheoles
Means there is less water in the tracheoles so increase SA for gas exchange therefor O2 is supplied for rapidly for respiration
How do spiracles limit water loss
- acts like valves that can open and close
- have setae which are hair which trap a layer moist air to reduce water potential gradient as water potential is more negative and lower in the atmosphere that the insect
What ways do insects limit water loss
- small sa:v
- waterproof exoskeleton
- spircales
How SA made big
- many branching tracheoles
- removal of water during excerise increase SA
Why cant insects sue their bodies as a exchange surface
The have water proof chitin exoskeleton and a small SA:V ration to limit water loss
Explain the process of gas exchange in insects
- gases move in and out of tracheae through spiracles
- a diffusion gradient allows o2 to diffuse into the body tissue while waste co2 diffuses out
- contraction of muscles in the trachea allows mass movement of air in and out
How are insects adapted fro gas exchange
- tracheoles have thin walls so shot diffusion distance to cells
- highly branched tracheoles so large SA
- tracheae provide tubes full of air so fast diffusion into the insect
