Insect Exchange Flashcards
Exoskeleton
less permeable
chiton (waxy)
waterproof
where do insects live?
On land
Why is this bad?
they can become easily dehydrated through water loss
Adapted gas exchage surface?
for gas exchange and water loss
Hairs
trap moist air outside the insect
Spiracles
open and close
Cuticle
thick
waxy
waterproof
SA:V ratio?
relatively small SA:V ration
Segmented Body
each segment has spiracles
Gas movement in Spiracles?
gases move randomly in and out of spiracles by diffusion
Trachea
big tube
Tracheoles
small tube
Insects gas exchange pathway
spiracles trachea strengthening rings tracheoles muscle
large SA:V ratio
increases rate of exchange
small but waterproof
spiracles increase surface exposed to environment
many small branching tracheoles
Short diffusion path
tracheoles in direct contact with respiring tissues
length of trachea/tracheoles limited by diffusion speed
Movement of environmental medium
maintain concentration gradient
ventilation movements
muscles contrations refresh air within tracheoles
Movement of internal medium
not applicable for gas exchange in insects
Minimising water loss
waterproof covering spiracles closing hair
