insects Flashcards
what does flying require
a lot of energy
a lot of oxygen
what are insects normally
terrestrial (live on the earth not water)
what do all terrestrial organisms have as a feature
water evaporates from the body surface
what does efficient gas exchange require
a thin, permeable surface with a large surface area
what has insects developed to reduce water loss
rigid waterproof exoskeleton which is covered by a cuticle
surface area to volume ratio of insects
small
where does gas exchange happen in insects
holes called spiracles running across the side of the body
what do the spiracles lead to
system of branched, chitin lined air-tubules called trachea
what can spriacles do
open and close like valves to allow gas exchange but reduce water loss
what do resting insects rely on
diffusion to take in oxygen and remove c02
what happens during flight
movement of abdomen ventilate the trachea
what are the end of trachea called
tracheoles
where does gas exchange happen
at the end of the tracheaols
oxygen passes directly to the cells - very rapid
what happens to fluid levels in tracheoles during flight
decreases to provide more surface area for gas exchange
what happens when abdomen expanded
thorax spiracles open
what happens when abdomen is compressed
thorax spiracles close
why are maxium diameter never over 20 um
need short pathway for diffusion
diffusion rapid enough to supply sufficient energy to cells and tissues
change in fluid level in trachealos during flight
decrease during flight which produces more surface area for gas exchange
shortens diffusion pathway even more
relationship between thoracic spindle and those in abdomen
when thoracic spindle opens one in abdomen close
when spindle close, abdomen open
change in shape of abdomen effects spindles
abdomen expands thorax spindles open, abdomen close
abdomen compressed, thorax spindles close, abdomen opens
