Biology: Gas Exchange: Insects Flashcards
Outline the structure of an insects gas exchange system
-air filled pipes, tracheae -tracheae divide to tracheoles -tracheoles penetrate individual cells
-spiracles are pores on exoskeleton where air enters trachea -tracheae supported by strengthened rings to prevent collapse
Explain how air moves in and out of the insect tracheal system
-cells respiring, oxygen concentration falls at tracheole ends -concentration gradient for oxygen diffusion is established -high carbon dioxide concentration in respiring cells
-carbon dioxide concentration established out of cells
How does ventilation work in insects?
-muscles contract between each body segment -pumping raises pressure -air forced out of spiracles down pressure gradient -insect compresses tracheae for pumping mechanism
What adaptations do tracheoles have?
-thin walls -highly branched -fluid in ends of trachea
What is the importance of thin walls in tracheoles?
short diffusion distance
What is the importance of being highly branched for tracheoles?
increases surface area
Why is fluid in the ends of trachea an important adaptation?
-reduces volume, more air drawn in -air to liquid is more efficient exchange -tracheal fluid withdrawn into body fluid to increase surface area exposed to air
How does water move into cells from tracheoles?
-anaerobic respiration produces lactate -lactate soluble and lowers water potential
-water moves in via osmosis
Why are muscles important in an insects gas exchange system?
creates pumping mechanism which allows for a concentration gradient to be maintained
Why are spiracles opening and closing a beneficial trait?
prevents water loss
