Insect Gas Exchange

Question 1

Why do insects need tracheal system?

Answer 1

high oxygen requirement
hard exoskeleton reduces gas exchange

Question 2

control

Answer 2

sphincters allow spiracles to open and close
kept closed to reduce water loss
kept open when co2 builds up or needs more oxygen

Question 2

How does gas exchange take place in insects?

Answer 2

• Air enters spirales in thorax and abdomen
• air enters tracheae and then tracheoles where oxygen diffuses in moisture of walls and into surrounding cells

Question 3

adapations

Answer 3

tracheae lined with chitin (impermeable rings) to keep open when bent or pressed
tracheoles small to spread throughout tissues

Question 4

What role does lactic acid have?

Answer 4

oxygen dissolves into it
co2 produced released via spiracles

Question 5

what happens when water builds up at bottom tracheoles?

Answer 5

it slows down diffusion
lactic acid builds up in cells to decrease water potential so water moves back into cells

Question 6

what is mechanical ventilation of tracheal system?

Answer 6

air is pumped into system by muscular pumping of thorax and abdomen
it changed volume therefore pressure so air is drawn in or forced out

Question 7

What are collapsible air sacs for?

Answer 7

act as air reservoir to increase volume air moved through system
inflated/deflated by movements of thorax and abdomen

Question 8

what does tracheal fluid do?

Answer 8

when it is drawn into surrounding cells it increases the surface area for gas exchange