Gas Exchange In Insects

Question 1

Why is the tracheal system used?

Answer 1

Insects have a waxy exoskeleton which helps with protection + water retention which doesn’t allow for effective gas exchange so the tracheal system evolved

Question 2

How does the tracheal system work?

Answer 2

Mostly through tracheal fluid at the ends of tracheoles

Question 3

What happens when the insect is at rest?

Answer 3

The tracheal fluid seeps into the tracheoles from surrounding cells

Question 4

What happens when the insect is active and why?

Answer 4

The muscles draw up the tracheal fluid which provides them with oxygen containing fluid for respiration and lowers the pressure in tracheoles which draws in more air through the spiracles increasing the surface area available for oxygen to diffuse through tracheal walls directly

Question 5

How are air sacs used for ventilation in insects?

Answer 5

Air sacs can be squeezed by flight muscles to push air in and out

Question 6

How are flight muscles used in ventilation in insects?

Answer 6

Flight muscles can alter the volume of the thorax to ventilate the tracheal systems

Question 7

What is the specialised breathing mechanism for ventilation in insects?

Answer 7

As insects expand their abdomen they close spiracles at the back end of the body - when they contract their abdomen they open up the spiracles at the rear and close the ones at the front