Gas exchange in insects

Question 1

Starting from the spiracles, list the structures found in an insect’s gas exchange system…

Answer 1

Spiracles
Trachea
Tracheole
Tracheal fluid at the ends of the branches of tracheoles

Question 2

What do the spiracles allow?

Answer 2

for air to flow in and out of the spiracles. (You should avoid saying things like ‘gases’)

Question 3

To prevent the trachea and tracheoles from collapsing, what are the tubes supported by?

Answer 3

Chitin

Question 4

What is the main site of gas exchange in insects?

Answer 4

trachea or tracheae

Question 5

What is the fluid at the end of each tracheole called?

Answer 5

tracheal fluid

Question 6

compare the trachea in a human vs insect

Answer 6

.a human trachea has much bigger diameter and length than an insect trachea

.humans only have one trachea, whereas insects have many tracheae

Question 7

An insect’s tissues are respiring.

This means that the oxygen concentration in the insect tissues is…

Answer 7

lower than the oxygen concentration in the air

Question 8

The oxygen concentration in the insect tissues is lower than the oxygen concentration in the air.

As a result, when air flows into the insect and down the tracheoles, there is an…

Answer 8

oxygen concentration gradient from the air in the tracheoles to the respiring muscles.

Question 9

as cells respire, there’s a higher CO2 concentration in the muscle cells than the tracheal fluid, so…

Answer 9

CO2 diffuses out of the muscle tissues into the tracheal fluid. From there, CO2 diffuses into the air in the trachea. This air the flows out of the insect through spiracles