Insect Tracheal System

Gas exchange insects:

Insects __________ by moving whole body.

This moved air into a network of tubes called __________.

These branch to make __________ to reach evert cell directly. The gases are not carried in a __________ __________

ventilate

trachea

tracheoles

blood stream

Tracheal system of an insect

Tracheoles end inside muscle fibres

Thoracic spiracles open __________ as abdomen expands (Inspiration)

abdomen

Abdomen spiracles open __________ as the abdomen compresses (Expiration )

later

Insects ventilate through __________

spiracles

Air enters the spiracle allowing _________ to travel along among a network of tubes called __________ to reach the cells in the insect’s body

oxygen

tracheae

Terrestrial Adaptations

Air tubes branching through body

Gas exchanged by diffusion across moist cells lining terminal ends not through open circulatory system

Trachea kept open by circular bands of _______.

chitin

Branch to form ___________ that reach every cell

tracheoles

Ends of tracheoles are _______-

moist

Oxygen delivered directly to _________ cells. Insect blood does not carry ___________.

respiring

oxygen

How do the adaptations enhance efficiency?

Oxygen delivered directly to respiring cells

• can pump body to move air around in tracheal systems

But size of animal limited by slow _________ rate

diffusion