Download mechanisms assist it with gas exchange

Under each heading explain how/why each animal’s adaptations/ mechanisms assist it with gas exchange.
INSECTS
Internal tubule system
 Protects the gas exchange system
 Can be sealed in wet or dry
environments
 Has air sacs as a reserve of air when
spiracles are sealed
 Supported by rings of chitin to keep
structures supported
FISH
Internal membrane system
 Gills continuously bathed in water
keeping filaments separated and
allow gas exchange to be most
efficient
 Water supports the gas exchange
system, if exposed to air, the
structures can collapse and stick
together
 Provides large surface area needed
for diffusion to be most efficient
MAMMALS
Internal tubule system
 Protects the gas exchange system
 Keeps lungs moist preventing from
drying out
 Allows a wide range of habitats e.g.
land and water
 Provides large surface area for
diffusion to be most efficient
Haemolymph
 Bathes cells and the ends of
tracheoles and moves freely in open
circulatory system
 Dissolves gases for diffusion
Blood and blood vessels
 Blood distributes oxygen around
body cells (via haemoglobin) and
collects carbon dioxide from cells to
return to the gills
 Blood is contained within a closed
circulatory system
 Diffusion occurs in very thin walled
blood vessels (capillaries)
Blood and blood vessels
 Blood distributes oxygen around
body cells (via haemoglobin) and
collects carbon dioxide from cells to
return to the lungs
 Blood is contained within a closed
circulatory system
 Diffusion occurs in very thin walled
blood vessels (capillaries)
Breathe air with 21% oxygen
High concentration of oxygen, diffusion
occurs down concentration gradient
Ventilate water with 3% dissolved
oxygen
Uses counter-current exchange where the
blood and water move towards each other.
Breathe air with 21% oxygen
High concentration of oxygen, diffusion
occurs down concentration gradient
Ventilate the GE system by
Body movement (segments) moves air
inside trachea
Air sacs for storage of air
Spiracles can be sealed in some insects
Ventilate the GE system by
Need to be in water at all times so gills are
supported and filaments separated
Use of buccal cavity to increase pressure to
volume of water moving over gills.
Ventilate the GE system by
Lungs allow storage of air so mammals are
able to live in a variety of habitats
Breathing – mechanical motion of inflating
and deflating lungs through use of the
diaphragm, intercostal muscles and ribs.
Land dwelling
Can live in a variety of habitats due to
diffusion of air into tracheal system.
Spiracles can be sealed to exclude moisture
loss in dry environments.
Aquatic dwelling
Utilise fully the small percentage of
dissolved oxygen in water due to counter
current flow
Land and aquatic dwelling
Lungs allow a huge variety of habitats
Small mammals in damp or dry habitats
Whales, dolphins etc in aquatic
environment
Energy requirements are low
Energy requirements are moderate
Energy requirements are high
Diffusion occurs without energy needed,
although some muscle movement needed
for moving air throughout GE system
Ventilation requires continual movement of
the mouth buccal cavity.
closed transport system (heart)
Breathing requires a lot of energy
Closed transport system (heart)
No temperature maintenance.
Cold blooded (less energy needed)
Warm blooded animals also require a lot of
energy to maintain this temperature.
Small sized
Moderate size
Variety of sizes
Due to diffusion of gases, limitation of size
– air needs to make into the depths of the
insect. Size related to energy requirements
and limitation of efficiency of diffusion.
Relatively low energy animal so oxygen
demand is only moderate. Closed
circulation system with respiratory pigment
molecules aids transport of oxygen to cells
and blood aids removal of CO2.
Energy demand varies greatly according to
animal. Size varies greatly (dependent on
energy requirements). Lung system size is
in relation to energy requirements and size
of animal.