Gas exchange in vertebrate groups

Created by

mayesha

Cards (7)

what are the major problems for terrestrial organisms?
water evaporates from body surfaces - could result in dehydration
they are likely to lose a lot of water - this is because gas exchange surfaces must be thin and permeable with a large surface area but water molecules are very small and pass through gas exchange surfaces, so gas exchange surfaces are always moist
what have animals done to overcome the conflict of needing to conserve water with the risk of water loss at the gas exchange surface?
they have evolved different methods to overcome this
what are some adaptions that have been evolved to prevent the loss of water at the gas exchange surface?
gills can’t function out of water but on land, the tracheae of insects and the lungs of vertebrates do
lungs are internal, minimising the loss of water and heat
they allow gas exchange with air and allow animals to be very active
how are amphibians adapted for efficient gas exchange?
e.g. frogs, toads and newts
their skin is moist and permeable with a well-developed capillary network just below the surface
gas exchange takes place through the skin and, when the animal is active, in the lungs also
how are reptiles adapted for efficient gas exchange?
e.g. crocodiles, lizards and snakes
their lungs have a more complex internal structure than those of amphibians, increasing the surface area for gas exchange
how are birds adapted for efficient gas exchange?
the lungs of birds process large volumes of oxygen because flight requires a lot of energy
birds don’t have a diaphragm but their ribs and flight muscles ventilate their lungs more efficiently than the methods used by other vertebrates
for efficient gas exchange, what do the more advance multicellular organisms need?
a ventilation mechanism
an internal transport system, the circulation system, to move gases between the respiratory surface and respiring cells
a respiratory pigment in the blood to increase its oxygen-carrying capacity