Gas exchange in Vertebrate

Problems for terrestrial organisms with gas exchange
1. Water evaporates from their bodies = get dehydrated
  1. Solutions!
    1. Surfaces need to be thin
    2. Permable
    3. Large surface areas
The Lung
1. Birds and mammals are active. How have they adapted for gas exchange
  1. With air, it is a less dense medium
2. Have internal lungs to reduce water loss
AMPHIBIANS
1. Gas exchange takes place through the skin and lungs
  1. What does the skin act as
    1. the surface of gas exchange with either water or air
  2. Features of the skin
    1. Moist
    2. Permable
    3. Well developed capillary network just below the surface
  3. Features of the lungs
    1. simple elastic sacs
    2. Have a good blood supply
    3. Have no diaphragm or rib cage
    4. Lungs are inflated by forcing air into them by movements of the floor of the mouth
Reptiles
1. Examples of reptiles
  1. Crocodile
  2. Lizard
  3. Snakes
2. Features of reptiles
  1. Move on all four limbs without their bellies toughing the ground
  2. The ribs
    1. Have pairs of ribs that project from the backbone
    2. Ribs provide. ....
      1. Support
      2. Protection to organs in the body cavity
    3. Are involved in the ventilation of the lungs
      1. The lung is complex and internal. More complex that the amphibians lung
        Has an ingrowth of tissues
        this increases the surface area for gas exchange
Birds
1. Birds use the lungs as their site for gas exchange
  1. Large volumes of oxygen are needed to provide energy for flight
  2. Ventilation of the lungs in birds in a lot more efficient as they have a system of air sacs
    1. These air sacs function as bellows
  3. The lungs ventilate by the movement of the ribs
    1. During flight
      1. flight muscles ventilate the lungs

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Gas exchange in Vertebrate

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	Created by hayley over 11 years ago