Amphibians, reptiles + birds

• What are the three groups of animals discussed in the study material?

  Amphibians, reptiles, and birds
• What are the characteristics of the respiratory surface in amphibians, reptiles, and birds?

  • Large surface area for gas diffusion
  • Moist surface for rapid gas diffusion
  • Short diffusion pathway (thin walls)
  • Blood pigments (e.g., haemoglobin) for oxygen transport
  • Internal lungs to minimize water and heat loss (not for amphibians)
  • Ventilation mechanism for gas exchange
• Why do amphibians use their moist skin for gas exchange when inactive?

  Because it allows for gas exchange in water
• What type of lungs do active amphibians use?

  Simple lungs
• How do frog lungs compare to human lungs?

  Frog lungs have a relatively small surface area
• What do tadpoles use for gas exchange?

  Gills
• What are the characteristics of reptilian lungs compared to amphibian lungs?

  • Reptilian lungs are more efficient
  • Gaseous exchange occurs exclusively in lungs
  • Reptilian lungs are sac-like with complex folding
  • Reptiles have ribs but no diaphragm
• How do reptiles ventilate their lungs?

  By moving their ribs with intercostal muscles
• What adaptations do birds have for efficient gas exchange?

  • Warm-blooded with high respiration rate
  • Small, compact lungs with branching bronchi
  • Parabronchi with extensive blood capillary network
  • Large, thin-walled air sacs for ventilation
• How do bird lungs facilitate gas exchange during flight?

  Wing muscle action ventilates the lungs
• What role do parabronchi play in bird respiration?

  They are sites for gaseous exchange
• What are the differences in gas exchange mechanisms among amphibians, reptiles, and birds?

  • Amphibians: moist skin and simple lungs
  • Reptiles: efficient lungs, no skin exchange
  • Birds: complex lungs with parabronchi and air sacs