[ii] Gas Bladder + Lungs

• Elongated gas filled sacs

  Gas bladders
• Air for the swim bladder comes from:

  1. Digestive tract
  2. Directly from blood
• Swim bladders are used for buoyancy

  Lungs are used for respiration
• Swim bladders vs Lungs

  • Swim bladders are NOT paired, lungs are paired
  • Swim bladders have single circulation, lungs have double circulation
• Air filled sacs found in air breathing vertebrates

  Lungs
• Movement of air into trachea is regulated by the glottis
• Trachea → Bronchi → Bronchioles → Alveoli
• Lung modifications:

  1. Unequal sizes
  2. Rabbit lungs have a larger right lung compared to the left
  3. Only one lung
  4. Lungfishes