Amphibians

• Young amphibians (eg tadpoles) use gills to breathe as they live in water
• When amphibians grow, their gills disappear and they grow lungs
• Some amphibians retain gills for life
• Adult amphibian lungs lack/ have a reduced diaphragm
• Amphibians diffuse gases through their skin, to aid this their skin is moist
• Amphibian skin has vascular tissues to make gaseous exchange possible
• Label:

  A) Inspiration

  B) Expiration

  C) Buccal cavity expands

  
• Inspiration: allows air to flow into the lungs
• Expiration: gases leave the lungs
• Buccal cavity expands: increases volume of buccal cavity so that air can enter it
• The buccal pump mechanism is used by some frogs (e.g. tree frogs)
• The buccal cavity can be expanded by opening the mouth wide or inflating the cheeks with air.