Amphibians live on both land and water, and so, their respiratory system must allow them to take in oxygen not only from the air, but also from water. Thus, they have a very complex respiratory system.
When amphibians stay in the water, they breathe through their skin, but once they come on land, they breathe with their lungs, and through the membranes in their mouth. Even when the lungs are used, amphibians obtain oxygen through their skin- and for this to be possible, the skin must remain moist at all times.
When an amphibian is in the larval stage, it uses gills for breathing. These gills later develop into lungs as the amphibian undergoes the changes that make it an adult. Some salamanders have neither gills nor lungs, but breathe through their mouths and skins.
To sum up, amphibians can get oxygen into their bodies in three different ways. The first way is by using lungs, which are similar to ours. The second way is through their skin, and the last way, is by using gills. Did you know that amphibians don’t breathe constantly like humans do? Instead, they just breathe now and then, when their body needs more oxygen.