Theheartof an amphibian, such as afrog, hasthree chambers, one ventricle and two atria. Blood from the ventricle travels to the lungs and skin where it is oxygenated and also to the body. ... Warm blooded animals such asbirds and mammalshave a high metabolic rate and anefficientcirculation of blood is a necessity.

The four-chambered heart has a distinct advantage over simpler structures: It allows us to send our "dirty" blood to the cleaners-the lungs-and our "clean" blood to the rest of the body without having to mix the two. That system is veryefficient.

Three chamber of frog is not as efficient than four chamber heat bird because in frog intermixing of pure and impure blood take. place while in bird four chamber are there so the impure blood which come from superior vena cava and inferior vena cava passes through right auricle and then right ventricle and then blood pass through lung where. oxygen is added and it comes to left auricle and Left ventricle as bird as 4, chamber so intermixing of blood does not take place