Describe the structure of the bird’s heart

In birds, for the first time in the process of evolution, a four-chambered heart appears, consisting of two atria and two ventricles. The chambers on the left side of the heart contain oxygenated blood, while the chambers on the right side contain carbonated blood. There is only one aortic arch (right) and departs from the left ventricle. Blood moves quickly through the vessels, gas exchange in the tissues occurs quickly, and a lot of heat is released. Because of this, birds maintain a constant body temperature.