Circulatory system is the first organ system to become functional ... Heart has completely separated: 2 atria, 2 ventricles, 4 chambers, and adult bird has complete double circulation: low-pressure ...

It has four chambers. Humans have a double circulatory system, which means the blood passes through the heart twice on each loop around the body. It travels from the heart to the lungs ...

The aorta, a large blood vessel responsible for transporting oxygenated blood from the heart to the rest of the body, plays a ...