Final answer:
Double circulation is a type of circulatory system found in amphibians, reptiles, birds, and mammals. It involves the circulation of blood in two separate circuits: the pulmonary circuit and the systemic circuit. This system provides efficient delivery of oxygen and nutrients, as well as precise control of blood flow to different organs and tissues.
Step-by-step explanation:
Double Circulation in Animals
Double circulation is a type of circulatory system found in amphibians, reptiles, birds, and mammals. It involves the circulation of blood in two separate circuits: the pulmonary circuit and the systemic circuit. In the pulmonary circuit, blood is pumped from the heart to the lungs to pick up oxygen and remove carbon dioxide. In the systemic circuit, the oxygenated blood is then pumped to the rest of the body to deliver oxygen and nutrients and remove waste products.
Advantages of Double Circulation
Double circulation provides several advantages for organisms. Firstly, it ensures efficient delivery of oxygen and nutrients to the body's tissues. The separation of oxygen-rich blood from oxygen-poor blood prevents mixing and allows for a higher concentration of oxygen in the systemic circuit. This is important for animals with high energy demands, such as birds and mammals.
Secondly, double circulation enables precise control of blood flow to different organs and tissues. By selectively constricting or dilating blood vessels, organisms can redirect blood flow to areas that need it the most. For example, during exercise, the body can increase blood flow to the muscles and decrease blood flow to the digestive system.
Examples of Double Circulation
Two examples of animals that have double circulation are humans and birds. In humans, deoxygenated blood from the body enters the right atrium, is then pumped into the right ventricle, and finally sent to the lungs for oxygenation. Oxygenated blood from the lungs returns to the left atrium, is pumped into the left ventricle, and then distributed to the rest of the body. In birds, the process is similar, with the right ventricle pumping blood to the lungs, and the left ventricle pumping oxygenated blood to the body.