Question

Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?

Answer 1

Hint: The mammals and birds are the warm-blooded animals. They need to maintain their temperature no matter what the environment is. Oxygenated blood is rich in oxygen while deoxygenated blood is rich in carbon dioxide.

Complete step by step answer: As we know that warm-blooded animals like mammals and birds body temperature remain constant. The warm-blooded animals maintain their body temperature constant. When they can cool or warm their body when they are in a hotter or cooler environment respectively. To maintain their body temperature constant they need a huge amount of energy. Therefore they need more oxygen for cellular respiration to produce more energy. In mammals, the circulatory system is much more efficient and separates the oxygenated blood from deoxygenated blood. Due to this feature, they get more amounts of oxygen, energy and ability to maintain their body temperature constant.

Additional Information: The animals belonging to reptiles, amphibians and osteichthyes (fishes) are cold-blooded animals. As a fish has a two-chambered heart (one atrium and one ventricle). In this, the heart pumps out the deoxygenated blood which is oxygenated via gills. This oxygenated blood is transported to the other body part from where deoxygenated blood is returned back to the heart. This type of circulation is called single circulation. In the case of reptiles and amphibians, they have a three-chambered heart (two atria and one ventricle). Here, the right atrium receives the oxygenated blood from other parts whereas the left atrium receives from skin/lungs/gills. Although it gets mixed in a single ventricle which pumps out the mixed blood. This is called incomplete circulation.

Note: In mammals, they have a double circulatory system i.e. two separate circulatory pathways for oxygenated blood and deoxygenated blood. Humans and other mammals have a four-chambered heart. It has two atriums and two ventricles. The oxygenated blood and deoxygenated blood received by the left and right atria respectively and passes the blood to the same side of the ventricles. The ventricles pump out the blood without mixing them up.