Final answer:
Double circulation is a type of circulation that occurs in mammals and birds, where blood passes through the heart twice during each complete circuit of the body.
Step-by-step explanation:
Double circulation refers to the type of circulation that occurs in mammals and birds, where blood passes through the heart twice during each complete circuit of the body. This is in contrast to single circulation, which occurs in fish, where blood passes through the heart only once during each circuit. In double circulation, the heart is divided into two chambers: the atria receive blood returning to the heart, and the ventricles pump blood away from the heart.
An example of double circulation is the human circulatory system. The right atrium receives deoxygenated blood from the body, which is then pumped into the right ventricle. The right ventricle pumps the deoxygenated blood to the lungs to get oxygenated. The oxygenated blood is then returned to the left atrium and pumped into the left ventricle. The left ventricle pumps the oxygenated blood out to the rest of the body.
In summary, double circulation is a type of circulation that occurs in mammals and birds, where blood passes through the heart twice during each complete circuit of the body. The heart is divided into two chambers - atria and ventricles - to receive and pump blood, respectively. An example of double circulation is the human circulatory system.
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