PATHOLOGY

Detailed explanation-1: -The heart consists of four chambers in which blood flows. Blood enters the right atrium and passes through the right ventricle. The right ventricle pumps the blood to the lungs where it becomes oxygenated. The oxygenated blood is brought back to the heart by the pulmonary veins which enter the left atrium.

Detailed explanation-2: -A typical heart has two upper and two lower chambers. The upper chambers, the right and left atria, receive incoming blood. The lower chambers, the more muscular right and left ventricles, pump blood out of the heart.

Detailed explanation-3: -Different types of hearts have different numbers of these chambers: two-chambered hearts have one ventricle and one atrium. three-chambered hearts have one ventricle and two atria. four-chambered hearts have two ventricles and two atria.

Detailed explanation-4: -Human beings belong to class Mammalia, they are warm blooded animals and their heart has four chambers two atrium and two ventricles, double circulation of blood takes place. Whereas fishes have two-chambered heart, amphibians and reptiles have three chambered heart.