Flow of blood through human heart Oxygen rich blood from the lungs comes to the thin -walled upper chamber of the heart on the left, the left atrium.
The left atrium relaxes when it is collecting this blood is transferred to it. When the musculer left ventricle contracts reaches, the blood is pumped out to the body.
De - oxygenated blood from the body to the upper chamber on the right , the right atrium, and it expands . As the right atrium contracts , the corresponding lower chamber , the right ventricle , dilates , This transfer blood to the right ventricle , which in turn pumps it to the lungs for oxygenation.
Since ventricles have to blood into various organs, they have thicker muscular walls than the atria do.
The whole process is repeated continuously . The blood circulatory system in human is an example of double circulation since the blood travels twice through the heart in one complete cycle.
(i) The pathway of blood from heart to the lungs and back to the heart is called pulmonary circulation.
(ii) The pathway of blood from heart to rest of the body back to the heart is called systemic circulation . Theses two together make double circulatory system.
