Both! Blood enters the atria (upper chambers) on both sides of the heart at the same time. Blood from the body, carrying carbon dioxide, enters the right atrium. Blood from the lungs, carrying oxygen, enters the left atrium. The two atria contract together, pumping the blood into the two ventricles (lower chambers). The ventricles then contract, pumping blood out of the heart. Blood from the right ventricle goes to the lungs, where it loses its carbon dioxide and picks up oxygen. It then goes to the left atrium. Blood from the left ventricle goes to the body, where it delivers oxygen and picks up carbon dioxide. See: http://www.bbc.co.uk/science/humanbody/body/factfiles/heart/heart.shtml
deoxygenated blood
The right side of the heart takes the blood returning from the body and sends it to the lungs. It is high in carbon dioxide and low in oxygen. After the blood goes to the lungs it returns tot he left side of the heart to be pumped back out tot he body and it low in carbon dioxide and high in oxygen.
The heart is divided into four chambers. I personally find it helpful, however, to think of the heart as being divided into two sides, instead, a left and right side. The right side of the heart is larger and more powerful than the right.
Systemic circulation is the flow of blood from the left side of the heart, through the tissues of the body excepting pulmonary tissues, and emptying into the right atrium of the heart. Pulmonary circulation is the flow of blood from the right side of the heart through the lungs to become freshly oxygenated and empties into the left atrium.
The five main parts are the arteries, capillaries, veins, heart and most people don't count blood but blood is also one!
Body
The right.
to the rest of the body to supply blood for daily activities
The right side of the heart pumps blood to the lungs, and the left side pumps blood to the rest of the body. The blood on the right side is deoxygenated and the blood on the left side is oxygenated.
To the left side of your heart.
the right side of the heart contains deoxygenated blood.
The left side of the heart supplies blood to the body through the aorta, the largest artery in the body. The right side of the heart sends blood to the lungs for oxygenation.
The left side of the heart pumps oxygenated blood out to the body.
The right side of the heart receives blood from the body. The left side receives blood from the lungs.
The left side of the heart contains oxygen-rich blood. The right side of the heart contains deoxygenated blood.
The left side of the heart pumps oxygenated blood throughout the body.
Blood in the left side of the heart is redder because it is carrying oxygen.