Blood returns from the lungs to the left side of the heart to be pumped to the rest of the body. There's substantial back pressure in the lungs, so if it went straight from there to the rest of the body without going back to the heart for a boost, it would be more of an ooze than a flow.
This problem could be overcome by starting with a higher blood pressure going to the lungs in the first place, but this introduces additional problems, namely that the barrier between the capillaries in the lungs and the airspace in the alveoli is fairly thin to maximize gas transfer, and increasing the pressure substantially here would mean either making the barrier thicker (and thus impeding gas transfer) or risking "blowouts".
If you're asking why the left side... it has to go somewhere, and the right side is already just about in the middle of the body where the great veins run, so it's just more efficient (not that that's necessarily a consideration in evolution) to have venous blood return to the right side, and oxygenated blood return to the left. There are people in which this gets mixed up (the condition is called "transposition of the great vessels", and there are various kinds, some of which are immediately life-threatening at birth... for example, there's a kind where venous blood returning to the heart is just pumped straight back out to the body, while the other side of the heart just pumps blood around and around through the lungs. Before birth, this isn't such a big deal, since the lungs aren't actually doing anything and the ductus arteriosus allows blood from both sides of the heart to mix anyway, but this normally closes shortly after birth).
What's very interesting about the heart and lungs is that the pulmonary ARTERIES carry DE-oxygenated blood (arteries usually carry oxygenated blood). As blood comes back to the heart,the oxygen rich blood is carried to the heart via the pulmonary VEINS. Three to five (varies in each person) pulmonary veins pump oxygenated blood into the left atrium of the heart.
because on the left the oxygen comes in and out and on the left the heart pumps blood.
the left side of the heart gets its blood from the lungs through the pulmonary veins. this blood is deoxygenated. hope this helped...
The right side is deoxygenated blood; the left side is oxygenated blood (returned from the lungs).
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.
Blood. The right side pumps deoxygenated blood and the left pumps the oxygenated blood.
The SEPTUM separates the right side of the heart from the left side. This is to prevent the mixing of oxygenated blood with deoxygenated blood.
The left side of the heart contains oxygen-rich blood. The right side of the heart contains deoxygenated blood.
The right side pumps deoxygenated blood and the left side pumps oxygenated blood.
The answer to this very question is simply gas. When blood leaves the heart deoxygenated it immediately goes to the lungs to receive oxygen which is a gas and this gas goes to the left side of the heart.
Because the right side of your heart pumps deoxygenated blood and the left side pumps oxygenated blood.
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.
No, the deoxygenated blood enters and leaves the heart through the right side and the oxygenated blood enters and leaves the heart through the left side. Both sides of the heart are separated by a wall called a septum. The wall between the left and right atria is the interatrial septum and the wall between the left and right ventricles is the interventricular septum.