Right side * Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium. * As the atrium contracts, blood flows from your right atrium into your right ventricle through the open tricuspid valve. * When the ventricle is full, the tricuspid valve shuts. This prevents blood from flowing backward into the atria while the ventricle contracts. * As the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated. Left side * The pulmonary vein empties oxygen-rich blood from the lungs into the left atrium. * As the atrium contracts, blood flows from your left atrium into your left ventricle through the open mitral valve. * When the ventricle is full, the mitral valve shuts. This prevents blood from flowing backward into the atrium while the ventricle contracts. * As the ventricle contracts, blood leaves the heart through the aortic valve, into the aorta and to the body.
It goes through the pulmonary artery (the only artery with deoxygenated blood as far as I know) to the lungs to be oxygenated. It then returns to the heart through the pulmonary vein (only vein with oxygenated blood as far as I know) and into the left atrium. Then to the left ventricle then to the rest of the body's organ's cells through the aorta.
Blood from the right ventricle goes to the lungs for gas exchange in the pulmonary circulatory system while blood from the left ventricle goes around the whole body in the systemic circulatory system.
The pulmonary trunk leads to the pulmonary arteries, which take the still-deoxgenated blood from the heart to the lungs. Once the red blood cells pick up oxygen there, the pulmonary veins bring the oxygenated blood back to the left side of the heart to be pumped to the body.
Once blood passes through the pulmonary semi-lunar valve, it goes to the pulmonary artery which leads to the lungs.
Somewhere else in the body!
Lungs
That is partly true, but thinking of atrial function only in this way is misleading. The right atrium has a job that is subtle and very important. The atria do not have valves at the 'intake' end, so there is not a push in the same way that ventricles push blood. When the right atrium is in systole, or contracting, the contraction is not strong; if it were it would cause back flow to the veins feeding the right heart. While the atrium contracts, the relaxing right ventricle is taking in blood from the atrium. But at the same time, blood is still flowing directly from the veins right into the right ventricle! Then when the ventricle is contracting and sending blood to the lungs, blood flow can continue unimpeded into the relaxing atrium. So the atrium's job is really to prevent inertia of blood during the beating cycle; it helps the blood to keep moving without coming to a jolting stop during each beat.
All mammals (monotremes, marsupials, and placental mammals) have the same heart structure: a four chambered heart. The four chambers are the left atrium, the left ventricle, the right atrium, and the right ventricle. The right atrium receives deoxygenated blood from the veins. It pumps it into the right ventricle. The right ventricle pumps it into the pulmonary arteries, which go to the lungs. The lungs have received oxygen and give it to the blood coming through. The now oxygenated blood flows back to the heart by pulmonary veins, and is received by the left atrium. The left atrium pumps the oxygenated blood into the left ventricle. The left ventricle pumps the blood to all of the body through arteries.
The blood then flows into to the right ventricle, and out into the pulmonary artery through the pulmonic valve.
When we inhale, the blood in the capillaries in our lungs will get the oxygen (the blood will be oxygenated) and it will go to the heart, first in the left atrium,mitral valve,left ventricle and to the aortic valve that will transport it to the different parts of body. Then, when the blood is deoxygenated, it will go to the inferior vena cava, right atrium,tricuspid valve,right ventricle, and pulmonary veins and the deoxygenated blood will go to the capillaries in our lungs and transport the carbon dioxide to the alveoli and we exhale it.
If the tendinous cord, also known as the chordae tendineae, is not present and the right ventricle contracts, the blood would flow backwards into the right atrium instead of being pumped out into the pulmonary artery. This condition is known as tricuspid regurgitation or tricuspid insufficiency.
right ventricle
Right ventricle
In normal human adult physiology, the CO2 concentration in the right atrium is relatively high (typically 46mmHg). In contrast, after exchange in the lungs, blood entering the left atrium has a CO2 concentration of roughly 40 mmHg. This will be different in some heart conditions and fetal circulation.
Blood stream
Right atrium
right atrium -> right ventricle -> pulmonary artery -> pulmonary vein -> left atrium -> left ventricle -> aorta
right ventricle
In the mammalian (and avian) heart, blood passes directly from the atria into the corresponding ventricles. So blood from the right atrium next enters the right ventricle.
Blood entering the right atrium is full of carbon dioxide; that is, it is deoxygenated. From there it enters the right ventricle and is pumped to the lungs, where the carbon dioxide is exchanged for oxygen via the process known as respiration (simply put, breathing). The now-oxygenated blood returns to the left atrium of the heart, progresses to the left ventricle, and is pumped throughout the body before returning go the right atrium.
both the lungs for purification
The left atrium of the heart receives oxygented blood from the pulmonary veins returning oxygenated blood to the heart.
When your blood comes back to your heart it goes into the right atrium.