The questions leads towards which physiological important gases the blood contains.
When the blood moves TO the lungs it has both CO2 (carbondioxide) and O2 (oxygen). However the level of oxygen is lower, and the level of CO2 is higher than with blood coming from the lungs.
The circulatory system moves blood to the lungs. This part of the system is called the pulmonary circulation.
oxygenated blood
Blood is de-oxygenated when it it pumped into the lungs, and after going through the lungs, is now oxygenated.
As blood moves through the lungs, oxygen is exchanged for carbon dioxide. Oxygen diffuses from the air in the lungs into the blood, increasing the oxygen level in the blood. Conversely, carbon dioxide diffuses from the blood into the air in the lungs, decreasing the carbon dioxide level in the blood.
The left atrium receives blood from the lungs. This blood moves into the left ventricle to be sent out to the body.
heart
Blood moves to the right ventricle where it is pumped to the lungs.
In the lungs. The blood is pumped from the right side of the heart to the lungs. Air moves into the trachea, the bronchi and finally to the alveoli. From the alveoli oxygen diffuses into the microcapilaries (small blood vessels) of the lungs.
The heart is a pump that moves all blood in the body.
The process by which blood moves between the heart and the lungs is called pulmonary circulation. Deoxygenated blood is pumped from the heart to the lungs through the pulmonary arteries, where it picks up oxygen and releases carbon dioxide. The oxygenated blood then returns to the heart via the pulmonary veins.
The lungs are the primary organs that fill blood with oxygen. Oxygen from the air is inhaled into the lungs, where it moves into the bloodstream through tiny blood vessels called capillaries surrounding the lungs' air sacs.
through respiratory membrane via diffusion