Blood vessel prevent backflow as a result of a decrease in blood pressure as the blood passes through the circulatory system. There are various kinds of blood vessels: They are roughly grouped as "arterial" and "venous", determined by whether the blood in it is flowing "away from" (arterial) or "toward" (venous) the heart. The term "arterial blood" is nevertheless used to indicate blood high in oxygen, although the pulmonary artery carries "venous blood" and blood flowing in the pulmonary vein is rich in oxygen. This is because they are carrying the blood to and from the lungs, respectively, to be oxygenated. Blood
Blood red wound, and it does not change color upon exposure to air. The color "blood red", therefore, covers both these states: the darker deoxygenated color and the brighter oxygenated one. Also, dried blood often has a darker, rust-colored quality: all dried blood has been oxygenated and then desiccated, causing the cells within it to die. This blood is often darker than either shade of red that can be seen in fresh blood. In the RGB color spectrum blood red often consists only of the color red, with no green or blue component; in the CYMK color model blood red has no