Arterial blood Arterial blood Arterial blood is the oxygenated blood in the circulatory system found in the pulmonary vein, the left chambers of the heart, and in the arteries. It is bright red in color, while venous blood is dark red in color (but looks purple through the translucent skin). It is the contralateral term to "venous blood". Framed in the cardiac cycle, often historically accredited to the Wiggers diagram, arterial blood has just passed through the lungs and is ready to boost oxygen to sustain the peripheral organs. The essential difference between venous and arterial blood is the curve of the
Azygos vein and usually occurs simultaneously with situs inversus, asplenia, or polysplenism, persistent left superior vena cava (SVC), and congenital pulmonary venolobar syndrome. Azygos and hemiazygos continuation of the IVC is rare especially when it is not associated with congenital heart disease. The Greek root "zyg" refers to a pair. 'A-' means "not". Thus, "azygos" means "unpaired". The azygos vein is unpaired in that there is only one in the body, mostly on the right side. While there is the hemiazygos vein and its accessory on the left side of the body, they are considered tributaries of the azygos vein rather than