What type of blood do veins primarily transport?

Veins primarily transport deoxygenated blood back to the heart, having collected it from the body where oxygen has been delivered to tissues and carbon dioxide has been picked up. In the systemic circulation, veins are responsible for carrying blood that has a lower oxygen content due to the metabolic processes of the body. This deoxygenated blood is then sent to the heart, from where it is pumped to the lungs for reoxygenation.

While pulmonary arteries carry deoxygenated blood away from the heart to the lungs, veins perform the vital function of returning this blood to the heart. Understanding this process is crucial for comprehending how circulatory system dynamics operate and how oxygen exchange occurs within the body.