What is the function of the great vessels of the heart?
Your great vessels are a vital part of your circulatory system. There are two main circulatory system circuits: the pulmonary circuit and the systemic circuit. Here’s a breakdown of what those circuits do and the role your great vessels play:
Pulmonary circuit
Your pulmonary circuit sends blood between your heart and lungs. First, oxygen-poor blood travels from your heart to your lungs. There, it receives oxygen and gets rid of waste. This refreshed blood then travels back to your heart.
The role of your great vessels
- Main pulmonary artery: Carries oxygen-poor blood from your heart’s right ventricle into your left and right pulmonary arteries. These arteries carry the blood to your lungs.
- Pulmonary veins: Carry oxygen-rich blood from your lungs to your heart. All of your pulmonary veins (usually four) directly empty into your heart’s left atrium.
Systemic circuit
Your systemic circuit sends blood between your heart and the rest of your body. First, oxygen-rich blood leaves your heart. It circulates throughout your body, where it delivers oxygen, nutrients and hormones to your organs and tissues. It also picks up waste. This blood, now low on oxygen and containing waste products, travels back to your heart.
The role of your great vessels
- Aorta: The first part of your aorta, called your ascending aorta, carries oxygen-rich blood directly out of your heart’s left ventricle. From there, blood flows into your aorta’s many branches to nourish the rest of your body.
- Superior vena cava: This large vein delivers oxygen-poor blood from your upper body into your heart’s right atrium.
- Inferior vena cava: This large vein delivers oxygen-poor blood from your lower body into your heart’s right atrium.
Your great vessels are similar to other blood vessels in your body. The arteries carry blood away from your heart, and the veins carry blood toward your heart. However, there’s a crucial difference.
Normally, arteries contain oxygen-rich blood, and veins contain oxygen-poor blood. However, there are two exceptions to this rule: your pulmonary arteries carry oxygen-poor blood, and your pulmonary veins carry oxygen-rich blood.
