Pulmonary Artery Blood: Oxygenated or Deoxygenated?

The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs for oxygenation.

Pathway

1. Deoxygenated blood returns via the superior/inferior vena cava to the right atrium.
2. Passes through the tricuspid valve to the right ventricle.
3. Pumped through the pulmonary valve into the pulmonary trunk, then left and right pulmonary arteries.
4. In the pulmonary capillaries, CO₂ is exchanged for O₂.
5. Oxygenated blood travels via pulmonary veins to the left atrium.

Key Point

Arteries are defined by direction (away from the heart), not oxygen content. The pulmonary artery is the only artery carrying deoxygenated blood; the pulmonary veins are the only veins carrying oxygenated blood.