Circulatory

• Artery - carry oxygenated blood away from the heart
• Capillaries - one-cell thick vessels where gas exchange takes place
• Vein - carries deoxygenated blood back to heart
• aorta - largest artery
• vena cava - largest veins (anterior and posterior)
• Pulmonary arteries - the only arteries that carry deoxygenated blood
• Pulmonary veins - the only veins that carry oxygenated blood