Here are five easy ways to say: "Veins carry darker red blood that has less oxygen back to the heart." First, a quick reminder: veins are the tubes that bring blood back to the heart, and that blood looks darker because it has given its oxygen to the body.
- Veins bring darker red blood with less oxygen back to your heart.
- Veins carry blood that is darker and has less oxygen to the heart.
- Blood that has less oxygen and looks darker travels in veins back to the heart.
- Veins return darker, low-oxygen blood to the heart.
- The veins send darker red blood, which has less oxygen, back to the heart.
Pick any one you like — they all mean the same thing but use slightly different words.