Now that you have explored the Human Body Adventure, try the following self-quiz to check what you have learned. If you didn't know the answer to a question, click the answer to go back to the page that explores the specific topic. Blood is not always bright red. In fact, it is only bright red half of the time through half of the body.
Blood is bright red only after it leaves the lungs where it picks up oxygen.
However, once the oxygen has been released throughout the body, blood becomes a darker purplish-red color. When cut, blood immediately turns bright red when exposed to the oxygen in the air. If this page doesn't look right, you need to upgrade to the new version of Flash Player .