First blood enters into the top right chamber, the right atrium, stop there for a moment then drops down into the bottom right chamber, the right ventricle. When your heart beats the used blood in the bottom right chambers shoots out of the heart and through an artery into you lungs.
indicator - (chemistry) a substance that changes color to indicate the presence of some ion or substance; can be used to indicate the completion of a chemical reaction or (in medicine) to test for a particular reaction.
A number or quantity that records a directly observable value or performance. All measures have a unit attached to them: inch, centimeter, dollar, liter, etc. In contrast, an indicator is an indirect measure or a predictor (such as a leading Indicator) of performance. If you want to make a big splash in the business world sometimes you need to take a drastic measure to show you are serious.