Path of RBC into/ through RT side of heart, and to the lungs.

The left side of the heart would survive if it took its oxygen from the left chamber, but the right side wouldn't do well. The right atrium handles the unhealthy oxygen poor blood from everywhere in the body and moves it down to the right ventricle. From there, the heart forces the unhealthy blood into the pulmonary artery which gives it to the lungs.