What You Already Know Write YES if you agree with the statement or NO you disagree. 1. The brain serves as the control center of all the functions of the body. 2. The main function of the heart is to pump blood through the blood vessels by repeated rhythmic contractions. 3. The lungs are the respiratory organs that are involved in the exchange of gases. 4. The kidneys are the two bean-shaped organs located at the back of the abdominal cavity. 5. The liver is the filtering machine of the body located on the right side of the abdominal cavity.​