You have a right and left atrium on either side of the heart. The right atrium receives deoxygenated blood from the superior and inferior vena cava. The left atrium receives oxygenated blood from the lungs. Arteries are flexible. The smallest veins are venules. You have four valves in your heart, which I will list in order: Tricuspid, Pulmonary or Pulmonic, Bicuspid or Mitral, and the Aortic. Now lay down, slowly count down from 100, and I will begin.