| A | B |
|---|
| blood vessels | the tubes in the cardiovascular system |
| heart | muscular pumping organ that pushes blood out to the body |
| arteries | large vessels that carry blood away from the heart |
| veins | large vessels that carry blood back to the heart |
| capillaries | tiny blood vessels where the blood slows down and exchange of materials happens |
| thoracic cavity | the heart and the lungs are located in this area of the body |
| apex | the longest part of the heart that touches the diaphragm |
| diaphragm | the muscle that cuts the torso in half - the apex of the heart sits right above this |
| pericardium | the slippery sac of connective tissue around the heart |
| pericardial fluid | fluid that keeps the pericardium lubricated to help prevent friction |
| endocardium | smooth tissue lining the inside of the heart |
| myocardium | heart muscle |
| atrium | top chamber of the heart |
| ventricle | bottom chamber of the heart |
| atrioventricular valves | these keep blood from flowing back into the atrium |
| semilunar valves | prevent blood from flowing back into the heart after it has been pumped out by the ventricles |
