| A | B |
|---|
| cardiovascular system | The body system that consists of the heart, blood vessels, and blood, and that carries needed substances to cells and carries waste products away from cells |
| heart | A hollow, muscular organ that pumps blood throughout the body |
| atrium | Each of the two upper chambers of the heart that receives blood that comes into the heart |
| ventricle | A lower chamber of the heart that pumps blood out to the lungs and the body |
| valve | A flap of tissue in the heart or a vein that prevents blood from flowing backwards |
| pacemaker | A group fo cells located in the right atrium that sends out signals that make the heart muscle contract and that regulates heatbeat rate |
| arteries | A blood vessel that carries blood away from the heart |
| capillaries | A tiny blood vessel where substances are exchanged between the blood and the body cells |
| vein | A blood vessel that carries blood back to the heart |
| aorta | The largest artery in the body |
| force | A push or a pull exerted on an object |
| coronary arteries | An artery that supplies blood to the heart itself |
| diffusion | The process by which molecules move from an area in which they are highly concentrated to an area in which they are less concentrated |
| pressure | The force that something exerts over a given area |
| blood pressure | The pressure that is exerted by the blood against the walls of the blood vessels |
| sphygmomanometer | An instrument that measures blood pressure |
| plasma | The liquid part of the blood |
| red blood cell | A cell in the blood that takes up oxygen in the lungs and delivers it to cells elsewhere in the body |
| hemoglobin | An iron-containing protein that binds chemically to oxygen molecules and makes up most of a red blood cell |
| white blood cells | A blood cell that fights disease |
| platelet | A cell fragment that plays an important part in forming blood clots |
| fibrin | A chemical that is important in blood clotting because it forms a net of tiny fibers that traps red blood cells |
| blood transfusion | The transference of blood from one person to another |
| lymphatic system | A network of veinlike vessels that returns the fluid that leaks out of blood vessels to the bloodstream |
| lymph | The fluid that the lymphatic system collects and returns to the blood stream |
| lymph node | A small knob of tissue in the lymphatic system that filters lymph |
| atherosclerosis | A condition in which the artery wall thickens as a result of buildup of fatty materials |
| heart attack | A condition in which the blood flow to a part of the heart muscle is blocked, which causes heart cells to die |
| hypertension | A disorder in which a person's blood pressure is consistently higher than normal |
