| A | B |
|---|
| Blood vessel | A tube that carries blood through the body. There are three major types of blood vessels: arteries, veins, and capillaries |
| Circulatory system | The system of blood vessels, blood, and the heart responsible for the transportation of substances through the body |
| Plasma | The liquid component of blood. Plasma consists of water, dissolved substances, and blood proteins |
| Blood protein | A protein carried in the plasma of the blood. Blood proteins include antibody, hormones, and clot-forming proteins, as well as other kinds |
| Antibody | A type of blood protein that recognizes and tries to destroy foreign matter (such as bacteria) in the body |
| Immune system | The parts of the body involved in defending against disease-causing organisms. For example, antibodies and white blood cells help destroy bacteria and other foreign matter |
| Hormone | A type of blood protein that acts as a chemical messenger. Hormones are produced in one part of the body (a gland) and often affect other parts |
| Clot-forming blood protein | A set of proteins that form a hard plug (clot) wherever a blood vessel has been damaged |
| Red blood cell | A small, disk-shaped blood cell that contains hemoglobin, a protein that combines with oxygen. This allows red blood cells to carry oxygen in the blood |
| Hemoglobin | A protein contained in red blood cells that picks up oxygen in areas of high concentration and releases the oxygen in areas of low concentration |
| White blood cell | A blood cell that forms part of the body’s immune system. Some types of white blood cells detect and consume foreign particles such as bacteria |
| Platelet | A small, cell-like fragment found in the blood. Platelets contain the chemicals that start blood clotting. They break open and release these chemicals wherever a blood vessel is damaged |
| Artery | A thick-walled blood vessel that carries blood away from the heart. |
| Capillary | A tiny, thin-walled blood vessel that carries blood close to body cells for the exchange of supplies and wastes. Capillaries connect arteries to veins |
| Valve | Flaps of tissue found in the circulatory system that act to prevent the backward flow of blood |
| Pulse | The rhythmic surge of blood passing a certain place in an artery. A pulse occurs after each beat of the heart |
| Heart rate | The number of times the heart beats in a minute |
| Deoxygenated blood | Blood in which the red blood cells have given up their oxygen to body cells and so are no longer carrying large amounts of oxygen |
| Atrium (plural: atria) | One of the two chambers at the top of the heart. The right atrium receives deoxygenated blood from the body. The left atrium receives oxygenated blood from the lungs |
| Oxygenated blood | Blood in which the red blood cells are carrying large amount of oxygen |
| Ventricle | One of the two chambers at the bottom of the heart. The right ventricle sends deoxygenated blood to the lungs. The left ventricle sends oxygenated blood to the body |
| Heart attack | A failure of the blood supply to the muscles of the heart. The heart muscles cannot work properly and may be damaged or die |
| Atherosclerosis | A disease in which cholesterol and other fats stick to the inner surface of arteries, reducing the amount of blood moving through the artery. Also called “hardening of the arteries.” |
