| A | B |
|---|
| atria | the two upper chambers of the human heart |
| ventricles | the two lower chambers of the human heart |
| pulmonary circulation | the path of blood from the heart to the lungs and back to the heart |
| systemic circulation | the flow of blood from the heart to all the body tissues (except heart and lungs) and back to the heart |
| coronary circulation | the flow of blood to heart tissues |
| artery | a thick, elastic-walled vessel that moves blood away from the heart |
| vein | a vessel with one-way valves that moves blood toward the heart carrying wastes |
| capillary | a microscopic blood vessel that connects arteries and veins; nutrients, oxygen, and wastes are exchanged through their one-cell-thick walls |
| blood pressure | the force exerted by blood on the walls of the vessels; pressure is highest in the arteries and in young adults is normally 120 over 80 |
| atherosclerosis | a circulatory system disorder in which fatty deposits form on artery walls and resist blood flow |
| hypertension | a circulatory system disorder in which blood pressure is too high |
| heart murmur | a defect in the heart caused by an improperly functioning valve |
| plasma | the liquid part of blood, made mostly of water but also containing dissolved nutrients, minerals, and oxygen |
| hemoglobin | a chemical in red blood cells that carries oxygen to tissues, carries carbon dioxide to lungs, and gives red blood its color |
| platelet | an irregularly shaped cell fragment the helps blood clot |
| lymphatic system | collects fluid from body tissues and returns it to the blood through lymphatic capillaries and lymph vessels |
| lymph | fluid in body tissues made up of water, dissolved substances, and lymphocytes |
| lymphocyte | a type of white blood cell that fights disease-causing antigens by engulfing and digesting them |
| lymph node | bean-shaped structures throughout the body, that filter microorganisms and foreign material from lymph before it returns to blood |
