| A | B |
|---|
| blood | fluid connective tissue of the circulatory system; consists of blood cells and plasma |
| heart | multi-chambered, muscular organ that pumps blood throughout the body |
| capillary | microscopic blood vessel that carries blood between an artery and a vein, allowing the exchange of substances between the blood and interstitial fluid |
| artery | vessel that carries blood away from the heart to other parts of the body |
| vein | vessel that returns blood to the heart |
| lymph | fluid similar to interstitial fluid that circulates in the lymphatic system |
| pulmonary circuit | circuit of blood flow that carries blood between the heart and lungs |
| systemic circuit | circuit of blood flow that carries blood between the heart and the rest of the body |
| aorta | artery that carries blood directly from the heart to the rest of the body |
| atrium | heart chamber that receives blood returning to the heart from other parts of the body |
| ventricle | heart chamber that pumps blood out of the heart |
| valve | flap of tissue in the heart that prevents blood from flowing in the wrong direction |
| pacemaker | specific region of the heart that sets the rate at which the heart contracts |
| AV node (atrioventricular node) | region of the heart that causes the ventricles to contract when stimulated by impulses from the pacemaker |
| systolic pressure | first number of a blood pressure reading; measures the pressure on artery walls when heart ventricles contract |
| diastolic pressure | second number of a blood pressure reading; measurement of the pressure on artery walls when the heart is relaxed |
| plasma | liquid portion of blood made up of water, dissolved salts, proteins, and other substances |
| red blood cell | blood cell containing hemoglobin, which transports oxygen molecules; also called an erythrocyte |
| hemoglobin | iron-containing protein in red blood cells that carries oxygen for delivery to cells |
| white blood cell | blood cell that functions in defending the body against infections and cancer cells; also called a leukocyte |
| platelet | fragment of a blood cell originating in the bone marrow that is involved in blood clotting |
| plaque | deposits of cholesterol, calcium, and fat that build up on artery walls and can lead to cardiovascular disease |
| cardiovascular disease | illness of the heart and/or blood vessels |
| atherosclerosis | narrowing of the arteries that results from a buildup of plaque |
| heart attack | condition that occurs when an artery becomes blocked, disrupting blood flow to the heart |
| arteriosclerosis | condition that occurs when plaque hardens on artery walls |
| hypertension | condition of having a blood pressure of 140/90 or higher for an extended period; also called high blood pressure |
| stroke | damage to brain tissue resulting from a clot blocking blood flow to the brain |
| pharynx | upper portion of the throat; the junction of the alimentary canal and the trachea |
| epiglottis | flap of tissue that covers the trachea during swallowing, preventing food from entering the lungs |
| larynx | voicebox; contains the vocal cords |
| trachea | in humans, tube between the larynx and bronchi through which air travels to the lungs; also called the windpipe |
| bronchus | one of the two tubes connecting the trachea to each lung |
| lung | organ consisting of sponge-like tissue that exchanges oxygen and carbon dioxide with the blood |
| bronchiole | thin tube that branches from a bronchus within a lung |
| alveolus | one of millions of tiny sacs within the lungs where gas exchange occurs |
| diaphragm | sheet of muscle that forms the bottom wall of the chest cavity; contracts during inhaling and relaxes during exhaling |
| emphysema | respiratory disease in which alveoli lose their elasticity, leading to difficulty breathing |
