| A | B |
| myocardium | thick middle muscle layer of the heart; pumps blood through the circulatory system |
| ventricle | lower chamber of the heart that pumps blood out of the heart |
| atrium | upper chamber of the heart that recieves and holds blood that is about to enter the the ventricle |
| pulmonary circuation | pathway of circulation between the heart and the lungs |
| systematic circulation | pathway of circulation bewteen the heart and the body |
| valve | flap of connnective tissue between the atrium and the ventricle, or in a vein, that prevents backflow of blood |
| aorta | large blood vesselin mammals through which blood travels after it leaves the left ventricle |
| artery | large blood vessel that carries blood from the heart to the tissue of the body |
| vein | a blood vessel that returns blood to the heart |
| capillary | smalllest blood vessel; brings nutrients and oxygen to the tissues and absorbs carbon dioxide and waste products |
| atherosclerosis | condition in which fatty deposits called plaque build up on the inner walls of the arteries |
| plasma | straw-colored fluid that makes up about55% of blood |
| hemoglobin | iron-containing protein in red blood cells that transports oxygen from the lungs to the tissues of the body |
| lymph | fluid lost by the blood into surrounding tissue |
| platelet | cell fragment released by bone marrow that helps in blood clotting |
| pharynx | muscular tube that connects the mouth with the rest of the digestive tract and serrves as a pathway for air and food |
| trachea | windpipe; tube through which air moves |
| larynx | structure in the throat containing the vocal cords |