| anemia |
a medical condition caused by having too few red blood cells or red blood cells that are not working properly. People with anemia may be pale, feel weak, and have difficulty breathing. |
| antibody |
a protein in blood that reacts to particular toxic substances by neutralizing or destroying them. Antibodies provide immunity against these toxic substances. |
| aorta |
the main artery of the body. The aorta carries blood from the left side of the heart to all parts of the body except the lungs. |
| artery |
a blood vessel that carries blood away from the heart. [1/2 definitions] |
| atrium |
either of the two upper compartments of the heart; auricle. Blood returning from the body flows into the atria, which pump the blood to the ventricles, the lower compartments of the heart. [1/2 definitions] |
| bite |
of insects or similar small creatures, to break into the skin of (a human or other mammal) in order to feed on blood. [1/10 definitions] |
| bleed |
to lose blood. [1/3 definitions] |
| blood bank |
a place where blood is collected and stored for later use by people who have lost too much blood. |
| bloodshed |
the spilling of blood through injury or violence. |
| bloodshot |
red and irritated because of enlarged blood vessels. |
| bloodstream |
the blood flowing in a living thing. |
| blood vessel |
any of the tubes in the body through which the blood moves. Arteries, veins, and capillaries are types of blood vessel. |
| bloody |
covered with or leaking blood. [2/3 definitions] |
| capillary |
a tiny blood vessel joining the end of an artery to the beginning of a vein. |
| circle |
a group of people who are related by blood or have the same interests. [1/5 definitions] |
| circulation |
the movement of blood through the arteries and veins of the body. [1/3 definitions] |
| circulatory |
of or pertaining to the circulatory system, the system of bodily organs, including the heart, arteries, and veins, that send blood and lymph throughout the body and return it to the heart. |
| circulatory system |
a system in the body made up of the heart, blood vessels, blood, and lymph vessels that carries blood and lymph around the body. |
| clot |
a thick lump or mass of liquid, such as blood. [1/2 definitions] |
| cold-blooded |
having blood whose temperature changes with the temperature of the air or water. Animals such as fishes, snakes, and lizards are cold-blooded. [1/2 definitions] |
| corpuscle |
a cell that moves freely in the blood. Red and white blood cells are corpuscles. |