| A | B |
|---|
| arteries | vessels that carry blood AWAY from the heart |
| veins | vessels that carry blood BACK to the heart |
| capillaries | the smallest vessels; location of exchanges |
| lymph | fluid that is forced out of blood |
| arterioles | small arteries |
| venules | small veins |
| plasma | the watery substance in blood |
| red blood cells | transport oxygen |
| white blood cells | attack bacteria; kill infections |
| platelets | irregularly-shaped fragments that allow blood to clot |
| septum | the thick wall that separates the two sides of the heart |
| heart attack | occurs when an area of the heart is deprived of oxygen |
| stroke | occurs when an area of the brain is deprived of oxygen |
| atherosclerosis | the hardening of arteries due to plaque build-up |
| hemoglobin | iron-containing protein found in red blood cells |
