a type of blood vessel that carries blood AWAY from the heart and to other parts of the body.
the smallest kind of blood vessel.
a type of blood vessel that carries blood from the cells back to the heart.
an opening that allows blood to flow in one direction but stops it from flowing in the other direction.
a sticky,thick fluid that traps dust,germs and other things that may be in the air.
a tube that carries air from the throat to the lungs.
tubes that branch out from the bronchi.
tiny thin-walled pouches in the lungs.
a tube in the throat with rings of muscle that help you swallow food.