A fluid in the body that delivers oxygen and other materials to cells and removes carbon dioxide and other wastes.

A type of blood cell that picks up oxygen in the lungs and delivers it to cells throughout the body.

A blood vessel with strong walls that carries blood AWAY from the heart.

A blood vessel that carries blood back to the heart.

A narrow blood vessel that connects arteries and veins, and where material can move in and out of bloodstream.

A type of blood cell that helps the body fight pathogens (things that can cause diseases).

Cell fragments that help the body form blood clots that stop bleeding in blood vessels.

The upper chambers of the heart that receive blood entering the heart.

The lower chambers of the heart that pump blood out of the heart.

The thick tissue that separates the right and left sides of the heart.

Flaps of tissue that prevent blood from flowing backwards.