Stem Cells     Red Blood Cells       White Blood Cells

Platelets        Plasma        Blood Types & Activity

Bloodology

		The Video The My Blood, Your Blood program features state-of-the-art 3-D science animation, and exciting video microscopy. The story of how blood works in your body is explored by our engaging young host.  He explains the history of blood, the composition of blood in our bodies - red cells, white cells, platelets, plasma, stem cells - and the different activities of each blood component.  The whole combination makes up the bloodstream.  Click on the links above to discover more.
		History of Blood A Roman doctor named Galen believed that blood was formed in the liver and was unaware that the heart pumped blood through the arteries and veins. It wasn’t until the 1600’s that it was discovered blood circulates throughout the body, pumped by the heart.
		White Blood Cells Defend the Body Against Disease & Infection White blood cells are the body’s defense system. There are three types of white blood cells: granulocytes, lymphocytes and monocytes.  They all fight infection from bacteria, viruses and microbes that can cause diseases.
		Blood Circulation & Respiration One complete round trip will take, on average only 30 to 45 seconds. And, even less during exercise. The human body has so many miles of blood vessels inside of it that they could encircle the earth twice, then a little bit more.

		Platelets & Blood Vessel Repair Platelets are small pieces of cell material, or cytoplasm, whose job it is to plug holes in vessel walls. They look like two plates stuck together, but when they are helping to form a clot, they change shape. In the event of a tear inside a blood vessel wall millions of platelets respond to the injury, throwing themselves over the cut. They stick to the wound's edges and to each other to form a plug that slows the loss of blood within three to five minutes.
		Blood Types & Activity There are four different human blood groups: O, A, B and AB. Groups A and B have certain inherited antigens, or markers, on their red blood cells. The most common blood types in the United States are A Rh positive and O Rh positive… about 72 percent of the population is one or the other. The rarest blood type is AB Rh negative.