Blood Anatomy Poster
Blood
4 parts of blood
Plasma
Platelets
Red Blood Cells
White Blood Cells
White Blood Cells are abbreviated WBC but they are technically the Leukocytes. There are 5,000 to 10,000 WBC per microliter of blood. The WBC are the only blood cell that contains a nucleus and thus DNA. WBC obviously belong to the circulatory system, but they are also part of the immune system. Their main function is to fight disease and foreign invaders - anything from a virus to a splinter to a donated organ. There are many different types of WBCs. In general, once a foreign substance enters the body, WBC identify it, surround it, and destroy it. Once the WBC has encountered a foreign Antigen, it secretes an Antibody. The Antibody is a protein that has a specific shape that fits like a key into the lock of the foreign Antigen. If the foreign substance invades the body a second time, the WBC can very quickly check their database by using the Antibodies. The image below shows RBC, WBC, and the two together to compare sizes.