What are leukocytes and where are they produce and stored in the body? How do they travel around the body during the

Question: What are leukocytes and where are they produce and stored in the body? How do they travel around the body during the immune system's response to the invasions of a foreign substance?
- Keywords:
  body,
  immune system response,
  invasion,
  leukocyte,
  substance
Asked by 454sysb37 to Carmen, Daniel, Laura, Noel, Steph on 12 Mar 2015.
- Carmen Denman answered on 12 Mar 2015:
  
  Hello 454sysb37,
  
  Great question, other scientists may have a better answer but I will attempt one! Leukocyte is a general term for white blood cell. A white blood cell protects the body against infection and fight infection when it occurs. They are bigger than red blood cells. Normally our blood contains anywhere from 5,000 to 10,000 leukocytes per cubic millimeter! I had to google that factoid 🙂 So they are ciruclating around our bodies via the blood stream all the time. When infection is present their numbers sky rocket, and they also become more mobile in our bodies to target infection and move back and forth between the blood, lymph, and tissues.
  
  Leukocytes are able to engulf things like bacteria, fungi, and viruses. Interestingly, they are also detoxifiers of toxic proteins that may result from allergic reactions and cellular injury; and immune system cells.
  
  So, very useful cells!
  
  Carmen

Question: What are leukocytes and where are they produce and stored in the body? How do they travel around the body during the immune system's response to the invasions of a foreign substance?