Disease Prevention

Neutrophils:

• circulate in blood and spread into tissue during an infection
• rapid reaction force of immune system- rush to infected are and try to kill the pathogens
• don't last long
• after engulfing the bacteria they die- sometimes accumulate to form pus 
• number increases during an infection
• pour out of bone marrow, circulate in blood and leave through capillary walls to damaged tissue
• die soon after
• can digest way through to linings to get to tissue

Monocytes:

• pass out of blood stream and into tissue where they form macrophages
• long-lived cells
• special role in specific defence system by processing and 'presenting' antigens to lymphocytes
• some migrate
• others stationary in certain tissues- Kidneys/Lungs/Brain/Liver/Spleen/Lymph nodes (where a lot of antigen presentation occurs

Dendritic Cells

• long processes which give large surface areas to interact with pathogens and lymphocytes
• often found throughout body
• once they gave ingested some foreign material they migrate and take the material to the lymph nodes