What are macrophages?

• Macrophages are white blood cells that identify intruders through the molecules that cover the intruders' surfaces (antigens)¹


• They are part of the "nonspecific immune system," and are the first to react to foreign invaders³
• Their response time does not change no matter how many times a microbe attempts to infect the body


• These white blood cells eat the microbes and carry the antigens back to "home base" in the lymph nodes¹


• Lymph nodes are bean-sized organs scattered throughout your body and act as gathering spots for the white blood cells¹


• Here, the macrophages "sound the alarm" to other white cells (helper T cells) by showing them the antigens from the microbe. That way, helper T cells can recognize them.¹
  
• Helper T cells are a type of white cell called lymphocytes