What do the different types of phagocytes do?

Neutrophils

The main functions of neutrophils include phagocytosis, degranulation, and the release of neutrophil extracellular traps, which are a form of nuclear material. 

The most abundant type of white blood cells in the body, neutrophils are among the first responders in the event of inflammation or infection in the body. On coming in contact with the invading pathogen, neutrophils release powerful enzymes that degrade the invader’s outer membrane. This makes it easier for the neutrophil to engulf and digest the pathogen, eliminating the threat.    

Monocytes

Monocytes perform two main functions. They kill the invading pathogen while also recruiting other blood cells to help destroy the invader and prevent infection. 

Monocytes circulate within the bloodstream, ready to be called to action. On detecting signs of infection or inflammation, they migrate from the blood into tissues, where they differentiate into macrophages, which are an even more powerful type of phagocyte. Monocytes live longer than most other types of immune scavengers, providing sustained defense. 

Macrophages

Macrophages are the ultimate cleanup crew of the immune system. They are capable of detecting, engulfing, and destroying pathogens including viruses, bacteria, fungi, and foreign particles as well as cancer cells. They also clean up dead and dying apoptotic cells in the body. 

After an injury, macrophages play a key role in wound healing and tissue repair by eliminating debris and dead cells from the damaged area. They are also responsible for antigen presentation, which helps activate the adaptive immune response, which provides long-term defense against infection.