Two Types of Phagocytes

By Munmun Agarwal

A phagocyte is a type of white blood cell that protects the body by ingesting harmful foreign particles, bacteria and other pathogens – organism that causes disease in another organism. Phagocytes also play a crucial role in the disposal of dead and dying cells of your body. A number of different cell in your body are considered phagocytes. The most common types are neutrophils and monocytes.



Neutrophils

Neutrophils are the smallest and most abundant white blood cells in the blood. Neutrophils possess a nucleus divided into 2 to 5 lobes. Neutrophils obtain most of their energy from glycogen in the cytosol – liquid found inside cells. They are the main component of pus cells, accounting for its whitish or yellowish appearance. The average lifespan of non-activated neutrophil is 5.4 days.

Neutrophils Work

Neutrophils are the fist line of defense against bacteria that invade tissues and blood, meaning it is the first cell type to be recruited to sites of infection. They are fast-acting, arriving at the site of injury within minutes. Neutrophils undergo a process called chemotaxis, which allows them to reach the site of infection by directing their movement according to certain chemicals in the environment. After reaching the pathogen, neutrophils engulf it and enclose the infection in a phagosome -- a cellular compartment in which pathogenic micro-organisms can be killed and digested.

Monocytes

Monocytes are a type of white blood cells and play an important role in protecting the human body against disease by identifying and killing pathogens. Monocytes are fairly variable in size and appearance. They are the largest white blood cells in the body. The nucleus can be round or kidney-shaped.

Monocytes Work

Monocytes are made in the bone marrow -- the flexible tissue found in the interior of bones. Monocytes circulate briefly in blood for about one to three days, then migrate into tissues where they differentiate further to become macrophages. Macrophages are a type of white blood cell, and are responsible for protecting tissues from foreign substances.

About the Author

Munmun Agarwal has been writing professionally since 2008 and has completed her master's degree in biotechnology from Agra University. She completed her research work at Dayalbah University, Agra.