We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What are Phagocytes?

By Greer Hed
Updated Mar 03, 2024
Our promise to you
The Health Board is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At The Health Board, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A phagocyte is a type of white blood cell that helps the human body fight off infection and disposes of dead or dying somatic cells. Phagocytes rid the body of bacteria and other pathogens via an ingestion process called phagocytosis. During phagocytosis, phagocytes engulf and kill microbes using a variety of different methods. There are two types of phagocyte, professional and non-professional. The professional cells are equipped with receptor molecules that are attracted to certain chemicals that signal the presence of an infection.

One of the important roles filled by phagocytes is the disposal of cells that have undergone apoptosis, or programmed cell death. Dead or dying cells are disposed of by nonprofessional phagocytes. The cells put out chemical signals that allow the phagocyte to detect their decline, so it can then ingest the dying cells using phagocytosis. Professional phagocytes also use phagocytosis to dispose of bacteria and other microbes. Viruses cannot be killed using this process, as they use phagocytosis to invade white blood cells and infect the rest of the body.

Phagocytosis begins with the phagocyte surrounding the microbe or dead cell. When the harmful cell is completely engulfed in the phagocyte, it is trapped inside a chamber called a phagosome or phagocytic vesicle. Enzyme-containing organelles called lysosomes then fuse with the phagosome, creating a structure called a phagolysosome, in which the trapped particle is killed and digested.

Phagocytes can kill microbes using either intracellular or extracellular processes. The most efficient killing process takes place within the phagocyte and depends on molecules that contain oxygen found within the white blood cell. Oxygen radicals undergo various chemical reactions in the presence of enzymes found in the phagolysosome. These chemical reactions convert the oxygen to hydrogen peroxide and singlet oxygen, a less stable form of oxygen molecule. Hydrogen peroxide is an antiseptic and disinfectant that kills microbes.

There are also types of intracellular killing that do not rely on the presence of oxygen. Antimicrobial proteins in the phagolysosome can also kill bacteria by attacking their bacterial membranes. Binding proteins called lactoferrins deprive bacteria of iron that the microbes need to grow and reproduce. Extracellular killing occurs outside the cell, and depends on the presence of a protein called Interferon-gamma. This protein activates a professional phagocyte called a macrophage so it produces another protein called tumor necrosis factor that causes cell death.

Professional phagocytes come in many types. There are neutrophils, which are the most numerous type of phagocyte and are usually the body's first line of defense against infection. Macrophages are usually stationary, or "fixed," when they reach maturity, guarding vital areas of the body like the liver, lungs, and brain. Dendritic cells receive their name from growths called dendrites that they produce. Monocytes, aside from performing phagocytosis, also replenish macrophages and dendritic cells in a healthy body.

The Health Board is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.

Discussion Comments

The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.

The Health Board, in your inbox

Our latest articles, guides, and more, delivered daily.