Phagocytic Cells & Phagocytosis Process

What activates the second line of defense?

It activates when pathogens bypass the first line.

What do neutrophils do?

Perform phagocytosis and release chemicals.

What do eosinophils do?

Attack parasites via phagocytosis and toxic granule release.

Where are dendritic cells found and what do they do?

In most tissues; they act as antigen-presenting cells (APCs).

What are macrophages and where are they found?

Phagocytic APCs found in most tissues.

What are the two types of macrophages?

Wandering and fixed macrophages.

Give examples of fixed macrophages.

Microglia (CNS) and Kupffer cells (liver).

What is chemotaxis in phagocytosis?

Movement of phagocytes toward chemical signals from pathogens.

What is adherence in phagocytosis?

When a phagocyte binds to a pathogen's surface.

What is opsonization?

Coating of a pathogen with complement or antibodies to enhance adherence.

What happens during ingestion in phagocytosis?

The phagocyte engulfs the pathogen into a phagosome.

What is digestion in phagocytosis?

The phagosome fuses with a lysosome, breaking down the microbe.

How are pathogens killed inside phagocytes?

By enzymes and reactive oxygen species.

What is a respiratory burst?

Release of reactive oxygen species by phagocytes to destroy ingested microbes.