Phagocytosis

Definition

Phagocytosis is a cellular process in which cells engulf and digest large particles, such as bacteria or dead cells. It is a crucial mechanism in the immune response to pathogens.

5 Must Know Facts For Your Next Test

1. Phagocytosis is primarily carried out by specialized cells called phagocytes, which include neutrophils and macrophages.
2. The process involves several steps: chemotaxis, adhesion, ingestion, digestion, and exocytosis of waste materials.
3. Phagocytosis plays a key role in both innate nonspecific host defenses and adaptive specific immunity.
4. Pathogens have evolved mechanisms to evade phagocytosis, such as producing capsules or toxins that inhibit the process.
5. Phagocytosis can trigger an inflammatory response that helps recruit additional immune cells to the site of infection.

Review Questions

• What are the main steps involved in the process of phagocytosis?
• How do pathogens evade phagocytosis and why is this significant?
• Which types of cells are primarily responsible for carrying out phagocytosis?

Related terms

Neutrophils:

A type of white blood cell that engulfs and digests bacteria and fungi.

Macrophages:

Large white blood cells found within tissues that perform phagocytosis on pathogens and dead cells.

Chemotaxis:

Movement of an organism or cell toward a chemical stimulus, often used to describe how immune cells locate sites of infection.