PMNs

Definition

PMNs, or polymorphonuclear leukocytes, are a type of white blood cell characterized by a segmented nucleus. They play a crucial role in the immune response by combating bacterial infections.

5 Must Know Facts For Your Next Test

1. PMNs are also known as neutrophils and are the most abundant type of white blood cells in humans.
2. They are one of the first responders to migrate towards infection sites through chemotaxis.
3. PMNs kill bacteria through phagocytosis, degranulation, and the production of neutrophil extracellular traps (NETs).
4. In bacterial meningitis, an elevated PMN count in cerebrospinal fluid is a key diagnostic indicator.
5. PMNs have a short lifespan, typically surviving only a few hours to days in the bloodstream.

Review Questions

Related terms

Phagocytosis:

The process by which cells, like PMNs, engulf and digest pathogens and debris.

Chemotaxis:

The movement of an organism or cell towards or away from a chemical stimulus.

Neutrophil Extracellular Traps (NETs): Web-like structures released by neutrophils to trap and kill microbes.