Neutrophil

Definition

Neutrophils are a type of white blood cell essential for the innate immune response. They quickly act to ingest and destroy invading pathogens through a process called phagocytosis.

5 Must Know Facts For Your Next Test

1. Neutrophils are the most abundant type of white blood cells, making up about 50-70% of all white blood cells.
2. They are the first responders to microbial infection and play a crucial role in inflammation.
3. Neutrophils can release enzymes and toxic substances to kill pathogens, but this also damages surrounding tissues.
4. A high neutrophil count often indicates an active bacterial infection or other inflammatory conditions.
5. Neutrophils have a short lifespan, typically surviving only a few hours to a couple of days in the bloodstream.

Review Questions

• What percentage of white blood cells do neutrophils typically comprise?
• How do neutrophils contribute to the destruction of pathogens?
• What might a high neutrophil count indicate in a patient's blood test?

Related terms

Macrophage: A type of white blood cell that engulfs and digests cellular debris and pathogens, playing a key role in both innate and adaptive immunity.

Phagocytosis:

The process by which certain living cells called phagocytes ingest or engulf other cells or particles, such as pathogens.

Inflammation: A protective response involving immune cells, blood vessels, and molecular mediators that helps eliminate the initial cause of cell injury, clear out dead cells, and establish tissue repair.