Eosinophils

Definition

Eosinophils are a type of white blood cell that plays a critical role in the immune system, particularly in combating parasitic infections and mediating allergic reactions. They are part of the body's innate nonspecific host defenses as well as involved in certain adaptive immune responses.

5 Must Know Facts For Your Next Test

1. Eosinophils contain granules filled with enzymes and toxic proteins that can be released to kill parasites and modulate inflammatory responses.
2. They are important in defense against parasitic infections like helminths (worms) by releasing cytotoxic granules.
3. Eosinophils can contribute to tissue damage during chronic allergic conditions such as asthma due to their release of inflammatory mediators.
4. The presence of eosinophils is often elevated in blood tests during allergic reactions and certain infections.
5. Eosinophils interact with other immune cells, including T cells and mast cells, influencing both innate and adaptive immune responses.

Review Questions

• What role do eosinophils play in combating parasitic infections?
• How do eosinophils contribute to allergic reactions?
• Which other immune cells do eosinophils interact with to influence immune responses?

Related terms

Neutrophils: A type of white blood cell that is the first responder to microbial infection.

Mast Cells: Cells that play a key role in inflammation and allergic reactions by releasing histamine.

Adaptive Immunity: A subsystem of the overall immune system that provides long-term immunity through memory cells.