Innate immune system

Definition

The innate immune system is the body's first line of defense against pathogens, providing rapid but non-specific responses. It includes physical barriers, immune cells, and various proteins that identify and eliminate invaders.

5 Must Know Facts For Your Next Test

1. The innate immune system responds within minutes to hours after infection.
2. Key components include physical barriers like skin, phagocytic cells like macrophages, and proteins such as cytokines.
3. Unlike the adaptive immune system, the innate immune system does not have memory; it responds the same way to repeated infections.
4. Pattern recognition receptors (PRRs) on innate immune cells recognize pathogen-associated molecular patterns (PAMPs).
5. Inflammation is a hallmark response of the innate immune system to infection or injury.

Review Questions

• What are the main components of the innate immune system?
• How does the response time of the innate immune system compare to that of the adaptive immune system?
• What role do pattern recognition receptors (PRRs) play in the innate immune response?

Related terms

Adaptive Immune System: A part of the immune system that develops specific responses to pathogens and retains memory for faster future responses.

Phagocytosis: The process by which certain cells engulf and digest microorganisms and cellular debris.

Cytokines: Small proteins released by cells that have a specific effect on interactions and communications between cells during an immune response.