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Innate immunity
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Innate immunity is the part of your defenses that responds right away, without asking who it is dealing with. It does not wait to recognize a specific enemy: it reacts to any pathogen, meaning any germ capable of causing disease, or to damage to your own cells. It is the guard already standing watch before it knows who walked in. It begins with things as simple as the skin, the mucous membranes, saliva and tears.
Behind those barriers there are cells on watch: neutrophils and macrophages, which eat germs; dendritic cells; natural killer cells; and mast cells. To detect danger they use pattern recognition receptors, such as toll-like receptors, which do not read an identity but a signal that something is wrong.
There are also molecules that work on their own. Lysozyme and defensins break apart germ membranes, and complement either marks them so they get eaten, which is called opsonization, or bursts them outright. And the phagocytes, by displaying pieces of the germ, connect this fast defense to adaptive immunity, the kind that does learn and remember.
In brief
Innate immunity is the immediate, nonspecific defense against pathogens or cell damage, and it begins with the skin, mucous membranes, saliva and tears.
It is the guard already standing watch before it knows who walked in.
Neutrophils, macrophages, dendritic cells, natural killer cells and mast cells patrol the tissues and detect danger through pattern recognition receptors such as toll-like receptors.
Lysozyme and defensins break apart microbial membranes, while complement promotes opsonization and lysis; phagocytes, by presenting antigens, bridge innate and adaptive immunity.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingPhysiology, Immune Response, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated