selvreaktiv

Selvreaktiv is a term used in Norwegian and Swedish to describe something that activates itself or reacts without external input. As an adjective, it covers processes, devices, or biological phenomena that begin or respond autonomously, often through internal feedback, thresholds, or self-sustaining loops.

Etymology: from selv ('self') and reaktiv ('reactive'). In everyday usage it can mean self-activating (selvaktiverad; selvaktiverende) or self-reactive, depending on the context. The precise sense is determined by the field: engineering tends toward self-activation, immunology toward autoreactivity.

In technology and engineering, selvreaktiv describes systems that initiate operation without human input, such as self-starting motors, self-activating sensors, or control circuits that respond to internal states. In energy harvesting and automation, self-activation reduces external control needs and can improve reliability in remote or autonomous systems.

In biology and medicine, selvreaktiv or autoreaktiv refers to molecules or cells that recognize self-antigens. Autoreactive immune components play a central role in autoimmune diseases; they are typically regulated by tolerance mechanisms but may emerge under genetic or environmental triggers.

The term is used across disciplines, and its precise meaning depends on the context.