endogeneous

Endogenous refers to something originating or produced from within a system, organism, or cell. This is in contrast to exogenous, which describes something originating from outside. The term is widely used across various scientific disciplines.

In biology, endogenous substances are those produced by the body itself. For example, hormones like insulin and adrenaline are endogenous. The body's own immune cells are also endogenous. This internal production is crucial for regulating physiological processes and maintaining homeostasis.

In medicine, endogenous factors contributing to disease are those that arise from within the patient's body. This could include genetic predispositions or internal metabolic imbalances. Understanding endogenous causes is vital for diagnosis and treatment.

The concept extends to chemistry, where endogenous reactions are those occurring within a system without external catalysts or reactants. In economics, endogenous variables are those whose values are determined by the model itself, as opposed to exogenous variables which are determined outside the model. The principle of originating from within remains consistent across these diverse applications.