Skeletal muscle acts as a secretory organ, releasing signaling molecules that can act locally and on other tissues, with some signals influenced by contraction.

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Pedersen and Febbraio review skeletal muscle as a secretory organ and describe myokines with autocrine, paracrine, and endocrine effects, including communication with adipose tissue, liver, pancreas, bone, and brain.

This does not establish that every bout of movement produces clinically meaningful systemic effects or that myokines explain all benefits of exercise.

The manuscript phrase is broader and more accessible. The public record names the specific secretory-organ mechanism.

Broad, mature principles of human biology, behavior, or regulation supported across a substantial body of research.

Sources are listed according to the role they play in this claim. One source may provide direct support, another may explain a mechanism, establish a limitation, or prevent an interpretation from becoming broader than the evidence allows.

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This claim connects to the following parts of the Human OS architecture. The module labels locate the claim inside the framework; they do not imply that the research source validates the architecture itself.