Emergence of the concept of endocrine function and endocrinology.

Endocrinology as a scientific discipline is relatively new. The term "hormone" was introduced in 1905, and "endocrinology" was introduced in 1909. However, its origins are ancient and rooted in the millennia-old practice of organotherapy, from its archaic religious beginnings, through early attempts to explain the integrated functions of the body by the philosophically sound but scientifically mysterious humors of Greek medicine, to its incorporation into the pharmacopoeias of the eighteenth century. The concept of internal secretions germinated in the anatomical discoveries of the Renaissance, which described ductless glands, and after the discovery of the circulation, came the suggestion of "internal secretions" into blood as organ "emanations which are useful to the body." The principal events that led to the emergence of endocrinology occurred in the latter half of the nineteenth century, from the experimental studies of Claude Bernard (1813-1878), the clinical observations of Thomas Addison (1793-1860), and the combined experimental and clinical studies of Brow-Sequard (1817-1894). The first decades of the twentieth century saw in sequence the isolation of crude organ extracts, their preparation as hormones in pure crystalline form, and their ultimate use in the cure of diseases that had haunted mankind thereto.