Over time and throughout all regions, history has been a discipline allowing an established order of knowledge, legacies and complex historical experiences of human beings. Consequently, knowing the history of civilizations, cultures and societies allows us to understand and rationalize this information and use the information to continue building a new reality. In this context, the objective of this work was to analyze the origin and meaning of the term diaphragm, and knowledge of the anatomy and functions of this muscle. Based on this knowledge and its path throughout history its current definition was constructed. In Homer's writings, the diaphragm was recognized as an anatomical structure that was not linked to any particular function and in the early physiological explanations of breathing, and did not play a role in the breathing process. Hippocrates and Plato marked a point of inflection in the definition of the term, since they described it as a structure that separated the thorax from the abdomen, relating it correctly with the meaning of the term diáphragma (diafragma), "separation". However, in the classical period of Greece, it was more frequently associated with Greek mythology and human spirituality, considering the diaphragm as the seat of thought. Another important milestone in the history of this muscle were the studies Galen through dissection in animals, and Vesalius in humans, where both describe the diaphragm and its functions in great detail, approaching the detail of the breathing process more closely. Finally, Testut structures the information in a manner that has been maintained to this day, and the only change has been in the dissemination of the information.
KEY WORDS: Diaphragm; History; Anatomy; Function.