The subject of the book by Vesalius that changed the field of medicine is anatomy.
The book by Vesalius that changed the field of medicine is called De humani corporis fabrica libri septem which was published in 1543. The book is a comprehensive study of human anatomy that provided a detailed description of the human body's structure and the functions of its various organs. The book was highly influential in the development of modern medicine, as it challenged many of the traditional views on anatomy and physiology that had been held for centuries.
Vesalius based his book on his own observations, including dissections of human cadavers, rather than relying on the works of earlier authorities. This approach allowed him to make many groundbreaking discoveries about the human body's structure and function, including the discovery of the true structure of the heart and the role of the lungs in respiration.
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