Physiology is emerging as the central subject in medical science. With new revised curriculum of Medical Council of India (MCI), 2019, which has the recommendation for implementation of evidence-based, objective-oriented, clinically-focussed and skillbased integrated curriculum, physiology is the most suitable subject for such an evolutionary change in undergraduate medical profession in India. Physiology is the subject for complete integration with clinical and paraclinical subject, as Physiology provides the knowledge and basis of medical practice. In the new curriculum, Physiology as a subject will provide the link for integration among all the subjects. The present edition of the book is thoroughly revised in the light of new MCI 2019 guidelines for undergraduate medical curriculum. All major concepts and advances in physiology have been thoroughly incorporated in the text. The second edition of the book will fulfil the requirements and aspirations of all our readers.