Physiology (/ËŒfɪziˈɒlÉ™dÊ’i/; from Ancient Greek φÏσις (physis), meaning 'nature, origin', and -λογία (-logia), meaning 'study of'[1]) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical and physical functions in a living system. According to the classes of organisms, the field can be divided into medical physiology, animal physiology, plant physiology, cell physiology, and comparative physiology.Central to physiological functioning are biophysical and biochemical processes, homeostatic control mechanisms, and communication between cells.Physiological state is the condition of normal function, while pathological state refers to abnormal conditions, including human diseases.The Nobel Prize in Physiology or Medicine is awarded by the Royal Swedish Academy of Sciences for exceptional scientific achievements in physiology related to the field of medicine. Human physiology seeks to understand the mechanisms that work to keep the human body alive and functioning,[4] through scientific enquiry into the nature of mechanical, physical, and biochemical functions of humans, their organs, and the cells of which they are composed. The principal level of focus of physiology is at the level of organs and systems within systems. The endocrine and nervous systems play major roles in the reception and transmission of signals that integrate function in animals. Homeostasis is a major aspect with regard to such interactions within plants as well as animals. The biological basis of the study of physiology, integration refers to the overlap of many functions of the systems of thehuman body, as well as its accompanied form. It is achieved through communication that occurs in a variety of ways, both electrical and chemical.Changes in physiology can impact the mental functions of individuals. Examples of this would be the effects of certain medications or toxic levels of substances. Change in behavior as a result of these substances is often used to assess the health of individuals.Much of the foundation of knowledge in human physiology was provided by animal experimentation. Due to the frequent connection between form and function, physiology and anatomy are intrinsically linked and are studied in tandem as part of a medical curriculum.