Physiology is the most fascinating and ancient branch of science. It is fascinating because, it unfolds the mystery of complicated functional aspects of the individual organs of the body. It is ancient because, it exists ever since the origin of life. Even before knowing the lanugauge,culture and society, man knew the hunger, thirst, pain and fear which are the basics of physiology. Physiology is defiened as the study of functions of various systems and different organs of the body. The basic physiological functions include provision of oxygen and nutrients, removal of metabolites, other waster products, maintenance of blood pressure and body temperature, hunger, thirst, locomotor functions, special sensoty functions, reproduction and higher intellectual functions like learning and memory.