Ivan Pavlov was born on the 14th of September 1849 in Ryazan, a small city in central Russia, into a religious family of Christian believers. His father, Peter, was a village priest and the family expected Ivan to become a priest too. He received his first education at the local church school and then entered the theological seminary.

Soon Ivan Pavlov got inspired by the works of Charles Darwin, D. Pisarev and I. Sechenov, and abandoned the theological seminary. He decided to devote his life to science instead of religion and entered the University of St. Petersburg, where he studied chemistry and physiology, which remained the key interest of his further life. As a university student he wrote a work on the physiology of the pancreatic nerves for which he was awarded with a golden medal. In 1875 Pavlov graduated from the university with a degree of Candidate of Natural Sciences. After graduation received another education at the Academy of Medical Surgery and graduated from it with a golden medal. Pavlov concentrated on research in the spheres that he was most interested in: the nervous system, physiology of digestion, and blood circulation. His works brought him fame and he was appointed professor of physiology at the Imperial Medical Academy.

The work that made Pavlov famous in psychology began as a study of the digestion processes. He was researching the digestive process in dogs focusing on the interaction between salivary secretion and the action of the stomach. After a series of experiments with dogs he came to the conclusion that salivary secretion and the action of the stomach were closely connected by reflexes in the autonomic nervous system. Pavlov wanted to check whether external stimuli could affect salivation and for thiat purpose he rang a metronome every time when giving the experimental dogs food. After a while the dogs, that used to salivate only when they saw and ate their food, began to salivate when the metronome sounded, even if no food was given to them. In 1903 Pavlov published the results of the experiments calling them a "conditioned reflex," different from an innate reflex because the latter was an inborn trait and could not be learnt. The work was called “The Experimental Psychology and Psychopathology of Animals”. He also found that conditioned reflexes could be supressed if the stimulus gives a result different from what the experimental animals used to expect from it. If the metronome sounds repeatedly and no food is given to the dogs, they eventually stop salivating when the sound appears.

Very soon Pavlov received world acclaim and recognition as well as great popularity within his native country – in the USSR and then in Russia. In 1901 Pavlov was elected an honorary member of the Russian Academy of Sciences, in 1904 he was awarded with a Nobel Prize, and in 1907 he was elected Academician of the Russian Academy of Sciences; in 1912 he was given an honorary doctorate at Cambridge University and later became an honorary member of different scientific organizations abroad and in 1915 he was even was awarded with the Order of the Legion of Honour.

Ivan Pavlov was married to Seraphima Karchevskaya with whom they had three sons - Vladimir, Victor and Vsevolod. Pavlov died in Leningrad (St. Petersburg) on the 27th of February 1936.

Link to Ivan Pavlov's Nobel Lecture:
http://nobelprize.org/medicine/laureates/1904/pavlov-lecture.html