As Gray states "...he established a vital bridge between physiology and psychology, two subjects that were virtually isolated from each other when his career began but are now almost at the point of fusion; and he converted the programmatic sketches of nineteenth century philosophical materialism into an experimental science whose methods and results now deeply affect our lives. (Gray, Ivan Pavlov 1)
             Ivan Petrovich Pavlov was born in 1849 to a poor priest in Ryazan which is about 150 miles east of Moscow, Russia. He started high school at age eleven and then went to a local seminary. Pavlov is regarded as one of the founding fathers of modern experimental psychology. In 1870, Pavlov went to St. Petersburg University to study science. In his third year at the university he decided that his career would be physiology. He finished college in 1875 and went on to study at Medico-Surgical Academy. Pavlov took charge of the newly opened laboratory for animal experiments at the academy. Pavlov died in 1936.
             Pavlov first did experiments that involved blood pressure and innervation of the heart. Pavlov wanted to investigate the way in which blood vessels adapt to different volumes of blood. He trained dogs to lie still and then he would connect an artery to a pressure gauge. Then he could measure blood pressure and find out that blood volume remains the same even during eating or fasting. These findings led Pavlov to more important work on the digestive system. The blood pressure experiment took only a simple operation. More complicated surgery was needed for experiments on the digestive system. This problem led to the book The Work of the Digestive Glands. Pavlov's findings in this book established the science of gastroenterology. Pavlov's main focus in digestion was the secretion of the different digestive juices in response to food. His work on the digestive system won him the Nobel Prize in 1904. As Gray notes ...