Pavlovian Reflex

Ivan Petrovich Pavlov ( rus, Ива́н Петро́вич Па́влов, , p=ɪˈvan pʲɪˈtrovʲɪtɕ ˈpavləf, a=Ru-Ivan_Petrovich_Pavlov.ogg; 27 February 1936), was a Russian and Soviet experimental neurologist, psychologist and physiologist known for his discovery of classical conditioning through his experiments with dogs.

Education and early life

Ivan Petrovich Pavlov, the first of eleven children, was born in Ryazan, Russian Empire. His father, Peter Dmitrievich Pavlov (1823–1899), was a village Russian orthodox priest. His mother, Varvara Ivanovna Uspenskaya (1826–1890), was a devoted homemaker. As a child, Pavlov willingly participated in house duties such as doing the dishes and taking care of his siblings. He loved to garden, ride his bicycle, row, swim, and play gorodki; he devoted his summer vacations to these activities. Although able to read by the age of seven, Pavlov was seriously injured when he fell from a high wall onto a stone pavement. As a result of the injuries he sustained he did not begin formal schooling until he was 11 years old.

From his childhood days, Pavlov demonstrated intellectual curiosity along with an unusual energy which he referred to as "the instinct for research". Inspired by the progressive ideas which Dmitry Pisarev, a Russian literary critic of the 1860s, and Ivan Sechenov, the father of Russian physiology, were spreading, Pavlov abandoned his religious career and devoted his life to science. In 1870, he enrolled in the physics and mathematics department at the University of Saint Petersburg to study natural science.

Pavlov attended the Ryazan church school before entering the local theological seminary. In 1870, however, he left the seminary without graduating to attend the university at St. Petersburg. There he enrolled in the physics and math department and took natural science courses. In his fourth year, his first research project on the physiology of the nerves of the pancreas won him a prestigious university award. In 1875, Pavlov completed his course with an outstanding record and received the degree of Candidate of Natural Sciences. Impelled by his overwhelming interest in physiology, Pavlov decided to continue his studies and proceeded to the Imperial Academy of Medical Surgery. While at the academy, Pavlov became an assistant to his former teacher, Elias von Cyon. He left the department when de Cyon was replaced by another instructor.

After some time, Pavlov obtained a position as a laboratory assistant to Konstantin Nikolaevich Ustimovich at the physiological department of the Veterinary Institute. For two years, Pavlov investigated the circulatory system for his medical dissertation. In 1878, Professor S. P. Botkin, a famous Russian clinician, invited the gifted young physiologist to work in the physiological laboratory as the clinic's chief. In 1879, Pavlov graduated from the Medical Military Academy with a gold medal award for his research work. After a competitive examination, Pavlov won a fellowship at the academy for postgraduate work.

The fellowship and his position as director of the Physiological Laboratory at Botkin's clinic enabled Pavlov to continue his research work. In 1883, he presented his doctor's thesis on the subject of ''The centrifugal nerves of the heart'' and posited the idea of ''nervism'' and the basic principles on the trophic function of the nervous system. Additionally, his collaboration with the Botkin Clinic produced evidence of a basic pattern in the regulation of reflexes in the activity of circulatory organs.

Influences

He was inspired to pursue a scientific career by D. I. Pisarev, a literary critique and natural science advocate of the time and I. M. Sechenov, a Russian physiologist, whom Pavlov described as "the father of physiology".

Career

After completing his doctorate, Pavlov went to Germany, where he studied in Leipzig with Carl Ludwig and Eimear Kelly in the Heidenhain laboratories in Breslau. He remained there from 1884 to 1886. Heidenhain was studying digestion in dogs, using an exteriorized section of the stomach. However, Pavlov perfected the technique by overcoming the problem of maintaining the external nerve supply. The exteriorized section became known as the Heidenhain or Pavlov pouch.

In 1886, Pavlov returned to Russia to look for a new position. His application for the chair of physiology at the University of Saint Petersburg was rejected. Eventually, Pavlov was offered the chair of pharmacology at Tomsk University in Siberia and at the University of Warsaw in Poland. He did not take up either post. In 1890, he was appointed the role of professor of Pharmacology at the Military Medical Academy and occupied the position for five years. In 1891, Pavlov was invited to the Institute of Experimental Medicine in St. Petersburg to organize and direct the Department of Physiology.

Over a 45-year period, under his direction, the institute became one of the most important centers of physiological research in the world. Pavlov continued to direct the Department of Physiology at the institute, while taking up the chair of physiology at the Medical Military Academy in 1895. Pavlov would head the physiology department at the academy continuously for three decades.

Starting in 1901, Pavlov was nominated over four successive years for the Nobel Prize in Physiology or Medicine. He did not win the prize until 1904 because his previous nominations were not specific to any discovery, but based on a variety of laboratory findings. When Pavlov received the Nobel Prize it was specified that he did so "in recognition of his work on the physiology of digestion, through which knowledge on vital aspects of the subject has been transformed and enlarged".

It was at the Institute of Experimental Medicine that Pavlov carried out his classical experiments on the digestive glands, which would eventually grant him the aforementioned Nobel prize. Pavlov investigated the gastric function of dogs, and later, homeless children, by externalizing a salivary gland so he could collect, measure, and analyze the saliva and what response it had to food under different conditions. He noticed that the dogs tended to salivate before food was actually delivered to their mouths, and set out to investigate this "psychic secretion", as he called it. Experiments on orphaned children, involving drilling a hole in their cheeks and applying electric shocks, were continued by his assistant Nikolay Krasnogorsky.

Pavlov's laboratory housed a full-scale kennel for the experimental canines. Pavlov was interested in observing their long-term physiological processes. This required keeping them alive and healthy to conduct chronic experiments, as he called them. These were experiments over time, designed to understand the normal functions of dogs. This was a new kind of study, because previously experiments had been "acute," meaning that the dog went through vivisection which ultimately killed the canine in the process.

A 1921 article by S. Morgulis in the journal ''Science'' was critical of Pavlov's work, raising concerns about the environment in which these experiments had been performed. Based on a report from H. G. Wells