Ivan Petrovich Pavlov
Article abstract: Pavlov is best known for developing the theory of conditioned reflexes, which he demonstrated by teaching a dog to salivate when it heard a bell. He also performed important experiments to determine the connection between human behavior and the nervous system; he won the Nobel Prize in Physiology or Medicine in 1904 for his work on the digestive tract.
Ivan Petrovich Pavlov was born on September 26, 1849, in Ryazan, Russia, the eldest son of parents of peasant stock. His father, Peter Dmitrievich Pavlov, was a village priest, who emphasized family, hard work, reading, and education. His mother, Varvara Ivanovna Pavlov, supported his father in these efforts. Pavlov was born into a large family of eleven children, six of whom died in childhood.
Pavlov’s education began when he was seven years old; at home, he was taught to read and write. When he was ten years old, he had an accident that weakened him physically, and the effects of the accident lasted throughout the remainder of his childhood. When he was eleven years of age, his parents entered him in the second grade at the local parish school to begin his formal education. Four years later, in 1864, he entered the theological seminary of Ryazan, where he received a classical education of the day in preparation for the priesthood. It was there that he developed his first genuine interest in science. In 1870, he decided not to become a priest and left the seminary to enroll at the University of St. Petersburg, where he studied science. There he pursued inorganic chemistry, organic chemistry, and physiology under such renowned professors as Dmitry Mendeleyev, Aleksandr Butlerov, and Ilya Tsion.
Pavlov completed his studies at the University of St. Petersburg in 1875 and entered the Medico-Chirurgical Academy (later renamed the Military Medical Academy), where he worked as a laboratory assistant while earning his medical degree. In 1877, he published his first work of substance; the subject was the control of blood circulation by reflexes. He completed his course of study and became a full physician in 1879 at thirty years of age. Four years later, in 1883, he completed his dissertation. In the meantime, he met and married Serafima Karchevokaya, a friend of Fyodor Dostoevski. Theirs was a good, supportive marriage.
Pavlov’s three main areas of investigation and physiological inquiry include blood circulation, food digestion, and conditioned reflexes. These three matters provide a convenient way of discussing his life’s achievements, as he took these up in turn.
After completing his medical dissertation in 1883, Pavlov and his wife spent two years in Germany, where Pavlov studied cardiovascular physiology under Carl Ludwig and gastrointestinal physiology under Rudolf Heidenhain. Upon his return to St. Petersburg in 1886, Pavlov began his first major, sustained research; his efforts were directed to understanding cardiac physiology and regulating blood pressure. His success is greatly attributable to his surgical skills. Pavlov was able to enter a catheter into the femoral arteries of dogs and cats with little pain and no anesthesia; thus, he was able to observe and record the effects of various stimuli on the blood pressure of the animals. By working carefully and repeatedly, he was eventually able to determine which nerves controlled the pulsation and magnitude of the heartbeat. Dissection further assisted him in verifying his findings, as did the use of drugs, cutting nerves, and making permanent openings into the digestive tract.
At about the time Pavlov completed his work on blood circulation, he was appointed to a position at the Military Medical Academy, where he had earlier been a medical student. First, he served as an instructor of pharmacology; he then became director of a new surgical department of the school called the Institute of Experimental Medicine, where he conducted his scientific studies for the next several decades. To his credit, Pavlov was consistently humane in his treatment of his subjects, that is, his dogs and cats. His leadership provided for a system under which pain during surgery and other study was minimized, and the animals received the best of care after procedures were completed.
Pavlov had already been at work on the digestive tract before he finished his work on blood circulation. For some ten or twelve years after the formation of the Institute of Experimental Medicine under his direction in 1891, Pavlov and his researchers determined a number of things about the digestive system. They were able to do so primarily because Pavlov perfected a surgical technique of creating a kind of separate stomach in dogs, which made it possible for investigators to monitor secretions and other activity of the digestive process. He was able to determine the function of nerves in controlling digestion, and he discerned a wealth of other information about processes of the alimentary canal. In 1888, he discovered the secretory nerves of the pancreas; in 1889, he studied the function and activity of other gastric glands. His work on digestion continued for decades, but in 1897 he published his findings on the principal digestive glands. This...
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