Ivan Pavlov was a biologist who studied the physiology of the digestion and blood circulation. Pavlov is also very known by his discovery of the “conditioned reflex”.

Ivan Petrovich Pavlov was born on september 14, 1849, at Ryazan (Russia). He went to the St. Petersburg university to study natural science. There Pavlov became an enthusiastic physiologist. In 1883 he presented his doctor's thesis about “the centrifugal nerves of the heart”.

In the institute of experimental medicine, Pavlov made brilliants investigations on the physiology of the digestion using alive animals. This was possible thanks to the use of surgically created fistulas, a better and much more human method than the vivisection, used until them. So, Pavlov showed the important role of the nervous system in the regulation of the digestive glands: for example, when a dog sees food, the brain of the animal orders to its salivary glands that secrete saliva.

Pavlov discovered that if a external stimulus is presented repeatedly, immediately before the food, the animal will begin to salivate only with the external stimulus. Pavlov called this answer a “conditioned reflex”.

In 1904, Pavlov won the Noble prize of physiology and medicine. He continued working actively in his lab until his death, at the age of 87 (1936).

This Pavlov picture has been made by Sergi Quiñones Oliva (Othello).

More information:

• Nobel e-Museum.
• A Science Odissey.
• Muskingum College.
• A game about conditioned reflex.