Hess, Walter Richard Rudolf (1881-1973), a Swiss physiologist (scientist who studies how living things function), made important discoveries about how parts of the brain control and coordinate the working of body organs. For these discoveries, Hess received half of the 1949 Nobel Prize for physiology or medicine. The Portuguese scientist Antonio Moniz received the other half of the prize for his discoveries in brain surgery.
Hess was born in Frauenfeld, Switzerland. He studied medicine at the University of Zurich in Switzerland, receiving his M.D. in 1906. Hess qualified as a surgeon and developed a successful career as an ophthalmologist. In 1912, however, he gave up this career and became a research assistant. He studied hemodynamics, (the flow and pressure of blood) and conducted research into the relationship between respiration and the regulation of blood pressure and heart rate. In 1917, he was appointed director of the physiology department at the University of Zurich.
From 1925 onward, Hess became interested in the autonomic nervous system, the part of the nervous system that controls involuntary body processes. He studied structures at the base of the brain of cats and dogs, and developed techniques for stimulating certain areas of the brain with needle electrodes. He demonstrated that the hypothalamus, the lower part of the brain, controls body temperature, blood pressure, sexual arousal, sleep, anger, respiration, and other functions.