Corneille Jean Francois Heymans (1892 - 1968) was a Belgian physician, university professor, pharmacologist, physiologist, toxicologist, and winner of the Nobel Prize in Physiology or Medicine in 1938 "for his discovery of the role of the sinus and aortic mechanisms in the regulation of respiration". In the laboratory of the Institute of Pharmacology and the J.F. Heymans Institute (named after Corney's father), he and his colleagues conducted complex experiments on the pathophysiology of the cardiovascular and respiratory systems, in particular the influence of the former's reflexes on the frequency and rhythm of heart rate, blood pressure, and respiratory rate.
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Prior to Heymans' research, scientists believed that the cardiovascular and respiratory centers in the medulla oblongata regulate blood flow, blood pressure, and gas concentration in the blood, and that these respiratory processes occur in accordance with the immediate physiological needs of the body and without the participation of nervous system reflexes. In the period from 1924 to 1927, Heymans and his colleagues showed that respiratory rate is regulated by nervous system reflexes transmitted through the vagus and depressor nerves.
First, Heymans discovered the participation of nerve reflexes originating in the reflexogenic aortic zone in the respiratory system's response to changes in blood pressure.
Then, studying the existence of nerve reflexes between the carotid sinus and the vascular and respiratory centers in the medulla oblongata, he and his father discovered the presence of baroreceptors in the carotid sinus.
In 1926. Heymans and his colleagues showed that the carotid sinus and aortic areas also contain chemoreceptors, which are similar in structure to baroreceptors. They then demonstrated that the concentration of both respiratory gases and hydrogen ions is maintained in balance by nervous system reflexes that combine vascular chemoreceptors, the respiratory center in the medulla oblongata, and the lungs.
Further research by Heymans showed that partial pressure of oxygen - not the oxygen content of hemoglobin - is a very effective stimulus for vascular chemoreceptors, which explained why respiratory rate does not change in anemia and carbon monoxide poisoning.
In 1925, Heimans succeeded his father as rector of the University of Ghent and the Heimans Institute.
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