Interpretations of the Initial Phases of the Electrocardiogram with Special Reference to the Theory of Limited Potential Differences
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Oxygen Mine Rescue Apparatus And Physiological Effects On Users, Issues 82-96
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(Excerpt from Medical Studies in Aviation
The rebreathing...)
Excerpt from Medical Studies in Aviation
The rebreathing test finds its use, therefore, as a means of diagnosis, for it now becomes possible, when ever the flight surgeon suspects that air staleness is developing in one Of the men in his charge, to deter mine accurately the degree Of overtraining. F urther more, it appears3 that the use of the low oxygen test administered by means. Of the rebreathing apparatus may have a broader application in internal medicine as a measure of the functional power of the heart and circulation.
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Yandell Henderson was an American physiologist and toxicologist. He was a director of the Yale Laboratory of Applied Physiology at Yale University, and was noted, as a scientist, for developing new methods in resuscitation.
Background
Yandell Henderson was born on April 23, 1873 in Louisville, Kentucky, United States. He was the older of the two sons of Isham Henderson and Sally Nielsen (Yandell) Henderson. His father, a lawyer and engineer, built the first canal around the falls of the Ohio near Louisville and was part owner of the Louisville Journal, 1849-1868. His mother came of a Tennessee family with a strong medical tradition: his grandfather Lunsford Pitts Yandell helped found a medical school in Louisville in 1837; his uncle David Wendel Yandell was medical director of the Confederate Department of the West and afterward president of the American Medical Association.
Education
Henderson attended Chenault's School in Louisville and entered Yale College in 1891. In 1895 he began graduate work at Yale, studying physiological chemistry under Russell H. Chittenden, and in 1898 received his Ph. D.
His first published paper, "A Chemico-Physiological Study of Certain Derivatives of the Proteids, " written with Chittenden and his assistant Lafayette B. Mendel, appeared in the American Journal of Physiology in 1899.
Meanwhile, in 1898, Henderson, like other American chemists of the period, had gone to Germany to complete his education. At Marburg he studied under Albrecht Kossel and at Munich under Carl Voit.
Career
Upon his return in 1900, Henderson became an instructor in the physiological laboratory of the Yale Medical School (advancing to assistant professor in 1903 and professor in 1911) and began research on the physiology of the circulation. The results of his experiments led him to question current theories of the action of the heart and, in turn, to investigate the physiological role of carbon dioxide in respiration. Theories of mammalian circulation at that time were based chiefly on studies of the frog, the favorite experimental animal since the days of William Harvey.
Henderson--a leader in shifting laboratory instruction in physiology from the study of the frog to that of mammals--used dogs and cats as subjects and devised new instruments which revealed hitherto unrecognized and distinctive characteristics of the mammalian heartbeat. This work led him to challenge the accepted theory that the return of blood to the heart was produced by auricular contraction. Instead, he proposed the existence of a "venopressor mechanism" and characteristically tried to discover the nature of this mechanism by studies on animals in which an acutely low blood pressure (shock) had been produced by various means. To his surprise he found that increasing the rate of artificial respiration aggravated the circulatory failure. Since forced ventilation depletes the blood of carbon dioxide, he associated the loss with the accelerated fall in blood pressure. This observation became the basis for Henderson's famous "acapnia theory of shock, " which he first set forth in the British Medical Journal of December 22, 1906. This theory was received with incredulity, and, as Henderson admitted in his autobiographical Adventures in Respiration, "it was doubtful whether I could have succeeded had not J. S. Haldane and his collaborators, at the most convenient moment for me (1905), published their epoch-making studies on the part that carbon dioxide plays in the normal control of respiration. " In an address in 1909 ("Fatal Apnoea and the Shock Problem, " Johns Hopkins Hospital, Bulletin, August 1910) he pointed out the role of severe pain in stimulating overventilation and described experiments in which an anesthetized animal was made to rebreathe a certain amount of its own expired air so as to maintain a proper level of carbon dioxide in the blood and thus prevent respiratory failure.
This and later work led the way to the clinical use of a mixture of carbon dioxide and oxygen after anesthesia. The "acapnia" theory was eventually discarded, but not before its author had used it as the basis for his pioneer studies of ventilation, noxious gases, and resuscitation. Henderson actively supported Haldane in his dispute with Joseph Barcroft over the important question of whether the lungs could actively secrete oxygen when the oxygen content of the air was decreased. To test the theory (eventually disproved by Barcroft), and to determine the mechanisms involved in man's adaptation to low atmospheric pressures, Henderson in 1911 joined Haldane and others in an Oxford-Yale expedition to Pikes Peak in Colorado. In a laboratory set up at some 14, 000 feet they performed experiments whose results later became the basis for understanding the physiological disturbances suffered by aviators at high altitudes. Henderson also undertook studies of ventilation for the United States Bureau of Mines.
In 1920, in collaboration with Howard Wilcox Haggard, he determined standards of ventilation which were used in the design of the Holland Tunnel under the Hudson River and which became generally accepted for similar tunnels throughout the world. The two men also made a thorough investigation of the mechanism and treatment of poisoning by noxious gases--notably carbon monoxide--which was summarized by Henderson's most important book (written with Haggard), Noxious Gases and the Principles of Respiration Influencing Their Action (1927). In 1922 the Henderson-Haggard inhalator for use in asphyxia became standard equipment for rescue squads and has had wide use in stimulating breathing in the newborn.
Henderson's demonstration of the effectiveness of carbon dioxide in the relief of anoxia led him into further disputes with biochemists over the relationship of anoxia to acidosis. Professor Lawrence J. Henderson of Harvard had introduced into physiology the concept of an acid-base balance, according to which an excessive accumulation of carbon dioxide and other acids in the body must accompany asphyxiation, so that the administration of carbon dioxide in asphyxia would aggravate the condition.
Henderson vigorously defended his own view and termed as "pseudo-acidosis" the condition described by L. J. Henderson. The chemical vagueness of this definition made it unacceptable to biochemists. Henderson, however, believed with Haldane in a complexity of the animal economy beyond the reach of contemporary physical science, as he stated at the beginning of his important paper on the "Physiological Regulation of the Acid-Base Balance of the Blood" (Physiological Reviews, April 1925) and throughout his Adventures in Respiration (1938).
During World War I, Henderson served as chief of the physiological section of the war-gas investigations conducted by the Bureau of Mines. As chairman of the medical research board of the Aviation Section of the army Signal Corps (1917-1918), he organized a laboratory to test the highest altitude a particular individual could safely withstand.
When Henderson opposed the reorganization of Yale University in 1920, he was removed from his professorship at the medical school, and in 1921 he was appointed professor of applied physiology in the graduate school. With no teaching duties, he continued his investigation of respiration and circulation. He also undertook other assignments. Much dissatisfaction was felt at Yale at this time because many younger faculty members were underpaid and were expected to supplement their incomes by summer employment. Appointed to study the problem, Henderson produced (with Maurice R. Davie) a forthright document, Incomes and Living Costs of a University Faculty (1928), that made bold recommendations for improving the salary scale.
He became professor emeritus at Yale in 1938. In 1944, at the age of seventy, he died of cancer at Scripps Memorial Hospital, San Diego, California. His remains were cremated and the ashes buried in East Lawn Cemetery, Williamstown, Massachussets, the home of his son-in-law.
As a young man Henderson had shown some interest in public affairs. He was a delegate to the Progressive National Convention in 1912 and ran for Congress on that party's ticket in 1912 and 1914. During the 1920s he became concerned with the prohibition question. Regarding distilled liquors as dangerous and habit-forming narcotics, he proposed discouraging their use through high taxes, and his testimony before a Congressional committee was partly responsible for the limits set in the 1933 legislation that permitted the sale of beer containing 3. 2 percent alcohol by weight.
Membership
A member of many professional societies, Henderson was elected to the National Academy of Sciences in 1923 and to the American Philosophical Society in 1935.
Connections
Henderson married Mary Gardner Colby of Newton Center, Massachussets, on April 2, 1903. Their children were Malcolm Colby and Sylvia Yandell.