Hippocrates’ idea that four humors naming, “Blood”, “Phlegm”, “Yellow bile” and “Black bile” are present in human body, forms the basis of the humoral theory of disease. The nature of diet and the extent of digestion determine the quantity and predominance of the type of humor produced in liver, which is considered to be the site of origin of all humors. Every humor has its own nature; Blood is hot and moist, phlegm is cold and moist, yellow bile is hot and dry, and black bile is cold and dry. Similarly, every human has a unique humoral constitution, which is maintained by the presence of a “Vital Force”. Malfunctioning of this vital force results in an imbalance of the humors, and thus illness. This implies that, a harmony of humors is health. The theory of humors was opposed by Erasistratus, who searched for the cause of disease in the physical parts of body rather than in humors. Galen, whose knowledge of anatomy was largely based upon the dissection of mammals, brought the ancient Greek medical knowledge to an end.
After this, the study of normal and pathological anatomy started to emerge. Scholars of this age attributed the changes observed in pathological tissues to various disease processes. This was the dawn of a new era in the study of the nature of disease. New discoveries in the field of anatomy opened the door to a new rainbow of ideas, helping explain things which were till then, beyond human understanding. The advancements in the field of anatomy proved beneficial to the surgeons. The treatment of gunshot wounds markedly improved. Caesarean sections became an option for the delivering mothers. Harvey’s discovery of blood circulation marks an important point in the history. All modern intravenous techniques rely on this discovery. It not only makes delivery of drugs possible, it also provides a mean for taking samples from the body for analysis outside the body i.e. Laboratory Analysis. Jean Pacquet discovered the thoracic duct, which in turn lead to an understanding of the lymphatic system. The use of microscope led Marcello Malpighi to discover blood vessels and blood corpuscles. These blood cells were later classified and studied in greater depths, which led to an improved understanding of the blood. The field of Hematology thus evolved.
References
Williams, H. S., & Williams, E. H. (1904). A History of Science: In Five Volumes (Vol. 1). New York: Harper.
Cassell, E. J. (2004). The Nature of Suffering and the Goals of Medicine (2nd ed.). New York: Oxford University Press.
Crowley, L. V. (1997). Introduction to human disease. The Jones and Bartlett series in health sciences. Boston, Mass: Jones and Bartlett.
