French Anatomist, Physician and Pathologist
The great French anatomist and physician Marie-François-Xavier Bichat is remembered for his pioneering work in anatomy and histology. Bichat's attempt to create a new system for understanding the structure of the body culminated in the tissue doctrine of animal anatomy. Bichat's approach involved studying the body in terms of organs, which were then dissected and analyzed into their fundamental structural and vital elements, called "tissues." Bichat was the son of a respected doctor and was expected to enter the same profession. After studying medicine at Montpellier, Bichat continued his surgical training at the Hôtel Dieu in Lyons. The turmoil caused by the French Revolution, however, forced him to leave the city for service in the army. In 1793 he was able to resume his studies in Paris and became the disciple of the eminent surgeon and anatomist Pierre-Joseph Desault (1744-95). When his mentor died, Bichat spent several years editing the fourth volume of Desault's Journal of Surgery, to which he added a biographical memoir of the author.
Bichat began to give lectures in 1797 and became physician to the Hôtel Dieu in 1800. One year later, he was appointed professor. Completely dedicated to anatomical and pathological research, Bichat essentially lived in the anatomical theater and dissection rooms of the Hôtel Dieu, where he performed at least 600 autopsies in one year. In 1802 he became ill with a fever and died before completing his last anatomical treatise.
Tissue doctrine was an extremely influential theory on the construction of the body. Although many of his contemporaries still relied on Hippocratic humoral doctrines, Bichat and his Parisian colleagues believed that medicine could only become a true science if physicians adopted the methods used in the other natural sciences. Scientific investigations would then transform general observations of complex phenomena into precise and distinct categories. In other words, physicians should link clinical studies of disease to systematic postmortem observations. Bichat's approach was inspired by the work of another French physician, Philippe Pinel (1755-1826), who argued that diseases must be understood in terms of the organic lesions found at autopsy, rather than explained away in terms of humoral pathology.
Bichat reasoned that organs that manifested similar traits in health or disease must share some common structural or functional components. Because this common element did not exist at the organ level, Bichat was convinced that there must be some common element at a deeper level, that is, at a finer level of resolution. Using various techniques to break up the organs, Bichat dissected out what he thought of as the fundamental elements of the body. Organs were teased apart by dissection, maceration, cooking, drying, and exposure to chemical agents such as acids, alkalis, and alcohol. Organs, therefore, were composed of a "web" of different elements, which Bichat referred to as "membranes" or "tissues."
According to Bichat, the human body was composed of some 21 different kinds of tissue, such as the nervous, vascular, connective, fibrous, and cellular tissues. Organs, which were aggregates of tissues, were also components of more complex systems, such as the respiratory, nervous, and digestive systems. The activities that characterized tissues were explained in terms of "irritability" (the ability to react to stimuli), "sensibility" (the ability to perceive stimuli), and "sympathy" (the mutual effect parts of the body exert on each other in sickness and health). Although Bichat could not resolve the tissues into more fundamental entities, he realized that they contained complex combinations of vessels and fibers. Thus, Bichat's tissue theory of general anatomy is quite different from the cell theory that was elaborated in the nineteenth century by Matthias Jacob Schleiden (1804-1881) and Theodor Schwann (1810-1882). Nevertheless, Bichat hoped that his analysis of the structure of the human body would lead to a better understanding of the specific lesions of disease and to improvements in therapeutic methods.
LOIS N. MAGNER