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LECTURE 6Physiological and physio pathologic views of medicine in the 17th and 18th century
Representative medical personalities of 17th and 18th century • The development of the microscopic anatomy
Physiological and physio pathologic views of medicine in the 17th and 18th century Representative medical personalities of 17th and 18th century • Called the "Age of Scientific Revolution", the seventeenth century represents a major turning point in the history of science. Instead of asking why things occur, scientists turned to how things happen. Experimentation developed and the language of science became mathematical. • latrochemistry, or medical chemistry, was the name given to the fusion of alchemy, medicine and chemistry that was practiced by the followers of Paracelsus.
Physiological and physio pathologic views of medicine in the 17th and 18th century • Jan Baptista van Helmont (1577-1644) was the leading iatrochemist of the seventeenth century. After taking a medical degree m 1599, van Helmont decided to take up a career of private research • Van Helmont advocated quantification and experiment, and his comparison of the weight of urine with that of water was the first measurement of its specific gravity. Another contribution was his recognition that air was composed of several gases. • Van Helmont was a founder of the concept of disease as a distinct entity existing parasitically in the body. This was in contradiction to the Galenic concept that disease was part of the person and represented a derangement of the humours. • Robert Boyle (1627-1691) was an important proponent of atomism. He demonstrated the necessity of air for life.
Physiological and physio pathologic views of medicine in the 17th and 18th century • He formulated the following law: the volume of a gas varies inversely with the pressure at a constant temperature. • William Harvey (1578-1657) proved the continuous circulation of the blood within a contained system. • He gained a wide reputation and even became a court physician to King James I and to King Charles I. • His greatest work was published at Frankfurt in 1628 Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus (Anatomical Treatise on the Movement of the Heart and Blood in Animals). • Harvey showed that because of the valves in the heart and the veins, blood could flow in only one direction. Seeing that both ventricles of the heart contracted and expanded together, he concluded that there was no pressure difference between them that could drive blood through the thick septum.
Physiological and physio pathologic views of medicine in the 17th and 18th century • By experiment of a live snake, he demonstrated the direction of flow toward the heart in the great vein (vena cava) and away from the heart in the main artery (aorta). • Georg Ernst Stahl (1660-1734). He rejected the view that the body was simply a machine and postulated instead the existence of an anima or sensitive soul that regulates the body health. Stahl was also a strong advocate of bloodletting. A colleague of Stahl’s at the University of Halle was: • Friederich Hoffmann (1660-1742). According to his theory the entire body was composed of fibres which could dilate or contract in response to a property called tonus. This in turn was controlled by a nervous ether emanating from the brain.
Physiological and physio pathologic views of medicine in the 17th and 18th century • Hermann Boerhaave (1668-1738). Under the influence of Hermann, the University of Leyden became the leading medical school of all Europe. He placed the greatest emphasis on bedside instruction and also insisted that the student follow a patient’s body to the • Leopold Auenbrugger (1722-1809). He invented the diagnosis by percussion of the chest. He also showed how to plot the outlines of the heart and lungs by percussion.He recognized diseased areas of lung, repeatedly confirming his options by postmortem examination. His book Inventum novum (1761) seems to be the first ever devoted entirely to diagnosis and the first to be based on an objective sign of disease. • Alexander Monro (1697-1767) was a Scottish anatomist who studied under Boerhaave at Leyden. He returned to Edinburgh and brought its medical school into the front rank.
Physiological and physio pathologic views of medicine in the 17th and 18th century • Albrecht von Haller (1708-1777) was the most notable of all Boerhaave’s disciples. His many contributions to anatomy included a correct explanation of hernia. As a physiologist he demonstrated that while irritability was a property of muscles’ fiber, sensibility was a characteristic of the nerve fiber. • John Hunter a Scottish surgeon studied, taught and practiced in London. He was also regarded as the founder of scientific geology. His many contributions to medical science included the first account of inflamation.
Physiological and physio pathologic views of medicine in the 17th and 18th century The development of the microscopic anatomy • One of the most important inventions in the development of medicine and general science was the microscope. • Marcello Malpighi (1628-1694) was regarded as the founder of biological microscopy. By developing techinques for preparing tissues to be examined under the microscope he was able to make observations otherwise impossible. • Antoni von Leeuwenhoek (1632- 1723) was a specialist of polishing the lens. Wanting to visualize the texture of the clothes, he included a biconvex lens into a metallic frame obtaining an augmentation to 270 times.
Physiological and physio pathologic views of medicine in the 17th and 18th century • Thus it were discovered the red globules, the structure of the knurled muscles, the structure of the crystalline. • He wrote a work Arcana naturae ope microscopium detecta (The Secrets of the Nature with the help of Microscope). • Jan Swammerdam (1637 – 1685) a Dutch doctor and biochemist. He studies the insects’ life and the human’s red globules. • He’s the first who uses the dissection under the microscope. His technique will be used during the next 100 years. • Robert Hooke (1635 – 1703), English astronomer and physician. He studied at Oxford and discovered in 1652 the cell opening the road to cytology.