LECTURE 6
Physiological 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
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Physiological and physio pathologic views of medicine in the 17th and 18th century
Representative medical personalities of 17th
and 18th century
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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
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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
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He formulated the following law: the volume of a gas varies inversely with the
pressure at a constant temperature.
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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.
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Physiological and physio pathologic views of medicine in the 17th and 18th century
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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).
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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.
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Physiological and physio pathologic views of medicine in the 17th and 18th century
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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
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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
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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
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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.