Georg Prochaska (sometimes also Juri, Jiří or Georgius Prochaska; cs, Jiří Procháska) (10 April 1749 in
Blížkovice – 17 July 1820 in
Vienna) was a leading Czech-Austrian
anatomist,
ophthalmologist
Ophthalmology ( ) is a surgery, surgical subspecialty within medicine that deals with the diagnosis and treatment of eye disorders.
An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Followin ...
,
physiologist
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical a ...
,
writer and university professor. He wrote the first genuine textbook on physiology and created the concept of nerve conduction among other theories. He was a staunch promoter of the modern reflex theory.
Life
He studied medicine in
Prague and
Vienna, and from 1778 until 1791 was a professor of
anatomy,
physiology and
ophthalmology at the
University of Prague. In 1791 he succeeded
Joseph Barth
Joseph Barth (28 October 1746 – 7 April 1818) was a Maltese-born Austrian ophthalmologist. He is believed to have been the first professor of ophthalmology.
Education
He studied at the Anatomical and Surgical School at Sacra Infermeria in V ...
as professor of anatomy and ophthalmology at the
University of Vienna.
Discoveries
Prochaska was a pioneer in the field of
neurophysiology, being remembered for developing a comprehensive theory of reflex action involving the concepts of "vis nervosa" and "sensorium commune". "Vis nervosa" was described as a latent nervous force possessed in the nerves, and the term ''sensorium commune'' was defined as the point of reflection between the
sensory
Sensory may refer to:
Biology
* Sensory ecology, how organisms obtain information about their environment
* Sensory neuron, nerve cell responsible for transmitting information about external stimuli
* Sensory perception, the process of acquiri ...
and
motor nerves.
Prochaska used the term ''vis nervosa'' as a direct
analogy
Analogy (from Greek ''analogia'', "proportion", from ''ana-'' "upon, according to" lso "against", "anew"+ ''logos'' "ratio" lso "word, speech, reckoning" is a cognitive process of transferring information or meaning from a particular subject ( ...
to
Isaac Newton's "vis gravitans", due to his belief that "vis nervosa" was an elemental form of energy, that could not be observed except through its effects such as reflexes and reflections, adhering to natural laws that could be described (as could Newton's theories of
gravitation
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stron ...
), but at the same time were unexplainable.
Prochaska described the "sensorium commune" as the core mechanism of the reflex. It involved the
spinal cord,
medulla oblongata
The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involun ...
and the
basal ganglia, and had the ability to reflect sensory impressions into the motor nervous system by definite laws unique to itself, and also independent of
consciousness. Prochaska demonstrated that reflex worked without a
brain, but could not work without a spinal cord, and summarized that voluntary behavior was a brain function, while reflex was spinal-based.
One of Prochaska's better-known writings is ''Dissertation on the Functions of the Nervous System'', a work that was later combined with John Augustus Unzer's ''The Principles of Physiology'' as one publication, being translated and edited by English physiologist
Thomas Laycock
Thomas Laycock (1786 – 7 November 1823) was an English soldier, explorer, and later businessman, who served in North America during the War of 1812, but is most famous for being the first European to travel overland through the interior of Ta ...
(1812–1876).
References
Further reading
Waves, Pulses, and the Theory of Neural Masses* Jiří Procházka: Georg Prochaska /1749-1820/, Genealogie, Brno 2013, .
External links
on quido.cz (in Czech)
{{DEFAULTSORT:Prochaska, Georg
Austrian physiologists
Czech physiologists
Czech anatomists
1749 births
1820 deaths
People from Znojmo District
Academic staff of Charles University
Academic staff of the University of Vienna