Georg Prochaska (sometimes also Juri, Jiří or Georgius Prochaska; ; 10 April 1749 – 17 July 1820) was a Czech-Austrian

anatomist Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

ophthalmologist Ophthalmology (, ) is the branch of medicine that deals with the diagnosis, treatment, and surgery of eye diseases and disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a ...

physiologist Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out chemical and ...

writer A writer is a person who uses written words in different writing styles, genres and techniques to communicate ideas, to inspire feelings and emotions, or to entertain. Writers may develop different forms of writing such as novels, short sto ...

and university professor. He lived in the

Holy Roman Empire The Holy Roman Empire, also known as the Holy Roman Empire of the German Nation after 1512, was a polity in Central and Western Europe, usually headed by the Holy Roman Emperor. It developed in the Early Middle Ages, and lasted for a millennium ...

and then in the

Austrian Empire The Austrian Empire, officially known as the Empire of Austria, was a Multinational state, multinational European Great Powers, great power from 1804 to 1867, created by proclamation out of the Habsburg monarchy, realms of the Habsburgs. Duri ...

. 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

Prochaska was born on 10 April 1749 in

Blížkovice Blížkovice () is a market town in Znojmo District in the South Moravian Region of the Czech Republic. It has about 1,200 inhabitants. Geography Blížkovice is located about northwest of Znojmo and southwest of Brno. It lies in the Jevišovice ...

. He studied medicine in

Prague Prague ( ; ) is the capital and List of cities and towns in the Czech Republic, largest city of the Czech Republic and the historical capital of Bohemia. Prague, located on the Vltava River, has a population of about 1.4 million, while its P ...

and

Vienna Vienna ( ; ; ) is the capital city, capital, List of largest cities in Austria, most populous city, and one of Federal states of Austria, nine federal states of Austria. It is Austria's primate city, with just over two million inhabitants. ...

, and from 1778 until 1791 was a professor of

anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

physiology Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ syst ...

and

ophthalmology Ophthalmology (, ) is the branch of medicine that deals with the diagnosis, treatment, and surgery of eye diseases and disorders. An ophthalmologist is a physician who undergoes subspecialty training in medical and surgical eye care. Following a ...

at the University of Prague. In 1791 he succeeded Joseph Barth as professor of anatomy and ophthalmology at the

University of Vienna The University of Vienna (, ) is a public university, public research university in Vienna, Austria. Founded by Rudolf IV, Duke of Austria, Duke Rudolph IV in 1365, it is the oldest university in the German-speaking world and among the largest ...

. He died on 17 July 1820 in Vienna.

Discoveries

Prochaska was a pioneer in the field of

neurophysiology Neurophysiology is a branch of physiology and neuroscience concerned with the functions of the nervous system and their mechanisms. The term ''neurophysiology'' originates from the Greek word ''νεῦρον'' ("nerve") and ''physiology'' (whic ...

, 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 nerve A motor nerve, or efferent nerve, is a nerve that contains exclusively efferent nerve fibers and transmits motor signals from the central nervous system (CNS) to the effector organs (muscles and glands), as opposed to sensory nerves, which transf ...

s. Prochaska used the term ''vis nervosa'' as a direct

analogy Analogy is a comparison or correspondence between two things (or two groups of things) because of a third element that they are considered to share. In logic, it is an inference or an argument from one particular to another particular, as oppose ...

Isaac Newton Sir Isaac Newton () was an English polymath active as a mathematician, physicist, astronomer, alchemist, theologian, and author. Newton was a key figure in the Scientific Revolution and the Age of Enlightenment, Enlightenment that followed ...

'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 (), also known as gravitation or a gravitational interaction, is a fundamental interaction, a mutual attraction between all massive particles. On Earth, gravity takes a slightly different meaning: the observed force b ...

), but at the same time were unexplainable. Prochaska described the "sensorium commune" as the core mechanism of the reflex. It involved the

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal c ...

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 The basal ganglia (BG) or basal nuclei are a group of subcortical Nucleus (neuroanatomy), nuclei found in the brains of vertebrates. In humans and other primates, differences exist, primarily in the division of the globus pallidus into externa ...

, and had the ability to reflect sensory impressions into the motor nervous system by definite laws unique to itself, and also independent of

consciousness Consciousness, at its simplest, is awareness of a state or object, either internal to oneself or in one's external environment. However, its nature has led to millennia of analyses, explanations, and debate among philosophers, scientists, an ...

. Prochaska demonstrated that reflex worked without a

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

, 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

External links

on quido.cz (in Czech) {{DEFAULTSORT:Prochaska, Georg 1749 births 1820 deaths Scientists from the Austrian Empire 18th-century Austrian biologists Austrian physiologists Czech physiologists Czech anatomists People from Znojmo District Academic staff of Charles University Academic staff of the University of Vienna

Life

Discoveries

References

Further reading

External links