Georg Prochaska; (first name sometimes referred to as Juri, Jiří or Georgius) was a leading Czech

Czech Republic

The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....

 or Austrian anatomist, ophthalmologist, physiologist, writer

Writer

A writer is a person who produces literature, such as novels, short stories, plays, screenplays, poetry, or other literary art. Skilled writers are able to use language to portray ideas and images....

 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

Prague

Prague is the capital and largest city of the Czech Republic. Situated in the north-west of the country on the Vltava river, the city is home to about 1.3 million people, while its metropolitan area is estimated to have a population of over 2.3 million...

 and Vienna

Vienna

Vienna is the capital and largest city of the Republic of Austria and one of the nine states of Austria. Vienna is Austria's primary city, with a population of about 1.723 million , and is by far the largest city in Austria, as well as its cultural, economic, and political centre...

, and from 1778 until 1791 was a professor of anatomy

Anatomy

Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...

, physiology

Physiology

Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...

 and ophthalmology

Ophthalmology

Ophthalmology is the branch of medicine that deals with the anatomy, physiology and diseases of the eye. An ophthalmologist is a specialist in medical and surgical eye problems...

 at the University of Prague

Charles University in Prague

Charles University in Prague is the oldest and largest university in the Czech Republic. Founded in 1348, it was the first university in Central Europe and is also considered the earliest German university...

. In 1791 he succeeded Joseph Barth

Joseph Barth

Joseph Barth October 28, 1746, Valletta, Malta - April 7, 1818, Vienna, Austria, was a notable 18th century ophthalmologist.-Education:Anatomical & Surgical School at Sacra Infermeria, Valletta , Santo Spirito Hospital in Rome , University of Vienna...

 as professor of anatomy and ophthalmology at the University of Vienna

University of Vienna

The University of Vienna is a public university located in Vienna, Austria. It was founded by Duke Rudolph IV in 1365 and is the oldest university in the German-speaking world...

.

Discoveries

Prochaska was a pioneer in the field of neurophysiology

Neurophysiology

Neurophysiology is a part of physiology. Neurophysiology is the study of nervous system function...

, and is 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 and motor nerves.

Prochaska used the term "vis nervosa" as a direct analogy

Analogy

Analogy is a cognitive process of transferring information or meaning from a particular subject to another particular subject , and a linguistic expression corresponding to such a process...

 to Isaac Newton

Isaac Newton

Sir Isaac Newton PRS was an English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian, who has been "considered by many to be the greatest and most influential scientist who ever lived."...

's "vis gravitans", because he believed that "vis nervosa" was an elemental form of energy, which could not be observed except through its effects such as reflexes and reflections, and adhered to natural laws that could be described (as could Newton's theories of gravitation

Gravitation

Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped...

), but at the same time were unexplainable.

Prochaska described the "sensorium commune" as the core mechanism of the reflex. It involved the spinal cord

Spinal cord

The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...

, medulla oblongata

Medulla oblongata

The medulla oblongata is the lower half of the brainstem. In discussions of neurology and similar contexts where no ambiguity will result, it is often referred to as simply the medulla...

 and the basal ganglia

Basal ganglia

The basal ganglia are a group of nuclei of varied origin in the brains of vertebrates that act as a cohesive functional unit. They are situated at the base of the forebrain and are strongly connected with the cerebral cortex, thalamus and other brain areas...

, and had the abililty 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

Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

, 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, which 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 (physiologist)

Thomas Laycock was an English neurophysiologist who was a native of York.Among medical historians, he is best known for his influence on the young John Hughlings Jackson and the psychiatrist James Crichton-Browne....

(1812–1876).

External links

• (in Czech) http://www.quido.cz/osobnosti/prochaska.htm - another image of Jiří Procháska