Born: 18 December 1787 Libochovice, Bohemia, Austrian Monarchy
Died: 28 July 1869 (aged 81) Prague, Austria-Hungary
Jan Evangelista Parkyn (17 or 18 December 1787 – 28 July 1869), also known as Johann Evangelista Purkinje, was a Czech anatomist and physiologist. He developed the name protoplasm for a cell’s fluid material in 1839. He was a well-known scientist during his time. His fame was such that when people from outside Europe wrote him letters, all they had to write was “Parkyn, Europe” as the address.
Parkyn was born in the Bohemian Kingdom (then part of the Austrian monarchy, now the Czech Republic). Parkyn entered the Piarists order as a monk after graduating from high school in 1804, but later departed “to engage more freely with science.” He received a degree in medicine from Charles University in Prague in 1818 and was appointed a Professor of Physiology. He discovered the Purkinje effect, which describes how the human eye is far less sensitive to dim red light than to faint blue light, and described various entoptic phenomena in 1823. He contributed to the development of experimental psychology by publishing two volumes, Observations and Experiments Investigating the Physiology of Senses and New Subjective Reports about Vision.
In 1839, he established the world’s first Department of Physiology and the world’s second formal physiology laboratory at the University of Breslau in Prussia (now Wroclaw, Poland). He was a founding member of the Literary-Slav Society in this city.
He took the chair of physiology at Prague Medical Faculty in 1850, a position he held until his death. Purkinje cells, huge neurons with multiple branching dendrites located in the cerebellum, were discovered by him in 1837. Purkinje fibers, the fibrous tissue that transports electrical impulses from the atrioventricular node to all sections of the heart’s ventricles, was discovered by him in 1839.
Purkinje images, or reflections of objects from eye structures, and the Purkinje shift, or the change in the brightness of red and blue colors as light intensity declines gradually after dusk, are two more discoveries. Parkyn also coined the words plasma (for the component of blood left after suspended cells have been removed) and protoplasm (for the component of blood left after suspended cells have been removed) (the substance found inside cells.)
Parkyn was one of the first to utilize a microtome to slice tissue into thin slices for microscopic study, as well as one of the first to use an enhanced compound microscope. In 1829, he published a paper on the effects of camphor, opium, belladonna, and turpentine on people.
He also tried nutmeg that year, “washing down three ground nutmegs with a glass of wine and experiencing headaches, nausea, euphoria, and hallucinations that lasted several days,” which is still a reasonable description of today’s typical nutmeg binge. Parkyn discovered sweat glands in 1833 and submitted a thesis in 1823 that identified nine major fingerprint configuration groupings. Parkyn was also the first to describe and display neuromelanin, an intracytoplasmic pigment in the substantia nigra, in 1838.
Parkyn also recognized the significance of Eadweard Muybridge’s work. Parkyn created his stroboscope, which he called forolyt. He put nine images of himself on the disc, shot from various angles, and entertained his grandchildren by showing them how he, an elderly and well-known professor, spins about at great speed.
Parkyn examined the development of avian eggs in the bodies of female chickens before they laid the eggs between 1825 and 1832. He isolated the germinal vesicle, which was ultimately identified as the fertilized egg’s nucleus. Before his discovery, scientists debated whether the embryo began in the egg or elsewhere. Some speculated that the embryo was formed in the egg white, yolk, or white ovalbumin component known as chalazae.
Parkyn examined female germ cells that he had extracted from chicken ovaries that he had dissected after obtaining an achromatic microscope, which eliminates the colored fringes that appear around things viewed under the microscope. He noticed a white elevation on the yolk’s surface and used a needle to pull it apart, revealing the vesicle, or nucleus. Based on his findings, he concluded that the vesicle must be an egg cell, which he named the germinal vesicle, from which the embryo develops. The ovum or egg cell, perky suggested forms around the vesicle. Parkyn also proposed that the vesicle, while present in immature eggs, disappears after fertilization.
In his article Symbolae ad ovi avium historiam ante incubation (Contributions to the history of birds’ ova before incubation), published in 1825, he reported his findings.
Purkyn’s work had an impact on other scientists. He corresponded with Ernst Karl von Baer in Künigsberg, Germany, about his studies, which led to the discovery of egg cells in animals. Purkyn’s findings, together with his discovery of granule-like cellular structures in animal and plant tissues, aided in the development of cell theory. Parkyn coined the term protoplasm to describe the substance that forms first in the development of an animal or plant cell to characterize the contents of cells.
Furthermore, in the 1830s, Theodor Schwann of Berlin, Germany, developed the concept of cellular structure based on these observations.
Parkyn researched various occurrences from 1829 until 1845. In 1829, he documented the experimental effects of camphor, opium, belladonna, and turpentine on people and researched the digitalis toxicity on himself, introducing the notion of physiological pharmacology. During the mid-nineteenth century, his phonetic studies inspired the work of Johann Nepomuk Czermak in Breslau, Prussia, and Ernst Wilhelm von Brücke in Berlin, Germany, through observations on himself.
Parkyn maintained that physiology should be an experimental science, as opposed to what he called the theoretical approaches of physiology practiced by many researchers in central Europe. In 1839, he established one of the first physiology departments at the University of Breslau, and in 1839, he established one of the first independent physiological laboratories in Breslau, afterward known as the Physiological Institute.
Parkyn studied many-body aspects with microscopes. In the 1830s, Parkyn and his student Gabriel Valentine at the University of Breslau characterized ciliary motion in what they called higher animals, as well as its independence from nervous system control.
In 1835, they published an essay on the ciliary motion. Hair-like organelles coat the surfaces of some cells and beat in rhythmic waves to transfer things along the tissue provide ciliary motion in tissues. Parkyn described the branched nerve cells in the brains of sheep, calf, pig, horse, and human beings in 1837, and the fibers that form a network in the hearts of the same animals in 1839. He looked at the number and distribution of nerve fibers in the roots of both spinal and cerebral nerves in organisms from various animal species, based on their diameters. He hypothesized that thick and thin fibers had different roles.
Family and Death
In 1827, at the age of 40, he married Julia Agnes Rudolphi (1800–1835), the daughter of his supporter, Karl Asmund Rudolphi (1771–1832), a Swedish-born natural scientist. They have two sons and two daughters. In Wroclaw, his wife and daughters died of cholera, leaving him with two boys. Emanuel Purkyn [cs] (1831–1882), the older son, became a naturalist, while Karel (1834–1868) became a painter. In the modern-day Czech Republic, he is buried in the Prague Vyehrad National Cemetery in Vyehrad, Prague.
From 1960 to 1990, Masaryk University in Brno, Czech Republic, and a separate military medical institution in Hradec Králové (1994–2004) shared his name. Jan Evangelista Purkyn University in st nad Labem (Univerzita Jana Evangelisty Purkyn v st nad Labem) in st nad Labem (Univerzita Jana Evangelisty Purkyn v st nad Labem) in st nad Labem (Univerzita Jana Evangelis Parkyn crater on the Moon and asteroid 3701 Purkyn are also named after him.
Purkinje highlighted the importance of microscopy, particularly the new achromatic microscopes, and created various novel teaching instruments, including a knife that predated the microtome. He also pioneered the use of balsam-sealed preparations and modified Louis J.M. Daguerre’s techniques to create the first photos of microscopic materials.
Purkinje studied the skin of various animals, ciliary motion, nerve cells, myelinated nerve fibers, the large flask-shaped cells with numerous dendrites in the cerebellar cortex (now known as Purkinje cells), the unusual muscle fibers found below the endocardium in a specific region of the ventricles of the heart (the Purkinje fibers), and the unusual muscle fibers found below the endocardium in a specific region of the ventricles of the He was made a Foreign Member of the Royal Society in 1850.
Purkinje’s eponym has been assigned to many of his discoveries [Purkinje cells in the cerebellum, Purkinje cardiac fibers, Purkinje bone corpuscles, Purkinje granular layers (branched spaces in tooth enamel), Purkinje-Sanson images in the pupil, Purkinje tree (shadows of retinal vessels), Purkinje phenomenon, and the Purkinje axis-cylinder in nerve as attested by his eponym Purkinje’s groundbreaking contributions to the biological sciences have been recognized by the biological research community, demonstrating their lasting value.