World of Anatomy and Physiology on Jan Evangelista Purkinje (Purkyne)
Jan Evangelista Pukinje is credited with articulating a physiological phenomenon (now known as the Purkinje effect) that involves changes in visual perception. Specifically as the intensity of light decreases individuals perceive that red colored objects red objects fade faster than blue objects of equal brightness.
As a boy growing up in Bohemia (now part of the Czech Republic), Jan Purkinje showed great promise. His father, an estate manager who encouraged his son's interests, died when Purkinje was six years old. At the age of ten, Purkinje, an only child, was admitted to a Piarist monastery (established in 1597 to educate the poor) near the Austrian border. Purkinje became a choirboy and outstanding student at the monastery, quietly studying for the priesthood. Just before he was to be ordained a priest, Purkinje decided to take up the study of philosophy at Prague University. While there, he became interested in medicine. His research and tutoring during this time strengthened his physics and optics background.
In 1818, Purkinje presented his graduate thesis which described a visual phenomena now known as the Purkinje effect. He stated that as the intensity of light decreases, different colored objects that appeared to be the same brightness in highly intense light, appear to be unequally bright. In other words, as light intensity decreases, blue objects might appear to be brighter than red objects--even though they appeared to be the same brightness in the more intense light.
After graduating in 1819, Purkinje developed wide-ranging interests in the areas of experimental pharmacology and psychology, phonetics, histology, embryology, and physical anthropology. In 1823, the same year he took the position of Professor of Physiology and Pathology at the University of Breslau (now the Wroclaw province in Poland), Purkinje published another paper that recognized fingerprints as a way to identify individuals. He noted that fingerprints seemed to follow nine general patterns, he mentioned the ridge formations of the human palm.
In 1832, after obtaining a modern microscope, Purkinje began a new period of research. He found different ways to examine tissues under the microscope--fixing, sectioning, and staining. With his techniques, he saw structures that other observers hadn't noticed. For example, in 1837, Purkinje discovered large pear-shaped nerve cells in the outer layer of the brain that had several branches. These are now called Purkinje cells. He was the first to describe these cells as formations in the central nervous system of vertebrates and pointed out that they play an important role in nervous activity.
Two years later, as Purkinje was investigating the function of muscular organs, he discovered Purkinje fibers--special muscle fibers in the ventricles of the heart. Later it would be shown that Purkinje fibers have an important function; they conduct contraction signals to all parts of the heart.
That same year, Purkinje (no doubt influenced by his theological background) described the contents of animal embryos using the term protoplasm in its scientific sense. To him, the term meant "first formed," but eventually it took on a more general meaning: the living material inside a cell. Purkinje also conducted comparative studies of animal and plant tissue, observing that "granules"--now termed cells--were present in both. These observations laid the groundwork for Matthias Schleiden and Theodor Schwann who formulated their cell theory in 1839. Purkinje went on to open an independent physiological institute in Breslau--the first of its kind. Although such an institute was very rare until the mid-nineteenth century, it eventually become a regular department of medical schools.
After 1850, Purkinje returned to Prague. He devoted the remainder of his life to the cause of Czech nationalism and making science more accessible to his countrymen.
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