Joseph von Gerlach (3 April 1820 – 17 December 1896) was a German professor of

anatomy Anatomy () is the branch of biology concerned with the study of the 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 science, having its ...

at the

University of Erlangen A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, th ...

. He was a native of

Mainz Mainz () is the capital and largest city of Rhineland-Palatinate, Germany. Mainz is on the left bank of the Rhine, opposite to the place that the Main (river), Main joins the Rhine. Downstream of the confluence, the Rhine flows to the north-we ...

Rhineland-Palatinate Rhineland-Palatinate ( , ; german: link=no, Rheinland-Pfalz ; lb, Rheinland-Pfalz ; pfl, Rhoilond-Palz) is a western state of Germany. It covers and has about 4.05 million residents. It is the ninth largest and sixth most populous of the ...

. Gerlach was a pioneer of

histological staining Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Stains and dyes are frequently used in histology (microscopic study of biological tissues), in cytology (microscopic study of cells), and in the m ...

and anatomical

micrography Micrography (from Greek, literally small-writing – "Μικρογραφία"), also called microcalligraphy, is a Jewish form of calligrams developed in the 9th century, with parallels in Christianity and Islam,carmine Carmine ()also called cochineal (when it is extracted from the cochineal insect), cochineal extract, crimson lake, or carmine lake is a pigment of a bright-red color obtained from the aluminium complex derived from carminic acid. Specific code n ...

mixed with

gelatin Gelatin or gelatine (from la, gelatus meaning "stiff" or "frozen") is a translucent, colorless, flavorless food ingredient, commonly derived from collagen taken from animal body parts. It is brittle when dry and rubbery when moist. It may also ...

as a

histological stain Staining is a technique used to enhance contrast in samples, generally at the microscopic level. Stains and dyes are frequently used in histology (microscopic study of biological tissues), in cytology (microscopic study of cells), and in the ...

. Along with

Camillo Golgi Camillo Golgi (; 7 July 184321 January 1926) was an Italian biologist and pathologist known for his works on the central nervous system. He studied medicine at the University of Pavia (where he later spent most of his professional career) betwee ...

, he was a major proponent of the

reticular theory Reticular theory is an obsolete scientific theory in neurobiology that stated that everything in the nervous system, such as brain, is a single continuous network. The concept was postulated by a German anatomist Joseph von Gerlach in 1871, and was ...

that the brain's

nervous system In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes th ...

consisted of processes of contiguous cells fused to create a massive meshed network. Gerlach summed up his theory by stating:

the finest divisions of the protoplasmic processes ultimately take part in the formation of the fine nerve fibre network which I consider to be an essential constituent of the gray matter of the spinal cord. The divisions are none other than the beginnings of this nerve fibre net. The cells of the gray matter are therefore doubly connected by means the nerve process which becomes the axis fibre and through the finest branches of the protoplasmic processes which become a part of the fine nerve fibre net of the gray matter.

The reticular theory predominated until the 1890s when Ramon y Cajal brought forth his

neuron doctrine The neuron doctrine is the concept that the nervous system is made up of discrete individual cells, a discovery due to decisive neuro-anatomical work of Santiago Ramón y Cajal and later presented by, among others, H. Waldeyer-Hartz. The term ''n ...

of synaptic junctions, which in essence replaced the reticular theory. Gerlach was one of the first physicians to use

photomicrography A micrograph or photomicrograph is a photograph or digital image taken through a microscope or similar device to show a magnified image of an object. This is opposed to a macrograph or photomacrograph, an image which is also taken on a mi ...

for medical research. In 1863 he published a handbook titled ''Die Photographie als Hilfsmittel mikroskopischer Forschung'' (Engl. "Photography as a tool in microscopic science") in which he discusses the practical and technological aspects of microscopic photography. The eponymous "Gerlach's valve" (''valvula processus vermiformis'') is named after him. This anatomical structure is a fold of membrane sometimes found at the opening of the

vermiform appendix The appendix (or vermiform appendix; also cecal r caecalappendix; vermix; or vermiform process) is a finger-like, blind-ended tube connected to the cecum, from which it develops in the embryo. The cecum is a pouch-like structure of the large i ...

. In his article ''Ueber das Hautathmen''von Gerlach, J. (1851): ''Ueber das Hautathmen''. In: ''Archiv für Anatomie, Physiologie und wissenschaftliche Medicin''. pp. 431–455 (Engl. "On skin respiration") he was the first to show that human skin uses oxygen from ambient air.

References

Neurophilosophy.wordpress
On discovery of the neuron * This article incorporates information based on a translation of an equivalent article at the

German Wikipedia The German Wikipedia (german: Deutschsprachige Wikipedia) is the German-language edition of Wikipedia, a free and publicly editable online encyclopedia. Founded on March 16, 2001, it is the second-oldest Wikipedia (after the English Wikipedia), ...

External links

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Laboratory Manual of Human Anatomy
1820 births 1896 deaths German anatomists Physicians from Mainz University of Erlangen-Nuremberg faculty German histologists People from Rhenish Hesse {{Germany-academic-bio-stub