Theory celular

Theory celular

Robert Hooke, who had observed already in the seventeenth century that cork and other plant material was composed of cells (literally, cells) .. Anton van Leeuwenhoek (1632-1723),using simple microscopes, many observations made by laying the foundations of the microscopic morphology. In the late eighteenth century, Bichat gives the first definition of tissue (a set of cellswith similar form and function). Later in 1819, Meyer was given the name of Histology Bichat a book titled "Anatomy General · Applied to Physiology and Medicine. Two German scientists, Theodor Schwann,histologist and physiologist, and Jakob Schleiden, a botanist, noticed some fundamental community in the microscopic structure of plants and animals, in particular the presence of nuclei, the Britishbotanist Robert Brown was described recently (1827 .) Research published microscopic work together on the compliance of the structure and growth of plants and animals (Microscopische Untersuchungenüber die Übereinstimmung in der Struktur und dem Wachstum der Tiere und Pflanzen, Berlin, 1839). Settled the first principle of the cell theory of history: "Everything in living is made up of cells orproducts secreted by the cells." Another German physician Rudolf Virchow, interested in the cellular specificity of the disease (only certain kinds of cells appear to be involved in each disease),explained what we consider the second principle: "Every cell has originated from another cell, this division. "

We are now able to add that the division is by bipartition, because despite appearances,the division is always in the background, binary. The Virchow first popularized it in the form of an aphorism created by François Vincent Raspail, "omnis cellula e cellula." Virchow ended downspeculation that made a hypothetical cell blastema. Its premise, which implies the continuity of the cell lines, is the origin of the observation by August Weismann in the existence of a germ line, through...