Theodor Schwann, German cell biologist and physiologist, was born on december 7th in 1810 in Neuss (D).

Schwann studied medicine at the University of Berlin under Johannes Muller, a brilliant university teacher, teaching many German physiologist of the 19th Century.

1836, still at the university in Berlin, he discovered in the gastric juice pepsin, a digestive enzyme for protein. It was the first enzyme that could be presented from an animal tissue.

Schwann 1837 also showed that something in the air but they do not (even), which could be destroyed by heat, rot caused.

1838 Schwann become a professor at the Belgian University of Leeuven, 1848 he was appointed to the University of Liege.

During this time he discovered that sugar and starch fermentation are not purely chemical, but life processes. He examined the muscle contraction and the structure of nerve cell. He discovered the striated muscles in the upper esophagus and the myelin sheath of peripheral nerves, which we still call him in honor of Schwann cells.

Schwann coined the term "metabolism" to describe chemical changes that are observed in living tissue. Next, he formulated from observations of eggs, the basic principle of embryology that egg cells are single cells that develop into complex organisms.

Schwann developed in 1839 together with Matthias Schleiden and the cell theory, which identifies the cells as the basic particles of plants and animals. Schwann and Schleiden recognized that some organisms are unicellular, while others are multicellular. They also recognized that include membranes and nuclei of the general cell properties and described it by comparison of the various animal and plant tissues. These observations and the Schwann cell theory were summarized in "Microscopic Investigations on the Accordance in the Structure and Growth of Animals and Plants" and in 1839 published.

Schwann cells stimulated by his theory, the research in this area. Today he is considered the founder of modern histology. Theodor Schwann, died at the age of 71 years.