Theodor SchwannBorn 7 Dec 1810; died 11 Jan 1882 at age 71. German physiologist who founded modern histology by defining the cell in Mikroskopische Untersuchungen (1839) as the basic unit of animal structure that makes elementary parts (such as teeth, bone, muscle, cartilage, nerve tissue) by cell differentiation. This laid the foundations for the cell theory. Schwann also worked on fermentation and discovered the enzyme pepsin. Schwann cells are named after him. He also investigated muscular contraction and nerve structure; discovered the striated muscle in the upper esophagus and the Schwann sheath; identified the role of microorganisms in putrefaction; formulated basic principles of embryology (that the egg is a single cell that develops into a complete organism); and coined the term metabolism. |
