Dr Theodor Schwann,cell theory, Slides of Physiology

Download Dr Theodor Schwann,cell theory and more Slides Physiology in PDF only on Docsity!

Theodore

Schwann

Dr.Priyadharshini.V Ist yr PG IPEM,MMC

Synopsis

• Back ground
• Early life
• Career^ • Personal life
  • Awards Discovery of Pepsin Vitalism and germ theory Fermentation Cell doctrine Histology Schwann cells Metabolism Other works

Early life

• (^) 1829- Medicine and Natural sciences at the University of Bonn, influenced by Johannes Müller.
• (^) 1831-Clinical training in Wurzburg.
• (^) 2 years later,moved to the University of Berlin where he rejoined Johannes Müller as his doctoral student.
• (^) Under the supervision of Muller, thesis on the necessary role of oxygen in the development of the chicken embryo

Career

• (^) 1834- Graduated and accepted Muller’s offer to work as his research assistant in Berlin.
• (^) 1848 - Professor of anatomy at the University of Liege, Belgium.
• (^) 1858 -Appointed to the chair of Physiology.

Vitalism and germ theory

• (^) In one experiment,broth of nutrients were sterilized by boiling and heated the air above high temperature. The result was no microbes grew and no biological or chemical activity were observed in the broth either. This experiment convinced Schwann that he had killed all the microbes and no more could be produced. The theory of SPONTANEOUS GENERATION was incorrect.
• (^) Pasteur germ theory and Lister antiseptic application were influenced by Schwann.

Fermentation

• (^) 1836-Identified the role of microorganisms in putrefaction and Alcohol fermentation. “conversion of sugar to alcohol during fermentation was a biological process that required the action of a living substance (yeast) rather than a chemical process of sugar oxidation.”
• (^) Acceptance only came with Louis Pasteur’s work over a decade later. Later wrote in a letter to Schwann: “For twenty years past I have been travelling along some of the paths opened up by you.”

Contd., Microscopical researches into the Accordance in the Structure and Growth of Animals and Plants.

• (^) Described the cellular structure of plants and animals and the development of adult cells. cell theory – that all living things are made of cells: all animal tissues are built up from a basic cell structure in the same way as plants are. He also noted that all animal cells contain a nucleus.

Contd.,

• (^) 1838-Presented about his evidence for the cell doctrine to the Academy in Paris.
• (^) The book appeared in German in 1839 and was translated into English by the Sydenham Society in 1847. The cause of nutrition and growth resides not in the organism as a whole, but in the separate elementary parts — the cells.”

Schwann cells

• (^) Studied peripheral nerve cells and described Membranous wrapping, produced by a specialized type of cell, envelops the prolongation of nerve cell associated with the supporting cell and this membranous sheath- Schwann cells.

METABOLISM

• (^) Phenomena of individual cells can be placed into two classes: " combination of the molecules to form a cell-plastic phenomena," and "those which result from chemical changes either in the component particles of the cell itself, or in the surrounding cytoblastema [the modern cytoplasm].- metabolic phenomena.
• (^) coined "METABOLISM," which became generally adopted for the sum total of chemical processes by which energy changes occur in living things.

First rebreather designed in 1853 in Belgium by professor T. Schwann Became more of an inventor, portable closed circuit respiratory apparatus allowing human life in an unbreathable environment. 1876-Demonstrated the system at the Health and Safety Exhibition in Brussels

BIG MISTAKE Big hit with cell-theory, however, his book also contained a significant error, because he did not recognize that new cells are formed by pre-existing cells. He wrote:

• (^) “A structureless substance is present which lies either around or in the interior of cells already existing; and cells are formed in it in accordance with certain laws” He called this non-existent structure less substance blastema.
• (^) In 1855 Rudolph Virchow published an essay in which he asserted that: “Every cell arises from another cell.” This was the beginning of the end for Schwann’s non-existent blastema.

Awards

• (^) 1845-Royal Society Copley Medal for his cell work
• (^) 1879- Elected to the Royal Society and also to the French Academy of Science.

This bronze statue of Theodor Schwann, who teached in the University of Liege from 1848 on, stands at the left of the entrance staircase to the Zoological Institute.