Explain how coordination takes place without nerves by the story of insulin.
A. In 1868 Paul Langerhans, professor of pathology at the university of Freburg in Germany, working on the structure of the pancreas, noted certain patches of cells quite different in appearance from the normal tissue cells of the organ and richly cupplied with blood vessels. They are known Islets of Langerhans, but their function remained unknown.
When pancreas is removed from the body of experimental animal, it was found that the animal developed a wellknown human ailment ‘sugar diabetes’. It is a cause in man was unknown, but evidence pointed to the pancreas as a possible role.
The animal treated with pancreatic Langerhans would not develop diabetes. This was really a strong evidence that the level of blood sugar is linked with the islet cells. The chemical substance secreted by these cells is the hormone insulin.
We can understand that the coordination also can be brought by the hormones, which are directly liberated into the blood.
Insulin is now produced in large quantities for the treatment of human sufferers from sugar diabetes, to whom it is administered by injection into the skin.