- Hormones are organic substance secreted by plants and animals that functions in the regulation of physiological activities and in maintaining homeostasis.
- Hormones carry out their functions by evoking responses from specific organs or tissues that are adapted to react to minute quantities of them.
- Insulin is a hormone that regulates the level of sugar (glucose) in the blood and is produced in the pancreas.
- Insulin is secreted when the level of blood glucose rises after a meal.
- When the level of blood glucose falls, secretion of insulin stops, and the liver releases glucose into the blood.
- Inadequate production of insulin is responsible for the condition called diabetes mellitus.
- Severe diabetics require periodic injections of insulin, which is extracted from the pancreas of pigs, sheep, and oxen.