THE PANCREAS
The pancreas is both an endocrine gland that produces hormones and an exocrine gland that produces digestive enzymes. It is, therefore, responsible for much metabolism within the body. A major disorder of the endocrine pancreas is diabetes mellitus.
The pancreas is located behind the stomach, between the spleen and the duodenum.
Human Anatomy
Picture of the Pancreas
It houses the islets of Langerhans, which secrete glucagon and insulin, hormones that help to regulate much of the carbohydrate, fat, and protein metabolism within the body. The islets of Langerhans have three types of hormone-secreting cells: alpha, beta, and delta cells. It also has F cells, which secrete pancreatic polypeptide.
Somatostatin is produced by delta cells of the pancreas. It is a hormone essential in carbohydrate, fat, and protein metabolism (i.e., homeostasis of ingested nutrients). Little is known about pancreatic somatostatin, but it is probably involved in the regulation of alpha-cell and beta-cell function within the islets. Presumably, somatostatin inhibits both glucagon and insulin secretion. Pancreatic somatostatin is different from hypothalmic somatostatin, which inhibits the release of growth hormone.
The beta cells secrete insulin. Insulin is an anabolic hormone that promotes the synthesis of proteins, carbohydrates, lipids, and nucleic acids. The major sites of insulin-promoted synthesis are the liver, muscle, and adipose tissue. The net effect of insulin in these tissues is to stimulate cellular metabolism. Overall, however, the major consequence of insulin release is to decrease blood glucose. Insulin also facilitates the intracellular transport of potassium.
Glucagon is produced by the alpha cells of the pancreas and by a number of cells lining the gastrointestinal tract. Glucagon acts primarily in the liver. It acts as an antagonist to insulin.
Pathophysiology The Biologic Basis for Disease in Adults and Children 1990.
Questions or comments are welcomed.
You can also visit Oma at http://omaswisdom.blogspot.com, http://omaslife.blogspot.com, http://omaspolitics.blogspot.com, and http://tbcspeaks.blogspot.com. Just click the name of the site you want to visit.
