A porcine islet of Langerhans. The left image is a brightfield image created using hematoxylin stain; nuclei are dark circles and the acinar pancreatic tissue is darker than the islet tissue. The right image is the same section stained by immunofluorescence against insulin, indicating beta cells.
The endocrine (i.e., hormone-producing) cells of the pancreas are grouped in the islets of Langerhans. Discovered in 1869 by the German pathological anatomist Paul Langerhans, the islets of Langerhans constitute approximately 1 to 2% of the mass of the pancreas. There are about one million islets in a healthy adult human pancreas, which are interspersed evenly throughout the organ, and their combined weight is 1 to 1.5 grams. Each islet contains approximately one thousand cells and is 50-500 μm in diameter. Haematoxylin is extracted from the wood of the logwood tree. ... Beta cells are a type of cell in the pancreas in areas called the islets of Langerhans. ... The endocrine system is a control system of ductless endocrine glands that secrete chemical messengers called hormones that circulate within the body via the bloodstream to affect distant organs. ... A hormone (from Greek horman - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ... The pancreas is an organ that serves two functions: exocrine - it produces pancreatic juice containing digestive enzymes. ... 1869 (MDCCCLXIX) is a common year starting on Friday (link will take you to calendar) of the Gregorian calendar or a common year starting on Sunday of the 12-day-slower Julian calendar. ... Paul Langerhans (1847 - 1888) was a famous German pathologist and biologist. ... A micrometre (American spelling: micrometer), symbol µm, is an SI unit of length. ...
Hormones produced in the Islets of Langerhans are secreted directly into the blood flow by (at least) four different types of cells:
Islets can influence each other through paracrine and autocrine communication, and beta-cells are coupled electrically to beta-cells (but not to other cell-types). The structure of insulin. ... Beta cells are a type of cell in the pancreas in areas called the islets of Langerhans. ... Glucagon ball and stick model Glucagon is a 29-amino acid polypeptide acting as an important hormone in carbohydrate metabolism. ... Alpha cells are endocrine cells in the islets of Langerhans of the pancreas. ... Somatostatin is a hormone. ... Delta cells are somatostatin producing cells. ... Peptides are the family of molecules formed from the linking, in a defined order, of various amino acids. ... PP cells are pancreatic polypeptide producing cells in the islets of Langerhans in the pancreas. ... Paracrine signalling is a form of signalling in which the target cell is close to the signal releasing cell, and the signal chemical is broken down too quickly to be carried to other parts of the body. ... Autocrine signalling is a form of signalling in which the target cell is the secretory cell itself. ...
The paracrine feedback system of the islets of Langerhans has the following structure:
Insulin: Activates beta cells and inhibits alpha cells.
Glucagon: Activates beta cells and delta cells.
Somatostatin: Inhibits alpha cells and beta cells.
Electrical activity of pancreatic islets has been studied using patch clamp techniques, and it has turned out that the behaviour of cells in intact islets differs significantly from the behaviour of dispersed cells. Classical Patch Clamp => Electrophysiology Planar Patch Clamp Automated Patch Clamp Device ...
Categories: Eponymous anatomical structures | Endocrine pancreas Major endocrine glands. ... The pancreas is an organ that serves two functions: exocrine - it produces pancreatic juice containing digestive enzymes. ... Alpha cells are endocrine cells in the islets of Langerhans of the pancreas. ... Beta cells are a type of cell in the pancreas in areas called the islets of Langerhans. ... Delta cells are somatostatin producing cells. ... PP cells are pancreatic polypeptide producing cells in the islets of Langerhans in the pancreas. ...
The idea of introducing isletcells into the bodies of diabetic patients is quite attractive because the major complications of the disease are caused because insulin injections do not accurately mimic the natural concentrations of insulin produced by the body in response to a person's diet.
This idea of encapsulating cells from the Islets of Langerhans is an old one, but finding a biocompatable method of encapsulating and inserting isletcells into the body has been a mystery for decades, until recently.
The encapsulated isletcells then respond to glucose levels in the body by secreting insulin, which is then taken up by blood vessels which lead to the liver and assist in metabolism.
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