Wikia

Psychology Wiki

Islets of Langerhans

Talk0
34,117pages on
this wiki
Revision as of 06:15, June 4, 2007 by Dr Joe Kiff (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)


Islet
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.
PhloxBotAdded by PhloxBot
Langerhanssche Insel
Islets of Langerhans, haemalum-eosin stain.
PhloxBotAdded by PhloxBot
Gray1105
Section of pancreas of dog. X 250.
PhloxBotAdded by PhloxBot

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.

Cell typesEdit

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).

Paracrine feedbackEdit

The paracrine feedback system of the islets of Langerhans has the following structure:

  • Insulin: Activates beta cells and inhibits alpha cells.
  • Glucagon: Activates alpha which activates beta cells and delta cells.
  • Somatostatin: Inhibits alpha cells and beta cells.

Electrical activityEdit

Electrical activity of pancreatic islets has been studied using patch clamp techniques, and it has turned out that the behavior of cells in intact islets differs significantly from the behaviour of dispersed cells.

As a treatment for type I diabetesEdit

Since the islets of Langerhans are destroyed in type I diabetes, clinicians and researchers are actively pursuing islet transplantation technology as a means of curing this disease.


External linksEdit


This page uses Creative Commons Licensed content from Wikipedia (view authors).
Advertisement | Your ad here

Around Wikia's network

Random Wiki