File:Pancreas cartoon.jpg

Endocrine Pancreas - Beta Cell Secretion

Pancreatic Endocrine Tissue Comprises 1%, or Less, of the Pancreas and Is Organized as Clusters of Cells Dispersed throughout the Exocrine Pancreas. Glucose-dependent insulin secretion from β cells, by analogy to excitation–contraction coupling in muscle, is referred to as stimulus-secretion coupling.

1. Glucose stimulation elicits depolarisation of the cell membrane and electrical activity in β cells.
2. Opens calcium ion (Ca ²⁺) channels in the membrane that respond to changes in voltage—voltage-dependent calcium channels (VDCCs)
3. Allow Ca ²⁺ entry and action potential firing.
4. Ca ²⁺ acts on the exocytotic machinery to stimulate fusion of insulin-containing vesicles with the plasma membrane.
5. Vesicle secretion into the bloodstream.

(text modified from original reference)

Reference

MacDonald PE & Rorsman P. (2006). Oscillations, intercellular coupling, and insulin secretion in pancreatic beta cells. PLoS Biol. , 4, e49. PMID: 16464129 DOI.

Copyright

© 2006 MacDonald and Rorsman. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Cite this page: Hill, M.A. (2024, April 27) Embryology Pancreas cartoon.jpg. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/File:Pancreas_cartoon.jpg

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