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Alpha Cells
Alpha cells (α cells) are endocrine cells that are found in the Islets of Langerhans in the pancreas. Alpha cells secrete the peptide hormone glucagon in order to increase glucose levels in the blood stream. Discovery Islets of Langerhans were first discussed by Paul Langerhans in his medical thesis in 1869. This same year, Laguesse named them after Langerhans. At first, there was a lot of controversy about what the Islets were made of and what they did. It appeared that all of the cells were the same within the Islet, but were histologically distinct from acini cells. Laguesse discovered that the cells within the Islets of Langerhans contained granules that distinguished them from acini cells. He also determined that these granules were products of the metabolism of the cells in which they were contained. Michael Lane was the one to discover that alpha cells were histologically different than beta cells in 1907. Before the function of alpha cells was discovered, the function o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pancreatic Islets
The pancreatic islets or islets of Langerhans are the regions of the pancreas that contain its endocrine (hormone-producing) cells, discovered in 1869 by German pathological anatomist Paul Langerhans. The pancreatic islets constitute 1–2% of the pancreas volume and receive 10–15% of its blood flow. The pancreatic islets are arranged in density routes throughout the human pancreas, and are important in the metabolism of glucose. Structure There are about 1 million islets distributed throughout the pancreas of a healthy adult human, each of which measures an average of about 0.2 mm in diameter.:928 Each islet is separated from the surrounding pancreatic tissue by a thin fibrous connective tissue capsule which is continuous with the fibrous connective tissue that is interwoven throughout the rest of the pancreas.:928 Microanatomy Hormones produced in the pancreatic islets are secreted directly into the blood flow by (at least) five types of cells. In rat islets, endocrine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |