The main difference between alpha and beta cells is that alpha cells produce and secrete glucagon, whereas beta cells produce and secrete insulin.
Pancreas is both an organ and a gland. It is an elongated and tapered organ located behind the stomach in the abdominal cavity (in the upper left abdomen). It is surrounded by other organs such as the spleen, liver, and small intestine. There are three main parts in the pancreas anatomy, namely the head, neck, body, and tail. Pancreas has two functions: the exocrine function and the endocrine function. The exocrine function involves the production of enzymes that aid in digestion, while the endocrine function involves sending out hormones that control the amount of sugar in the bloodstream. Furthermore, the endocrine pancreas has cells that produce and secrete hormones such as glucagon, insulin, somatostatin, etc. These cells exist as small cell clusters known as islets. Moreover, these islets have three types of cells; they are alpha cells, beta cells, and delta cells.
Key Areas Covered
1. What are Alpha Cells
– Definition, Abundance, Function
2. What are Beta Cells
– Definition, Abundance, Function
3. Difference Between Alpha and Beta Cells
– Comparison of Key Differences
Key Terms
Alpha Cells, Beta Cells, Pancreas
What are Alpha Cells
Alpha cells are one of the three types of cells in the pancreas. They are also known as A cells. 33%- 45% of the cells in the pancreas are alpha cells. These cells produce and secrete the hormone glucagon, which is a peptide hormone. In fact, it is a hormone that regulates hepatic glucose production (that is, to release glucose from glycogen stores in the liver). Hence, alpha cells are endocrine cells.
Moreover, glucagons bind with the receptors on hepatocytes (liver cells) or kidneys. Also, after the binding, an enzyme known as glycogen phosphorylase is activated inside the hepatocytes, this enzyme is responsible for the hydrolysis of glycogen to glucose. And, this, in turn, increases blood glucose levels.
What are Beta Cells
Beta cells are one of the three types of cells in the pancreas. They are endocrine cells. They produce, store, and release insulin, which is a hormone responsible for the reduction of blood glucose levels. In fact, about 65-80% of the cells in the islets are beta cells.
Beta cells also produce hormones such as amylin and C-peptide. Amylin slows down the rate at which glucose enters the blood, while C-peptide prevents neuropathy and other vascular deterioration-related symptoms of diabetes mellitus.
When the body’s immune system mistakenly destroys the beta cells, it is called type I diabetes. Furthermore, the pancreas can’t produce insulin without beta cells. Type 2 diabetes is a condition that occurs when the body fails to produce an adequate amount of insulin required for regulating blood sugar levels.
Difference Between Alpha and Beta Cells
Definition
Alpha cells are one of the three types of cells in the pancreas and produce and secrete glucagon, whereas beta cells are another type of cell in the pancreas and produce and secrete insulin hormone.
Abundance
Alpha cells are less abundant, while beta cells are more abundant in the pancreas.
Percentage Count
About 33-46% of the cells in islets are alpha cells, whereas about 65-80% of the cells in the islets are beta cells.
Function
Alpha cells produce and secrete the hormone glucagon, whereas beta cells mainly produce and secrete the hormone insulin.
Secreting Hormones
Alpha cells secrete glucagon, while beta cells secrete insulin, amylin, and C-peptide.
Conclusion
Pancreas is an organ located in the abdominal cavity. Pancreas has both exocrine and endocrine functions. The islets of the pancreas have three types of cells in them. Alpha and beta cells are two types of cells. The main difference between alpha and beta cells is that alpha cells produce and secrete glucagon, whereas beta cells produce and secrete insulin.
Reference:
1. “Beta Cell.” Science Direct.
2. “Pancreatic α-cells – The unsung heroes in islet function.” PubMed. National Library of Medicine.
Image Courtesy:
1. “Blausen 0701 PancreaticTissue” By Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work (CC BY 3.0) via Commons Wikimedia
2. “Human beta cells” By Wikimaji – Own work (CC BY 4.0) via Commons Wikimedia
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