Alpha cells of islets of langerhans secrete____

Answer

**Step-by-Step Solution:**

1. **Identify the Location**: The alpha cells are located in the islets of Langerhans, which are found in the pancreas.

2. **Understand the Function of the Pancreas**: The pancreas serves both endocrine and exocrine functions. The endocrine function involves hormone production that is released directly into the bloodstream, while the exocrine function involves the secretion of digestive enzymes through ducts.

3. **Focus on the Endocrine Role**: Since the question pertains to the secretion of hormones, we will focus on the endocrine role of the pancreas.

4. **Identify the Types of Cells**: The islets of Langerhans contain different types of cells, including alpha cells, beta cells, gamma cells, and delta cells. Each type of cell is responsible for producing specific hormones.

5. **Determine the Hormone Secreted by Alpha Cells**: The alpha cells specifically secrete glucagon.

6. **Understand the Role of Glucagon**: Glucagon plays a crucial role in increasing blood glucose levels. It causes hyperglycemia by promoting gluconeogenesis in the liver and stimulating the breakdown of glycogen into glucose.

7. **Conclude the Answer**: Therefore, the alpha cells of the islets of Langerhans secrete glucagon.

**Final Answer**: Alpha cells of islets of Langerhans secrete glucagon.

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