What are goblet cells ?

Explanation

**Step-by-Step Solution:**

1. **Definition of Goblet Cells**: Goblet cells are specialized epithelial cells that are shaped like a goblet or cup. They are classified as simple columnar epithelial cells.

2. **Location of Goblet Cells**: These cells are primarily found in various mucous membranes, including the respiratory tract, the gastrointestinal tract (especially in the stomach and intestines), and other areas where mucus secretion is necessary.

3. **Function of Goblet Cells**: The main function of goblet cells is to secrete gel-forming mucins. Mucins are glycoproteins that, when hydrated, form a gel-like substance.

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