Give the location and function of mast cells.

Explanation

### Step-by-Step Solution:

1. **Identify the Location of Mast Cells:**
- Mast cells are primarily located in the **matrix of areolar connective tissue**. This type of connective tissue is found throughout the body, particularly around blood vessels, nerves, and organs.

2. **Understand the Function of Mast Cells:**
- The primary function of mast cells is to **produce heparin**, which is an anticoagulant. Heparin helps to prevent blood clotting, ensuring that blood remains in a fluid state and can flow freely through the circulatory system.

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