Which of the following lubricates ligament and tendon and is the important constituent of synovial fluid?

Options

A. Chitin
B. Lipids
C. Hyaluronidase
D. Hyaluronic acid

Answer

To solve the question "Which of the following lubricates ligament and tendon and is the important constituent of synovial fluid?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Function of Synovial Fluid**:
- Synovial fluid is a thick liquid found in the cavities of synovial joints. Its primary function is to lubricate the joints, allowing for smooth movement between the bones.

2. **Identify the Components of Synovial Fluid**:
- Synovial fluid contains various components that contribute to its lubricating properties. One of the key components is hyaluronic acid.

3. **Role of Hyaluronic Acid**:
- Hyaluronic acid (HA) is a substance that helps maintain the viscosity of synovial fluid. It is crucial for reducing friction between the moving parts of the joints and also plays a role in reducing inflammation.

4. **Conclusion**:
- Given the information about synovial fluid and its components, the substance that lubricates ligaments and tendons and is an important constituent of synovial fluid is **hyaluronic acid**.

### Final Answer:
The correct answer is **hyaluronic acid**.

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