In old age, stiffness of joints is due to the

Options

A. higher viscosity of synovial fluid
B. decreases in synovial fluid
C. increase in synovial fluid
D. none of above

Answer

### Step-by-Step Solution:

1. **Understanding Synovial Joints**:
- Synovial joints, such as those in the knees, have a synovial cavity that contains synovial fluid. This fluid is crucial for lubrication, allowing smooth movement between the bones.

2. **Role of Synovial Fluid**:
- The synovial membrane secretes synovial fluid, which lubricates the joint and reduces friction during movement. This fluid is essential for maintaining joint flexibility and function.

3. **Aging and Joint Stiffness**:
- As individuals age, the production of synovial fluid decreases. This reduction leads to inadequate lubrication in the joints, resulting in stiffness and discomfort.

4. **Symptoms of Joint Stiffness**:
- Older adults often experience pain and stiffness in their joints, particularly in the knees. This stiffness is primarily due to the decreased amount of synovial fluid.

5. **Underlying Conditions**:
- Conditions such as arthritis or inflammation can exacerbate the stiffness of joints. These conditions can lead to swelling and further decrease the production of synovial fluid.

6. **Conclusion**:
- Therefore, the stiffness of joints in old age is primarily due to the decrease in synovial fluid, which is essential for joint lubrication and movement.

### Final Answer:
In old age, stiffness of joints is due to the **decrease in the synovial fluid**.

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