Select the correct statement with respect to locomotion in humans

Options

A. The vertebral column has 10 thoracic vertebrae
B. The joint between adjacent vertebrae is a fibrous joint
C. A decreased level of progesterone causes osteoporosis in old people
D. Accumulation of uric acid crystals in joints causes their inflammation.

Answer

To determine the correct statement regarding locomotion in humans, we will analyze each of the provided options step by step.

### Step-by-Step Solution:

1. **Evaluate the First Statement:**
- The first statement claims that the vertebral column has 10 thoracic vertebrae.
- **Fact Check:** In humans, the vertebral column actually consists of 12 thoracic vertebrae, not 10.
- **Conclusion:** This statement is incorrect.

2. **Evaluate the Second Statement:**
- The second statement states that the joint between adjacent vertebrae is a fibrous joint.
- **Fact Check:** The joints between adjacent vertebrae are classified as cartilaginous joints, which allow for slight movement. Fibrous joints do not allow for movement.
- **Conclusion:** This statement is incorrect.

3. **Evaluate the Third Statement:**
- The third statement mentions that a decreased level of progesterone causes osteoporosis in old people.
- **Fact Check:** Osteoporosis is primarily associated with a decreased level of estrogen, particularly in postmenopausal women, rather than progesterone.
- **Conclusion:** This statement is incorrect.

4. **Evaluate the Fourth Statement:**
- The fourth statement claims that the accumulation of uric acid crystals in joints causes inflammation.
- **Fact Check:** This condition is known as gout, where uric acid crystals accumulate in the joints, leading to painful inflammation.
- **Conclusion:** This statement is correct.

### Final Answer:
The correct statement with respect to locomotion in humans is: **The accumulation of uric acid crystals in joints causes their inflammation.**

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