Which one of the following is not a disorder of skeletal system?

Options

A. Atherosclerosis
B. Arthritis
C. Rickets
D. Osteoporosis

Explanation

To determine which of the following is not a disorder of the skeletal system, we will analyze each option provided: Atherosclerosis, arthritis, rickets, and osteoporosis.

### Step-by-Step Solution:

1. **Identify the Disorders**:
- **Atherosclerosis**: This condition involves the narrowing and hardening of arteries due to cholesterol accumulation. It affects the cardiovascular system, not the skeletal system.
- **Arthritis**: This is an inflammatory condition affecting the joints, which are part of the skeletal system. It causes pain and swelling.
- **Rickets**: This disorder is characterized by weak and soft bones, often due to vitamin D deficiency. It directly affects the skeletal system.
- **Osteoporosis**: This condition involves the weakening of bones due to loss of calcium and vitamin D, making bones more susceptible to fractures. It is also a skeletal disorder.

2. **Compare the Options**:
- Atherosclerosis is related to blood vessels and cardiovascular health.
- Arthritis, rickets, and osteoporosis are all disorders that directly affect the bones and joints.

3. **Conclusion**:
- The condition that is not a disorder of the skeletal system is **Atherosclerosis**.

### Final Answer:
**Atherosclerosis** is not a disorder of the skeletal system.

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