The bone not associated with the rib case/cage is

Options

A. 1)Thoracic vertebrae
B. 2)Sternum
C. 3)Lumbar vertebrae
D. 4)Ribs

Answer

To determine which bone is not associated with the rib cage, we will analyze the options provided:

1. **Understanding the Rib Cage**: The rib cage is a bony structure that surrounds and protects vital organs such as the heart and lungs. It consists of several components.

2. **Components of the Rib Cage**:
- **Thoracic Vertebrae**: There are 12 thoracic vertebrae that form part of the rib cage structure. Each rib is attached to a thoracic vertebra, making this option associated with the rib cage.
- **Sternum**: The sternum, or breastbone, is located at the front of the rib cage and connects to the ribs. Therefore, this option is also associated with the rib cage.
- **Ribs**: The rib cage consists of 24 ribs (12 pairs), which directly form the structure of the rib cage. Thus, this option is associated with the rib cage as well.
- **Lumbar Vertebrae**: The lumbar vertebrae are located in the lower back and do not connect to the rib cage. Therefore, this option is not associated with the rib cage.

3. **Conclusion**: Based on the analysis, the bone that is not associated with the rib cage is the **lumbar vertebrae**.

**Final Answer**: The bone not associated with the rib cage is the **lumbar vertebrae** (Option 3).

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