Odontoid process is associated with.

Options

A. Ulna
B. Axis vertebrae
C. Atlas vertebrae
D. Seventh cervical vertebrae

Answer

### Step-by-Step Solution:

1. **Identify the Odontoid Process**: The odontoid process, also known as the dens, is a bony projection that is located on the second cervical vertebra, which is referred to as the axis.

2. **Understand its Function**: The primary function of the odontoid process is to serve as a pivot point around which the first cervical vertebra (the atlas) rotates. This allows for the rotation of the head and neck.

3. **Locate the Associated Structures**:
- The **atlas** is the first cervical vertebra that supports the skull and allows for nodding movements.
- The **axis** is the second cervical vertebra, which contains the odontoid process.
- The **ulna** is a bone in the forearm and is not related to the cervical vertebrae.
- The **7th cervical vertebra** is the last in the cervical series and does not have a direct association with the odontoid process.

4. **Determine the Correct Association**: Since the odontoid process is a feature of the axis, the correct answer to the question is that the odontoid process is associated with the **axis vertebra**.

### Final Answer:
The odontoid process is associated with the **axis vertebra**.

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