How many vertebrae are classified as cervical?

In the human body, the cervical spine consists of seven vertebrae, which are designated as C1 through C7. These vertebrae are located in the neck region and are crucial for supporting the head, allowing for a range of movements such as rotation and bending. The first cervical vertebra, known as the atlas, supports the skull and enables nodding movements, while the second, known as the axis, allows for the rotation of the head. Understanding the anatomy and function of cervical vertebrae is essential in the context of oncology, particularly when discussing conditions that may affect this region, such as metastatic disease or cervical spine injuries.

The other options do not represent the correct number of cervical vertebrae in the human neck. Five, twelve, and twenty-four vertebrae do not align with the established anatomical definitions and classifications in human anatomy. Thus, the correct answer confirms the well-known fact that there are seven cervical vertebrae.