C1 and C2 are commonly known as which bones?

• A. Atlas and Axis
• B. Cervical 1 and Cervical 2
• C. First and Second cervical vertebrae
• D. Neck vertebrae pair

Answer: (A)

C1 and C2 have specialized names because they form a unique joint that enables head movement. The first cervical vertebra, called the atlas, supports the skull and has a ring-like shape with no vertebral body, allowing the head to nod up and down. The second cervical vertebra, called the axis, has a projection called the dens (odontoid process) that extends upward to form a pivot for rotation, enabling the head to turn side to side. Together, they make the atlantoaxial region, which is why these two bones are collectively known by these particular names. The other phrasings are less precise: they describe the same bones in less standard terms, whereas atlas and axis are the conventional, widely used names in anatomy and clinical practice.