National Certification Board for Therapeutic Massage & Bodywork (NCBTMB) Practice Exam

C2 is known as the Axis. It plays a critical role in the cervical spine, particularly in the range of motion of the head and neck. The Axis serves as a pivot point for the C1 vertebra (the Atlas), allowing for the rotation of the head. The unique structure of the Axis includes the odontoid process (or dens), which protrudes upward and fits into the Atlas, creating a joint that facilitates this rotary motion. This anatomical design is essential for functions such as turning the head side to side, making the Axis a key component of the cervical vertebral system.

In contrast, the Atlas, identified as C1, is specifically the first cervical vertebra that supports the skull. The term Apex generally refers to the tip or highest point of a structure and does not specifically denote a cervical vertebra. The inferior vertebral notch is part of the anatomy associated with vertebrae that allows for the passage of nerves and blood vessels but does not pertain to the designation of C2. Understanding these distinctions helps clarify the importance of the Axis in spinal and cranial movement.