Question

Axis vertebrae are identified by
A. Olecranon process
B. Odontoblast
C. Odontoid process
D. None of the above

Answer 1

Vertebrae are serially arranged units that make up the vertebral column. In humans, there are twenty-six vertebrae. These vertebrae are classified into five different types. These five types of vertebrae are cervical, thoracic, lumbar, sacral, and coccyx.

Complete answer: The axis vertebrae is a type of cervical vertebrae. The cervical vertebrae are found in the neck region. They constitute the first seven vertebrae. The axis is the second cervical vertebrae. It is like a pivot on which the atlas or the first cervical vertebrae turns in the rotary movements of the head. From the body of the axis vertebrae, a process of bones rises that is known as the odontoid peg or the odontoid process. The odontoid peg articulates with the back of the anterior arch of the atlas. It is held in position with the help of transverse ligaments of the atlas. The lateral mass of the atlas articulates with the corresponding facets of the axis vertebrae. These facets are placed on each side of the odontoid peg. The atlas moves around the odontoid peg of the axis which forms a pivot joint over which the head rotates. Thus, based on the above information, we can conclude that the axis vertebrae are identified by the odontoid process.
Hence, the correct answer is option C.

Note: Between two adjacent vertebrae, intervertebral discs are present. Intervertebral discs are the disc or pads of fibrous cartilage. They provide flexibility to the vertebral column. The spinal cord passes through a hollow central portion in each vertebra.