What is the Difference Between Typical and Atypical Vertebrae?

The difference between typical and atypical vertebrae lies in their structure and function. Vertebrae are the bones that make up the vertebral column, which protects the spinal cord. They are classified into two categories: typical and atypical vertebrae.

Typical Vertebrae have a standard vertebral anatomy, which includes a vertebral body and a vertebral arch made up of laminae and pedicles. These vertebrae are found in most adults and primarily consist of thoracic, lumbar, and certain cervical vertebrae.

Atypical Vertebrae are modified structures that deviate from the standard vertebral anatomy due to their position and function. These vertebrae are found in specific regions of the vertebral column and include:

C1, C2, and C7 of the cervical vertebrae
T1, T9, T10, T11, and T12 of the thoracic vertebrae
L5 of the lumbar vertebrae

Some examples of atypical vertebrae are:

C1 (Atlas): This vertebra lacks a vertebral body and has two bilateral masses that articulate with the occipital condyles of the skull.
C2 (Axis): This vertebra contains a vertical projection called the dens, which articulates with the atlas.
C7: This vertebra has a non-bifid, longer spinous process compared to other cervical vertebrae.
L5 (Lumbar): This vertebra has the largest vertebral body and transverse processes, and it has the most inferiorly located discovertebral unit in the human vertebral column.

In summary, typical vertebrae follow the standard vertebral anatomy and are found in most adults, while atypical vertebrae have modified structures due to their specific functions and positions within the vertebral column.