The bones which make up the spine are called vertebrae.

The shape of the vertebrae in each region of the spine is different. This is because the vertebrae in each region of the spine have different load to carry and different function.

Each vertebrae has:

• Vertebral body: it is a strong piece of bone that bears the body weight. The outer part of the vertebrae is made of a stronger bone material (cortical), while inside the cancellous bone is spongy and flexible.
• Facet joints: these are the articulations of the vertebrae. Each vertebrae has four joints (facet joints), the two in the upper part that connect with the vertebrae above and the two in the lower part that connect the vertebrae underneath.
• Pedicle: strong bony part of each side of the vertebra that connect the anterior vertebral body and posterior arch
• Lamina: for each vertebra, two lamina connect the pedicles to the spinous process
• Spinous process: the portion of the vertebra that protudes posteriorly from the spinal column. The spinous process creates bumps felt on the midline of the back.
• Transverse process: in each side of the vertebra, the transverse process protudes laterally, playing a role in stability.