Spinal Anatomy - Vid

Your spine is your body’s main support structure. It consists of 33 vertebrae, which are small circular bones stacked on top of one another to form the spinal column. The spine is divided into five regions:

  •         Cervical: This is the neck region of the spine. It consists of seven vertebrae labeled C1 to C7. The bones in the cervical region of the spine allow the head to nod and swivel.
  •         Thoracic: Is in the mid back and consists of 12 vertebrae labeled T1 to T12. These bones serve as attachment points to the ribcage.
  •         Lumbar: Commonly known as the low back, this region is made up of five vertebrae labeled L1 to L5. This section of the spine is responsible for bearing the weight of your body and is most susceptible to pain and injury.
  •         Sacral: This region consists of five fused vertebrae labeled S1 to S5. These bones form a single solid bone called the sacrum which provides the attachment point for the pelvis.
  •         Coccygeal: Commonly known as the tailbone, this region is made up of four small vertebrae. These bones may be fused or separate. Together they form the coccyx—an attachment point for various muscles and ligaments.

The vertebrae of the spine’s five regions give your body its upright support and protect your spinal cord and nerve roots. The lumbar vertebrae (L1 to L5) are larger and bulkier compared to the rest of the spine. This is mainly due to the lumbar spine having to withstand immense pressure from the body’s weight and from everyday activities like lifting, bending and twisting.


Analyzing a Spinal Segment

It’s often easier to visualize what happens in the spine by taking a closer look at a single spinal segment. A spinal segment consists of two vertebrae, the intervertebral disc between them, two nerve roots that form the nerves that travel throughout the body and two facet joints that connect the two vertebrae to one another and allow a full range of motion.


Each individual vertebra is formed by a round block of bone called the vertebral body—a cylinder-shaped section of the bone at the front of the vertebrae. A bony ring attaches to each vertebral body.

As the vertebra are stacked on top of one another, these rings form a tube called the spinal canal. The canal surrounds and protects the spinal cord which travels through this channel and extends from the brain to the L2 vertebra.

Intervertebral Discs

The human spine consists of 23 discs. Each disc is made up of two parts—a spongy inner part called the nucleus, which acts like a shock absorber between each vertebra, and a strong outer ligament surrounding the nucleus which connects each vertebra together.

Facet Joints

Facet joints are located on the back of the spinal column. There are two facet joints between each pair of vertebrae—one on each side of the spine. These pairs of bony knobs connect each vertebra to enable flexibility and motion.

The surfaces of facet joints are covered with cartilage, which is a smooth and rubbery material. The cartilage helps with movement as it allows the bones to move against each other without any direct bone-on-bone friction.

Nerve Roots

There are two nerve roots that exit the sides of each spinal segment. These nerves are responsible for carrying nerve impulses throughout the body to initiate movement and feeling.

Each region of the spine has a fixed number of nerve roots that exit the spinal canal and branch out into different parts of the body.

When Should You See an Orthopaedist?

Your spine is a delicate and complex structure that is susceptible to injures and a variety of spine conditions. As you age, different segments and parts of your spine, such as the vertebrae, discs and facet joints, suffer wear and tear. This can lead to degenerative conditions like osteoarthritis, herniated discs, spinal stenosis and sciatica.

Athletes, people who engage in strenuous physical activity and accident victims may suffer from painful and debilitating back injuries.

If your back pain is interfering with your ability to enjoy life and conventional treatments like rest and over-the-counter pain medication aren’t helping, you may benefit from seeing a skilled orthopaedist.

At Non-Surgical Orthopaedics in Marietta and Carrollton, we offer non-surgical pain management solutions for a variety of acute and chronic spine conditions.

Schedule your appointment with one of our experienced physicians by calling 770-421-1420.