The Spine

There are 33 vertebrae.

• 7 cervical
• 12 thoracic
• 5 lumbar
• 5 sacral
• 4 coccygeal

The spine has curves.

• cervical curve concave to the back
• thoracic curve convex to the back
• lumbar curve concave to the back
• sacral/coccygeal convex to the back

We begin life with one curve - rounded, convex to the back of the body. This curve is known as a primary curve, and the thoracic & sacral/coccygeal curves are primary curves.

As we develop, we learn to hold our head up and develop a secondary curve at the cervical spine, and later we develop a another secondary curve in the lumbar spine.

The vertebrae are numbered from top to bottom with the first letter of the section C1 to C7, T1-T12, L1-L5.

The first two cervical vertebrae have special names.

• C1 is the atlas. (named after Atlas)
• C2 is the axis. It has a pivot point for C1 to rotate.

Variation happens, and it's very normal.
Sometimes there are more or less vertebrae.

Each Vertebra, All Your Vertebrae
One vertebra (short a)
​Two or more vertebrae (long a)