How many vertebrae are in the human spine?

The vertebral column begins with 7 cervical vertebrae in the neck, followed by 12 thoracic vertebrae in the upper and mid-back and 5 lumbar vertebrae in the lower back. Below these are 5 sacral vertebrae that fuse into the sacrum and usually 4 coccygeal vertebrae that fuse into the coccyx, or tailbone. That gives the classic total of 33 vertebrae, although the number can vary slightly between individuals. The spine supports body weight, protects the spinal cord, and allows flexibility and movement. Its curved shape also helps absorb shock during walking and running.