Anatomy Of the Spine

Anatomy Of The Spine

The human spine is a complex anatomic structure that is the scaffolding for the entire body. It provides several important functions, including:

Protecting the spinal cord and nerves
Structural support for the body, allowing us to stand upright. The spine supports about half the weight of the body.

The average person is born with 33 individual bones (the vertebrae) that interact and connect with each other through flexible joints called facets. By the time a person becomes an adult most have only 24 vertebrae because some vertebrae at the bottom end of the spine fuse together during normal growth and development. Sometimes a person may have an additional vertebra, which is called a transitional body and is usually found at the sixth level of the lumbar area.

The bottom of the spine is called the sacrum. It is made up of several vertebral bodies usually fused together as one. The remaining small bones or ossicles below the sacrum are also fused together and called the tailbone or coccyx. The spine above the sacrum consists of:

Seven bones in the neck—the cervical spine
12 bones in the chest—the thoracic spine
Five bones in the lower back—the lumbar spine

The spinal column combines strong bones, unique joints, flexible ligaments and tendons, large muscles and highly sensitive nerves. While many of us take the benefits of a healthy spine for granted, spinal pain is a sharp reminder of how much we depend on our back in daily life.