The human spine is made up of twenty-four spinal bones, called vertebrae. Vertebrae are stacked on top of one another to form the spinal column. The spinal column is the body's main upright support.

The cervical spine is formed by the first seven vertebrae. Doctors often refer to these vertebrae as C1 to C7. The cervical spine starts where the top vertebra (C1) connects to the bottom edge of the skull. The cervical spine curves slightly inward and ends where C7 joins the top of the thoracic spine. This is where the chest begins.

Each vertebra is formed by a round block of bone, called a vertebral body. A bony ring attaches to the back of the vertebral body. When the vertebrae are stacked on top of each other, the rings form a hollow tube. This bony tube surrounds the spinal cord as it passes through the spine. Just as the skull protects the brain, the bones of the spinal column protect the spinal cord.

As the spinal cord travels from the brain down through the spine, it sends out nerve branches between each vertebra called "nerve roots." These nerve roots join together to form the nerves that travel throughout the body and form the body's electrical system. The nerve roots that come out of the cervical spine form the nerves that go to the arms and hands. The thoracic spine nerves go to the abdomen and chest. The nerves coming out of the lumbar spine go to the organs of the pelvis, the legs, and the feet.

One way to understand the anatomy of the cervical spine is to look at a spinal segment. Each spinal segment includes two vertebrae separated by an intervertebral disc, the nerves that leave the spinal cord at that level, and the small facet joints that link each level of the spinal column.

An intervertebral disc is made of connective tissue. Connective tissue is the material that holds the living cells of the body together. Most connective tissue is made of fibers of a material called collagen. In some cases, the collagen fibers join together to form a structure like a rope. In other cases, the fibers are arranged like a piece of cloth, or knitted materials such as you find in a sweater. The disc is a specialized connective tissue structure that separates the two vertebral bodies of the spinal segment. The disc normally works like a shock absorber. It protects the spine against the daily pull of gravity. It also protects the spine during activities that put strong force on the spine, such as jumping, running, and lifting.

An intervertebral disc is made up of two parts. The center, called the nucleus, is spongy. It provides most of the ability to absorb shock. The nucleus is held in place by the annulus, a series of strong ligament rings surrounding it. Ligaments are strong connective tissues that attach bones to other bones.

Between the vertebrae of each spinal segment are two facet joints. The 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. A facet joint is made of small, bony knobs that line up along the back of the spine. Where these knobs meet, they form a joint that connects the two vertebrae. The alignment of the facet joints of the cervical spine allows freedom of movement as you bend and turn your neck.

The surfaces of the facet joints are covered by articular cartilage. Articular cartilage is a smooth, rubbery material that covers the ends of most joints. It allows the bone ends to move against each other smoothly, without pain.

Two spinal nerves exit the sides of each spinal segment, one on the left and one on the right. As the nerves leave the spinal cord, they pass through a small bony tunnel on each side of the vertebra. These tunnels are called the neural foramina.