The spinal cord and nerves carry impulses to and from your brain. The spine is a collection of bones, ligaments, discs, and other tissue that support and protect the spinal cord and the spinal nerves. Unfortunately, if any of this protective tissue presses on a nerve or stretches it, your brain interprets that pressure as pain, tingling, or some other unpleasant sensation, and this sensation feels like it’s coming from a distant part of your body (for example, your foot).

The spine is a set of alternating bones and discs. Each bone is called a vertebra. The discs act like shock absorbers for the vertebrae. They also make it possible for you to bend your spine. Each disc has two layers. The inner layer is the nucleus and the outer layer is the annulus. Think of these two layers like a car tire. The outer layer (the annulus or the tire’s rubber) is strong, and the inner layer (the nucleus or the tire's air) supplies the cushion.

The vertebrae are connected to one another by the discs and by ligaments. Muscles attached to the vertebrae make it possible for you to stand up and to move.

Click on any of the graphics for an enlarged view.

Nerves transmit pain and other sensations to your brain. They also send signals from your brain to your muscles.

Where nerves travel near bones, they can be irritated, causing pain.

Your skeleton supports your body.

Here's a close-up of the bones in your spine, the vertebrae.

Here are two views of your lumbar (lower back) vertebrae.

Herniated disc - here are two views of the spinal cord and a spinal nerve. The nerve is compressed by a herniated disc.