To understand scoliosis, which causes
the spine to curve to the left or right, you first need to understand what
a normal spine looks like. There are four regions in your spine:
- Cervical Spine: This is your
neck, which begins at the base of your skull. It contains 7 small bones
(vertebrae), which doctors label C1 to C7 (the 'C' means cervical). The
numbers 1 to 7 indicate the level of the vertebrae. C1 is closest to the
skull, while C7 is closest to the chest.
- Thoracic Spine: Your
mid-back has 12 vertebrae that are labeled T1 to T12 (the 'T' means
thoracic). Vertebrae in your thoracic spine connect to your ribs, making
this part of your spine relatively stiff and stable. Your thoracic spine
doesn't move as much as the other regions of your spine, like the
cervical spine.
- Lumbar Spine: In your low
back, you have 5 vertebrae that are labeled L1 to L5 (the 'L' means
lumbar). These vertebrae are your largest and strongest vertebrae,
responsible for carrying a lot of your body's weight. The lumbar
vertebrae are also your last "true" vertebrae; down from this region,
your vertebrae are fused. In fact, L5 may even be fused with part of
your sacrum.
- Sacrum and Coccyx: The
sacrum has 5 vertebrae that usually fuse by adulthood to form one bone;
the coccyx-most commonly known as your tail bone-has 4 (but sometimes 5)
fused vertebrae.
From behind, the normal spine appears
straight. However, when viewed from the side, you'll see that the spine
has both inward and outward curves. These curves help our back carry our
weight and are also important for flexibility.
There are two types of curves in your
spine: kyphosis and lordosis. You can see those from the side view.
Kyphosis means the spine curves inward; lordosis means the spine curves
outward. There are two kyphotic and two lordotic spinal curves in a normal
spine. Your neck (cervical spine) and low back (lumbar spine) have a
lordotic curve. Your mid back (thoracic spine) and pelvis (sacrum) have a
kyphotic curve.
As you can probably tell from the
basic curves of the spine, it's a complex structure. Your spine is made up
of many parts. Your spinal column, also called your vertebral column, has
24 individual bones-those are your vertebrae. In between the vertebrae,
you have intervertebral discs that act like pads or shock absorbers. Each
disc is made up of a tire-like outer band (annulus fibrosus) and a
gel-like inner substance (nucleus pulposus).
Together, the vertebrae and the discs
provide a protective tunnel (spinal canal) for the spinal cord and spinal
nerves. The spinal cord runs from the brain down through most of the
spine. Nerves branch off the spinal cord at interval and exit through
openings called the foramen. From there, nerves go to various parts of
your body, helping you move and feel.
Besides the bones, discs, and nerves,
your spine has muscles, ligaments, and blood vessels. Muscles are strands
of tissues that act as the source of power for movement. Ligaments are the
strong flexible bands of fibrous tissue that link the bones together.
Tendons connect muscles to bones and discs. Blood vessels provide
nourishment. These parts work together to help you move, and they also
help stabilize your spine.
