|
Cervical Spine
The neck region of the spine is known as the Cervical Spine.
This region consists of seven vertebrae, which are abbreviated C1 through
C7 (top to bottom). These vertebrae protect the brain stem and the spinal
cord, support the skull, and allow for a wide range of head movement.
 | 1 Spinous Process
2 Lamina
3 Zygapophysial Joint (Facet)
4 Posterior Tubercle
5 Foramen
6 Pedicle
7 Body |
The first cervical vertebra (C1) is called the Atlas. The Atlas
is ring-shaped and it supports the skull. C2 is called the Axis.
It is circular in shape with a blunt tooth-like structure (called the
Odontoid Process or "dens") that projects upward into the Atlas.
Together, the Atlas and Axis enable the head to rotate and turn. The other
cervical vertebrae (C3 through C7) are shaped like boxes with small spinous
processes (finger-like projections) that extend from the back of the vertebrae.
Thoracic Spine
Beneath the last cervical vertebra are the 12 vertebrae of the
Thoracic Spine. These are abbreviated T1 through T12 (top to bottom).
T1 is the smallest and T12 is the largest thoracic vertebra. The thoracic
vertebrae are larger than the cervical bones and have longer spinous processes.
 | 1 Body
2 Spinous Process
3 Transverse Process
4 Pedicle
5 Foramen
6 Articular Process |
In addition to longer spinous processes,
rib attachments add to the thoracic spine's strength. These structures
make the thoracic spine more stable than the cervical or lumbar regions.
In addition, the rib cage and ligament systems limit the thoracic spine's
range of motion and protects many vital organs.
Lumbar Spine
The Lumbar Spine has 5 vertebrae abbreviated L1 through
L5 (largest). The size and shape of each lumbar vertebra is designed to
carry most of the body's weight. Each structural element of a lumbar vertebra
is bigger, wider and broader than similar components in the cervical and
thoracic regions.
 | 1 Body
2 Spinous Process
3 Articular Process
4 Transverse Process
5 Foramen
6 Pedicle |
The lumbar spine has more range of motion than the thoracic spine, but
less than the cervical spine. The lumbar facet joints allow for significant
flexion and extension movement but limits rotation.
Sacral Spine
The Sacrum is located behind the pelvis. Five bones, abbreviated
S1 through S5, fused into a triangular shape, form the sacrum. The sacrum
fits between the two hip bones connecting the spine to the pelvis. The
last lumbar vertebra (L5) articulates (moves) with the sacrum.
Immediately below the sacrum are five additional bones, fused together
to form the Coccyx (tailbone).
|
