lumbar (lower back), and sacral and coccygeal
Cervical.There are seven cervical vertebrae in
the neck. The first is called the atlas and resembles a
bony ring. It supports the head. The second is the
highly specialized axis. It has a bony prominence that
fits into the ring of the atlas, thus permitting the head to
rotate from side to side. The atlas and the axis are the
only named vertebrae; all others are numbered. See
figure 1-19. Each cervical vertebra has a transverse (or
intervertebral) foramen (fig. 1-19) to allow passage of
nerves, the vertebral artery, and a vein. The seventh
cervical vertebra has a prominent projection that can
easily be felt at the nape of the neck. This landmark
makes it possible for physicians to count and identify
the vertebrae above and below it.
Thoracic.There are 12 vertebrae in the thoracic
region. The thoracic vertebrae articulate with the
posterior portion of the 12 ribs to form the posterior
wall of the thoracic, or chest, cage.
Figure 1-17.Vertebral column: A. Left lateral view of vertebral column; B. Posterior view of vertebral column.