Cervical vertebrae
The typical cervical vertebrae
(C3-6), have a small, transversely located, oblong body with slightly elongated anteroinferior borders. The result is anteroposterior overlapping of the bodies in the articulated column.
to show the cervical zygapophyseal joints.
A lateral projection is necessary
Accurate radiographic demonstration of the intervertebral foramina requires
a 15-degree longitudinal angulation of the central ray and a 45-degree medial rotation of the patient (or a 45-degree medial angulation of the central ray).
The seventh vertebra is
also atypical and is slightly modified to join the thoracic spine.
The atlas consists of
an anterior arch, a posterior arch, two lateral masses, and two transverse processes. The anterior and posterior arches extend between the lateral masses.
The transverse processes of the atlas
are longer than those of the other cervical vertebrae, and they project laterally and slightly inferiorly from the lateral masses.
The spinous processes
are short, have double-pointed (bifid) tips, and are directed posteriorly and slightly inferiorly.
The transverse processes of the typical cervical vertebra
arise partly from the sides of the body and partly from the vertebral arch. These processes are short and wide, and are perforated by the transverse foramina.
Together the processes form short, thick columns of bone called
articular pillars.
The first two cervical vertebrae are
atypical in that they are structurally modified to join the skull.
Each lateral mass
bears a superior and an inferior articular process.
The laminae of the axis are
broad and thick.
the joint of the axis, which differ in position and direction from the other cervical zygapophyseal joints, are
clearly visualized in an AP projection if the patient is properly positioned.
The intervertebral foramina of the cervical region are
directed anteriorly at a 45-degree angle from the midsagittal plane of the body. The foramina are also directed at a 15-degree inferior angle to the horizontal plane of the body.
The spinous process of this vertebra is
easily palpable at the posterior base of the neck. It is convenient to use this process as a guide in localizing other vertebrae.
The fibrocartilaginous articulating surfaces of the articular pillars contain
facets.
The inferior articular processes of the axis
have the same direction as the processes of the succeeding cervical vertebrae.
The spinous process is
horizontal in position.
The ring formed by the arches
is divided into anterior and posterior portions by a ligament called the transverse atlantal ligament.
The zygapophyseal facet
joints of the second through seventh cervical vertebrae lie at right angles to the midsagittal plane and are clearly shown in a lateral projection
The palpable tips of the spinous processes
lie at the level of the interspace below the body of the vertebra from which they arise.
The superior processes
lie in a horizontal plane, are large and deeply concave, and are shaped to articulate with the occipital condyles of the occipital bone of the cranium.
The superior and inferior articular processes are
located posterior to the transverse processes at the point where the pedicles and laminae unite.
The laminae are
narrow and thin.
The pedicles of the typical cervical vertebra
project laterally and posteriorly from the body, and their superior and inferior vertebral notches are nearly equal in depth.
The seventh cervical vertebra (C7)
termed the vertebra prominens, has a long, prominent spinous process that projects almost horizontally to the posterior.
The anterior portion of the ring receives
the dens (odontoid process) of the axis, and the posterior portion transmits the proximal spinal cord.
The axis
the second cervical vertebra, has a strong conical process arising from the upper surface of its body. This process, called the dens or odontoid process, is received into the anterior portion of the atlantal ring to act as the pivot or body for the atlas.
At each side of the dens on the superior surface of the vertebral body are
the superior articular processes, which are adapted to join with the inferior articular processes of the atlas.
The atlas
the first cervical vertebra (C1), is a ringlike structure with no body and a very short spinous process
All cervical vertebrae contain
three foramina: the right and left transverse foramina and the vertebral foramen.
transverse foramina
transmission of the vertebral artery and vein, and present a deep concavity on their upper surfaces for passage of the spinal nerves.