The cervical spine anatomy summary is as follows: 1) The cervical spine consists of 7 vertebrae that support the head and allow for movement. It contains bony structures like the vertebral bodies and ligaments that provide stability. 2) The atlas (C1) and axis (C2) have unique structures that facilitate rotation. The atlas supports the head and allows for flexion and extension while the axis provides most axial rotation through its odontoid process. 3) Intervertebral discs composed of the nucleus pulposus and annulus fibrosus act as shock absorbers between vertebrae. Along with facet joints and ligaments, they maintain stability while allowing motion.

1. ANATOMY OF CERVICAL SPINE
Neurosurgery pg

2. Introduction
 Spinal stability is maintained by a variety of anatomic
structures
 These structures include both osseous and ligamentous
component
 The vertebral body is the main axial load–bearing structure of
the spine.
 Its cylindric shape, bounded peripherally by cortical bone and
rostrocaudally by end plates.

3. Cervical vertebrae
 7 in number
 Two type :Typical C3 to C6 Atypical C1. C2. C7
 Body. No body Dens prominent
Bifid spinous process No spine. Spinous
process
Not bifid

4. Occipital cervical junction is defined by the complex junction of the occiput ,
atlas and axis stabilised by dens ligamentous network allowing for movement
in three direction

5.  The atlas is ring with prominent
lateral masses bilaterally
supporting the head’s weight
and permitting head flrxion and
extension
 There is no proper body and
smooth rounded intracanalicular
surface of the anterior arch
called fovea debris serves as a
facet articulating with the
odontoid

7.  The axis (C2) provides majority of axial rotation via its
odontoid process. ( dens) which projects superiorly from its
body
 This articulation is supported by transverse ligaments which
restricts anterior translation of the atlas with respect to dens

9. Ligaments
 C1 – occipital – anterior occipital
membrane, posterior occipital
membrane, lateral Atlanto
occipital membrane
 Occipito –C2 – apical ligament ,
rectorial membrane, alar
ligament
 C1- C2- anterior atlanto axial
ligament , posterior atlantoaxial
ligament, transverse ligament,
cruciate ligament

14. Intervertevral disc
 The intervertebral disk serves as a
shock absorber
 The primary stabilizing structure of
the motion segment.
 composed of the nucleus pulposus
(a hydrated core of proteoglycans
suspended in a loose collagen
network) located in the
posterocentral area of the disk and
the annulus fibrosus .
 In infants the water content of the
disc is 90% and this comes down to
about 70−80% in young adults.

15.  The annulus fbrosus is made of type I
collagen and is organized into
individual lamellae that are oriented
at a 60-degree angle.
 The very outer lamellae, also called
Sharpey’s fbers, are anchored directly
into the bony matrix at the periphery
of each vertebral body.
 The height of the vertebral body is
slightly greater anteriorly.
 Such a vertebral body angle, in
addition to the fexible disk, ensures
the naturally lordotic sagittal
curvature with the center

16.  Concentric axial loads cause equally distributed forces within
the disk,
 Eccentrically placed loads result in bulging of the annulus on
the side of the applied force and nucleus to the opposite
 Shearing and rotational forces are resisted by the annular
fibers.
 As the disk deteriorates, its isotropic load transfer properties
are lost and load transfer becomes concentrated at the
periphery (annular insertion) of the vertebral end plates.

17. End plates
 The vertebral EPs are entirely composed of cartilage in
infancy.
 A rim of ossifcation appears in the periphery of the
cartilaginous EP and this annular epiphysis fuses with theVB.
 The EPs merge with the lamellae of the inner annulus fibrosus
completing the encasement of the Neucleus pulposus.
 Blood vessels penetrate the EPs during foetal life but
involute later , possible origins for Schmorl nodes.

18. Blood supply
 The disc derives its nutrition from the
capillary bed in
 theVB adjacent to the EP.
 The arterial supply to this vascular bed is
derived from:
(a) the centrum branchesin the
VB supplying the central region of the EP
(b) from the ascending and
descending branches of arteries on the
anterolateral surface of theVB and
(c) from the anterior intraspinal
arcade on the posterior surface of the body.

19. Nerve supply
 fbres from the grey rami communicans join the sinuvertebral
nerve (recurrent nerve of luschka)
 The C1 and C2 sinuvertebral nerves also supply the
atlantoaxial joints and the dura of the posterior fossa.

20.  the facet joints provide
additional load-bearing and
stabilizing functions between
segmental levels.
 Their orientation serves to
facilitate or limit degrees of
motion .
 The cervical facets are coronally
oriented and resist translation
while facilitating fexion,
extension, and rotation.

21. Ligaments
 The anterior longitudinal ligament (ALL) with a stronger
atachment to theVB and the posterior longitudinal ligament
(PLL) with a stronger atachment to the posterior annulus
strengthen the disc, though they are not integral parts of the disc.
 The ALL and PLL act as multisegmental tension bands resisting
extension and fexion forces,
 Each disc forms a motion segment unit with the zygoapophyseal
(facet) joints at that level.
 The facet capsules, ligamentum favum, interspinous,
supraspinous and intertransverse ligaments are important in
maintaining the stability of the motion segment, while at the
same time allowing motion to occur.

22. Inter spinal ligament
 The spinal ligaments provide
passive stabilization of the
vertebral column.
 Their bone-to-bone interface
and elastic properties provide
both tension band and
translational support.

23. Paraspinal muscle
 The primary function is to stabilize the spinal column rather
than produce motion.

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