vertebral column

1. THE VERTEBRAL COLUMN
BY, SHARAYU KAPURE
MEHAR KINAN AKBAR
DIVYA GONDHALI
OM DABHI
MANUJ PATEL
(BATCH K4)

2. CONTENT
• Introduction
• Joints of vertebral column
• Movements of vertebral column
• Curvatures of vertebral column
• Vasculature of vertebral column
• Nerves of vertebral column
• Conclusion

3. INTRODUCTION
• The vertebral column, also known as spine or
backbone, is a flexible column that forms a part of the
axial skeleton.
• It emerges from the neck at the base of the skull and
extends up to the tail region.
• The number of bones in the vertebral column in
humans is 26. Generally, there are 7 cervical vertebrae,
12 thoracic vertebrae, 5 lumbar, 1 sacral (fused) and 1
coccygeal (fused) vertebrae.
• The length of the backbone in humans ranges from
61cm to 71cm.

4. JOINTS OF VERTEBRAL COLUMN
The joints of the vertebral column include the following:
 Joints of the vertebral bodies.
 Joints o the vertebral arches.
 The craniovertebral (atlanto-axial and atlanto-occipital) joints.
 The costovertebral joints
 Sacro-iliac joints
• JOINTS OF THE VERTREBRAL BODIES:
->Intervertebral discs: The main joints of the vertebral bodies from C2 to S1 are secondary cartilaginous joints
(symphyses, singular: symphysis) called intervertebral (IV) discs. The articular surfaces of adjacent vertebral bodies
are lined by sheets of hyaline cartilage (vertebral end-plates) and linked together by the fibrocartilaginous IV
discs.The IV discs are designed for weight-bearing and strength and increase in thickness as the vertebral column
descends. The gelatinous nature of the nucleus pulposus promotes flexibility of the vertebral column and acts as a
shock absorber, absorbing compression forces between vertebrae.
->Unconvertable joints: In addition to the intervertebral discs, the vertebral bodies of the typical cervical
vertebrae (C3-C7) bear small synovial joints called uncovertebral joints (of Luschka). These joints are formed
between the uncinate processes (unci), which are crests on the superolateral regions of the vertebral bodies, and
the inferolateral surfaces of the vertebral bodies which lie superior to them. These joints play a role in the control
of cervical spine movements and also stabilize the neck.

5. • JOINTS OF THE VERTREBRAL ARCHIES: They are plane synovial joints known as
the zygapophyseal joints, often called facet joints. These joints are formed
between the superior and the inferior articular processes (zygapophyses) of
adjoining vertebrae. The articular surface of each facet joint is lined by hyaline
cartilage and each joint is enclosed by a thin, loose joint capsule (articular
capsule)
• THE CRANIOVERTREBRAL JOINTS: The craniovertebral joints as the name
suggests, form the skeletal connections between the cranium and vertebral
column.
They consist of two sets of joints;
->The atlanto-occipital joints: (‘yes’ or nodding movement joint), formed between
the atlas (C1 vertebra) and the occipital bone of the cranium
->The atlanto-axial joints: (‘no’ or rotational movement joints) formed between the
atlas and the axis (C2 vertebra). These joints are synovial joints that have no IV
discs. Their specialized design allows for a wider range of movement than in the
rest of the vertebral column.
• THE COSTOTRANSVERSE JOINTS: are synovial joints between the articular facet
on the tubercle of the rib and the transverse costal facet on the transverse
process of the vertebra of the same number. These joints are present in only
ribs 1 - 10. Ribs 11 and 12 lack tubercles and do not articulate with transverse

6. • THE SACROILIAC JOINTS: The sacroiliac joints are compound joints that
occur between the articular surfaces of the sacrum and the iliac parts of
the hip bones. Each joint is composed of an anterior synovial part
between the ear-shaped articular facets of the sacrum and ilium which
are covered by hyaline articular cartilage, and a posterior syndesmosis
between the tuberosities of the same bones. These joints have great
strength and are specialized to bear the weight of the axial skeleton and
transmit it to the hip bones and the lower limbs. Unlike most synovial
joints, the sacroiliac joints have limited mobility partly because of their
irregular, interlocking articular surfaces and also because of associated
stabilizing ligaments.

7. MOVEMENTS OF THE VERTEBRAL COLUMN
• The range of movement of vertebral column varies according to the region and the individual. The
normal range of movement possible in healthy young adults is typically reduced by 50% or more as they
age.
• The mobility of the vertebral column results primarily from the compressibility and elasticity of the IV
discs.
• The vertebral column is capable of the flexion, extension, lateral flexion and extension and rotation
(torsion).
• Bending of the vertebral column to the right or left from the neutral (erect) position is lateral flexion;
returning to the erect posture from a position of lateral flexion is lateral extension.
• The range of movement of the vertebral column is limited by the:
 Shape and orientation of the zygapophysial joints.
 Thickness, elasticity and compressibility of the IV discs.
 Resistance of the back muscles and ligaments. ( eg : the ligamental flava and posterior longitudinal
ligaments).
 tension of the joint capsules of the zygapophysial joints.
 attachment to the thoracic (rib) cage.
 Bulk of surrounding tissue
• Movements are not produced exclusively by the back muscles.
• Movements are assisted by gravity and the action of the anterolateral abdominal muscles.

8. • Movements of the vertebral column are freer in the cervical and lumbar regions than elsewhere.
• Flexion, extension, lateral flexion, and rotation of the neck are especially free because the
 IV discs, although thin relative to most other discs, are thick relative to the size of the vertebral
bodies at this level.
 articular surfaces of the zygapophysial joints are relatively and the joint planes are almost horizontal.
 joint capsules of the zygapophysial joints are loose.
 neck is relatively slender (with less surrounding soft tissue bulk compared with the trunk).

9. CURVATURES OF VERTEBRAL COLUMN
• The vertebral column in adults has four curvatures that occur in the cervical, thoracic, lumbar, and
sacral regions. Their main function is to provide a flexible and dynamic support (shock-absorbing
resilience) for the body and to protect the vertebral column from injury. The curvatures of the vertebral
column provide additional flexibility (shock-absorbing resilience), further augmenting that provided by
the IV discs.
• Thoracic kyphosis
• Sacral kyphosis
• Cervical lordosis
• Lumbar lordosis
• Primary curvatures: are retained from original fetal curve.
 As a consequence of differences in height between the anterior and posterior parts of the vertebrae, the
primary curvatures are preserved throughout life.
 Concave anteriorly
 Sacral curvatures differ in males and females; the latter (female) is less pronounced so that the coccyx
protrudes less into the pelvic outlet, making it suitable for childbirth.
Primary curvature
Secondar curvature

10. • Secondary curvatures: are developed after birth.
 These curvatures arise as a consequence of extension from the flexed fetal position.
 These are maintained primarily by differences in thickness between the anterior and posterior parts of the IV discs.
 Concave posteriorly.
 Cervical curvature becomes apparent when an infant begins to raise the head while prone and to maintain the head
erect when sitting.
 The lumbar curvature becomes more evident when an infant begins to stand and walk in an upright posture.
 The lumbar curvature is more pronounced in females and ends at the lumbosacral angle which is formed at the
junction of L5 vertebra with the sacrum.

11. VASCULATURE OF VERTEBRAL COLUMN
• Vertebrae are supplied by periosteal and equatorial branches of the major cervical and segmental
arteries and their spinal branches. Parent arteries of periosteal, equatorial, and spinal branches occur at
all levels of the vertebral column in close association with it, and include the following arteries:
• Vertebral and ascending cervical arteries in the neck (Neck).
• The major segmental arteries of the trunk:
 Posterior intercostal arteries in the thoracic region(Back).
 Subcostal and lumbar arteries in the abdomen(Abdomen) .
 Iliolumbar and lateral and medial sacral arteries in the pelvis(Pelvis and perineum)
• Periosteal and equatorial branches arise from these arteries as they cross the external
(anterolateral) surfaces of the vertebrae. Spinal branches enter the IV foramina and divide. Smaller
anterior and posterior vertebral canal branches pass to the vertebral body and vertebral arch,
respectively, and give rise to ascending and descending branches that anastomose with the spinal
canal branches of adjacent levels . Anterior vertebral canal branches send nutrient arteries
anteriorly into the vertebral bodies that supply most of the red marrow of the central vertebral
body.
• The larger branches of the spinal branches continue as terminal radicular or segmental medullary
arteries distributed to the posterior and anterior roots of the spinal nerves and their coverings and
to the spinal cord, respectively.

12. • Spinal veins form venous plexuses along the vertebral column, both
inside and outside the vertebral canal. These plexuses are the
internal vertebral venous plexuses (epidural venous plexuses) and
external vertebral venous plexuses, respectively.
• These plexuses communicate through the intervertebral foramina.
Both plexuses are densest anteriorly and posteriorly and relatively
sparse laterally. The large, tortuous Basi vertebral veins form within
the vertebral bodies. They emerge from foramina on the surfaces of
the vertebral bodies (mostly the posterior aspect) and drain into the
anterior external and especially the anterior internal vertebral
venous plexuses, which may form large longitudinal sinuses. The
intervertebral veins receive veins from the spinal cord and vertebral
venous plexuses as they accompany the spinal nerves through the
IV foramina to drain into the vertebral veins of the neck and
segmental (intercostal, lumbar, and sacral) veins of the trunk.

13. NERVES OF VERTEBRAL COLUMN
• Other than the zygapophysial joints (innervated by articular branches of the medial branches of the posterior rami, as
described with these joints), the vertebral column is innervated by (recurrent) meningeal branches of the spinal nerves.
• These small branches are the only branches to arise from the mixed spinal nerve, arising immediately after it is formed and
before its division into anterior and posterior rami or from the anterior ramus immediately after its formation.
• Two to four of these one meningeal branches arise on each side at all vertebral levels. Close to their origin, the meningeal
branches receive communicating branches from the nearby gray rami communicants. As the spinal nerves exit the IV
foramina, most of the meningeal branches runback through the foramina into the vertebral canal (hence the alternate term
recurrent meningeal nerves). However, some branches remain outside the canal and are distributed to the anterolateral
aspect of the vertebral bodies and IV discs. They also supply the periosteum and especially the anuli fbrosi and anterior
longitudinal ligament.
• Inside the vertebral canal, transverse, ascending, and descending branches distribute nerve fibers to the Following structures:
 Periosteum (covering the surface of the posterior vertebral bodies, pedicles, and laminae).
 Ligamenta fava.
 Anuli fibrosi of the posterior and posterolateral aspect of the IV discs.
 Posterior longitudinal ligament.
 Spinal dura mater.
 Blood vessels within the vertebral canal.
• Nerve fibers to the periosteum, anuli fibrosi, and ligaments supply pain receptors. Those to the anuli fibrosi and ligaments
also supply receptors for proprioception (the sense of one’s position). Sympathetic fibers to the blood vessels stimulate
vasoconstriction.

14. CONCLUSION
• The major function of the vertebral column is protection of the spinal cord; it also provides
stiffening for the body and attachment for the pectoral and pelvic girdles and many muscles. In
humans an additional function is to transmit body weight in walking and standing. It also provides
attachments to muscles, supports the trunk, protects the spinal cord and nerve roots and serves as
a site for hemopoiesis. It is also utmost important for locomotion.
• The vertebral column is utmost important for us to survive and for us to carry on with our daily
activities.

15. THANK YOU!