anatomy of vertebra

1. SKELETAL ANATOMY OF VERTEBRAE
1

2. ANATOMY OF VERTEBRAL
COLUMN
Vertebral column: 33 vertebrae divided into five sections
• Seven cervical
• Twelve thoracic
• Five lumbar
• Five sacral
• Four coccygeal
 Vertebral body increases in size from cranial to caudal.

4. • The thoracic and sacral segments maintain
kyphotic postures found in utero-
attachment points for the rib cage and
pelvic girdle.
• The cervical and lumbar segments
develop lordosis as erect posture is
acquired.

5. TYPICAL VERTEBRA

6. TYPICAL VERTEBRA
• Anterior body and a posterior arch - enclose
the vertebral canal or foramen for spinal
cord.
• The neural arch - two cylindrical pedicles
laterally and two flattened laminae posteriorly
which unite to form the spinous process.
• To either side of the arch - transverse process
and superior and inferior articular processes -
articulate with adjacent vertebrae to form
synovial joints.

7. TYPICAL VERTEBRA
• Spinous process: Posteriorly and inferiorly
from junction of the two laminae , it’s a site
for muscle and ligament attachment
• Transverse process: Posterolaterally, from the
junction of the pedicle and lamina; site for
articulation with ribs in the thoracic region
• Superior and inferior articular processes:
articulate with the inferior and superior
articular processes, respectively, of adjacent
vertebrae

8. TYPICAL VERTEBRA
• Articular processes: Accounts for the degree
of flexion, extension, or rotation possible in
each segment of the vertebral column
• Spinous and transverse processes: Levers for
the numerous muscles attached to them
The length of vertebral column averages 72 cm
in men and 7 to 10 cm less in women

9. • Total 6 joints
The joints between the neural arches
zygapophyseal joints or facet joints.
 Inferior articular process of one vertebra and the
superior articular process of the vertebra
immediately caudal.
 Synovial joints with surfaces covered by
articular cartilage, a synovial membrane, and
a joint capsule enclosing them.
 Four synovial joints (two above and two
below)

10. INTERVERTEBRAL FORAMINA

11. CERVICAL VERTEBRAE
Vertebral body:
• short in height,
• square shaped when viewed from
above
• concave superior surface and a
convex inferior surface
Spinous process is short and bifid
Vertebral foramen is triangular and large

12. ATYPICAL CERVICAL VERTEBRAE
Atlas (C1)
Axis (C2)
Vertebrae prominens (C7)

13. THORACIC VERTEBRAE
Vertebral body:
• two partial facets on each side of
the vertebral body,
• superior costal facets-head of its own rib
• inferior costal facets - head of the rib below
Transverse costal facet
Vertebral foramen is CIRCULAR

14. LUMBAR VERTEBRAE
Vertebral body:
• CYLINDRICAL
Vertebral foramen is TRIANGULAR
Transverse processes: Thin and long
Exception: Vertebra L5, which are
massive and cone-shaped for the
attachment of iliolumbar ligaments to
connect the transverse processes to the
pelvic bones

15. SACRUM
• Single bone : five fused sacral
vertebrae.
• Triangular,
• Apex pointed inferiorly, and curved
• Concave anterior surface
• Convex posteriorly

16. SACRUM
• Two large L-shaped facets, one on
each lateral surface, for articulation
with the pelvic bones
• The posterior surface of the sacrum
has four pairs of posterior sacral
foramina
• Anterior surface has four pairs of
anterior sacral foramina: S1 to S4 spinal
nerves.
• Sacral promontory: anterior upper
margin of first sacral vertebra- forms
posterior margin of pelvis

17. SACRUM

18. SACRAL CANAL CONTENTS
• Anterior and posterior roots of sacral and coccygeal spinal nerves
• Filum terminale
• Fibrofatty material
• Lower part of subarachnoid space down as far as lower border of
second sacral vertebra.

19. COCCYX
• Small triangular bone - articulates
with the inferior end of the sacrum
• Represents three to four fused
coccygeal vertebrae .
• Characterized by its small size
and by the absence of vertebral
arches and therefore a vertebral
canal.

20. VARIATIONS IN THE VERTEBRAE
• C7 may possess a cervical rib
• Thoracic vertebrae may be increased in number by addition of the L1
vertebra which may have a rib
• L5 may be incorporated into the sacrum
• S1 may remain partially or completely separate from sacrum and
resemble a 6th lumbar vertebra
• Coccyx which consists of four fused vertebra may have 3 or 5 vertebrae

21. POSTERIOR SPACES BETWEEN VERTEBRAL ARCHES
• In most regions the laminae and spinous processes of adjacent vertebrae
overlap to form a complete bony dorsal wall for the vertebral canal.
• In the lumbar region, large gaps exist between the posterior components
of adjacent vertebral arches.
• Become increasingly wide from vertebra L1 to vertebra L5.
• The spaces can be widened further by flexion of the vertebral column.
• Allow relatively easy access to the vertebral canal for clinical
procedures.

22. THANK YOU