2. Objectives
• 1. Describe the general structure of the vertebra
• 2. Describe the structure of the atypical cervical vertebrae
• 3. Describe the structure of typical cervical vertebrae
• 4. Describe the structure of the thoracic vertebra
• 5. Describe the structure of the lumbar vertebra
• 6. Describe the structure of the sacrum
• 7. List the differences between vertebrae in different regions of the
vertebral column
3. Vertebral Column
• Consists of 31 vertebrae and the
intervening discs
• It appears as straight line
anteroposteriorly, and with multiple
curves laterally
• According to shape and location,
vertebrae can be divided into:
Cervical
Thoracic
Lumbar
Sacral
• Primary vs Secondary curve
• Spine abnormalities
4.
5. •Vertebral Column
•7 C, 12 T, 5 L, 5 S
(Fused as Sacrum),
4 coccygeal
•Primary Curves
•Secondary Curves
6. Secondary Curves (Lateral view)
1.Primary curves
- present at birth due to the shape of the vertebral
bodies.
-thoracic and sacral,
-both are concave forwards.
2. Secondary curves
-postural
-mainly due to the shape of the intervertebral
disc.
-The secondary or compensatory curves are
cervical and lumbar,
-both are convex forwards.
-The cervical curve appears during four to five
months after birth when the infant starts supporting
its head:
-The lumbar curve appears during twelve to
eighteen months when the child assurnes the upright
posture
7. Lateral curve(coronal plane)
There is slight lateral curve in the thoracic region with its concavity towards the
left. It is possible due to the greater use of the right upper limb and the pressure of
the aorta.
The curvatures add to the elasticity of the spine, and the number of curves gives it
a higher resistance to weight than would be afforded by a single curve.
8. Vertebral Column
• General structure of vertebra
:
• Body
• Pedicle
• Lamina
• Spine
• Transverse process
• Vertebral foramen
• Vertebral notch
• Superior articulating process
• Inferior articulating process
9.
10. Typical Vertebrae
Body
• Superior and inferior surfaces of
body (plateaus)
• Thickened around the rim, location
of epiphyseal plates
• Cartilaginous end-plates
Vertebral Arch
• Pedicles, Laminae
• Transverse Processes
• Spinous Process
• Facets – superior articular and
inferior articular
19. • Intervertebal Discs
•Intervertebral Discs
•Fibrocartilaginous
joints
•Increase in size from C
to L (3mm to 9 mm)
•Make up 20-30% of
length of column
21. Discs
•Outer rim of fibrocartilage called the anulus fibrosus (attaches
to cartilaginous end plate)
•Connects vertebral bodies in a fibrocartilaginous joint (no
capsule, little motion)
•Anulus encloses a central mass called the nucleus pulposus
•About 80-90% water, less with increased age
•Contains a mucopolysaccharide matrix
•Changes shape, releases and absorbs water.
•Neither blood vessels or nerves penetrate nucleus
22. Discs
•Structure deforms when pressure is put on vertebral column as
in weight bearing
•Acts as a shock absorber
•Annulus totally encloses the nucleus and keeps it under
constant pressure
•With increased age, the H2O content decreases and the
nucleus becomes more fibro cartilaginous, therefore less easily
deformable and more easily damaged
23. Discs
•Nucleus, when under extreme pressure, can herniate or
extrude from the disc in a posterior or posterior-lateral
direction
•Usually occurs in cervical or lumbar region
•Nucleus can put pressure on spinal nerve causing referred
symptoms (motor and sensory)
•Can cause pressure on cord itself if true posterior
24. TypicalCervical Vertebrae
Body
-small and broader from side to side than from
before backwards.
- superior surface is concave transversely with
upward projecting lips on each side. The
anterior border of this surface may be
bevelled.
- inferior surface is convex from side to side
and concave from before backwards.
The lateral borders are bevelled and form
synovial joints with the projecting lips of the
next lower vertebra.
The anterior border projects downwards and
may hide the intervertebral disc.
The anterior and posterior surfaces resemble
those of other vertebrae .
25. • Vertebral Foramen
- larger than the body.
-triangular in shape
Vertebral Arch
1 The pedicles-directed backwards and laterally. The superior and inferior vertebral
notches are of equal size.
2 The laminae are relatively long and narrow, being thinner above than below.
3 The superior and inferior articular processes form articular pillars which project
laterally at the junction of pedicle and the lamina. The superior articular facets are
flat. They are directed backwards and upwards. The inferior articular facets are also
flat but are directed forwards and downwards.
4 The transverse processes are pierced by foramina transversaria. Each process has
anterior and posterior roots which end in tubercles joined by the costotransverse
bar.. The anterior tubercle of the sixth cervical vertebra is large and is called the
carotid tubercle because the common carotid artery can be compressed against it.
5 The spine is short and bifid. The notch is fitled up by the ligamentum nuchae
26.
27. Cervical Vertebrae
• 1st cervical vertebra(Atlas)
• No body
• No spine
• On the anterior arch(short) - an anterior tubercle (tuberculum
anterius) and a fossa of the tooth (fovea dentis) ;
• on the posterior arch(long) - posterior tubercle (tuberculum
posterius) ,fossa of the vertebral artery (sulci arteriae
vertebrales) .
• The anterior and posterior arches are connected to each other
by means of lateral masses (massae laterales) . on the lateral
masses on both sides are located:
-the superior articular fossa - elliptical
- the linferior articular fossa - flat and round.
- the transverse processes with a transverse foramen .
2nd cervical vertebra (Axis)
• Looks like typical vertebra It has odontoid process (Dens)
• which has the articular surfaces anteriorly and posteriorly; the body
(corpus vertebrae) ; an arch of vertebra (arcus vertebrae) where
distinguish between transverse processes (processus transversus) ,
having a transverse foramin; each side has upper articular surface
(facies articularis superior) and the lower articular surface (facies
articularis inferior) .
28.
29.
30.
31.
32. Typical Cervical Vertebrae
Characterized by the general
structure of vertebra but
each has a bifid spine
•7th cervical vertebra:
Characterized by general
structure of vertebra but it
has NO bifid spine
37. Lumbar Vertebra
• Body
Kidney-shaped body(wider from side to side
than before back wards)
-hight greater anteriorly than
posteriorly(contributes to farward convexity)
No impression for rib articulation
vertebral foramen
Triangular
Larger than thoracic,smaller than cervical
Pedicles
Short and strong
Project farward from upper part of the body
Inferior vertebral notch deeper than superior
Laminae
Short, thick,broad
spine
• Short, thick, directed back wards and slightly
downwards
38. transaerse processes
thin and tapering, and
directed laterally and slightly backwards.
Develop from the costal element (homologous with the
ribs in the thoracic region).
posteroinferior aspect of the root of each transverse
process
is marked by a small, rough elevation, the accessory
process,.
The length - increases from vertebra L1 to L3 then, it
decreases
superior articular processes
lie apart than the inferior.
- concave facet facing medially and backwards.
- posterior border is marked by a rough elevation, the
mammillary Process.
inferior articular processes
lie nearer to each other than the superior.
convex facet facing laterally and forwards.
39.
40. Fifth Lumber Vertebra
a.The transverse processes - thick, short and
pyramidal in shape.
Their base is attached to the whole thickness of
the pedicle and encroaches on the side of the
body .
b. The distance between the inferior articular
processes is equal to or more than the distance
between the superior articular processes.
c.The spine is small, short and rounded at the tip.
d. The body is the largest of all lumbar vertebrae.
sharp lumbosacral angle and is 120" in an adult.
f. pedicles- directed backwards and laterally.
g.superior articular facets look more backwards
than medially
the inferior articular facets look more forwards
than laterally(as compared to other lumbar
vertebrae )
43. The sacrum
• a large, flattened, triangular bone formed by the fusion of five sacral vertebrae.
• forms the posterosuperior part of the bony pelvis,
• articulating on either side with the corresponding hip bone at the sacroiliac joint.
• The upper part of the sacrum is massive because it supports the body weight and
transmits it to the hip bones. The lower part is free from weight.
Base
Apex
Pelvic surface – smooth,concave
Dorsal suface – irregular ,convex
Right and left surfaces – irregular ,partly articular
divided by rows of foramina into:
• a. Median portion, traversed by the sacral canal.
• b. A pair of lateral masses formed by fusion of the
transverse processes posteriorly, and of the costal
elements anteriorly.
44. Base
• directed upwards and forwards.
• formed by the upper surface of the first sacral vertebra
• features of a typical vertebra in a modified form
1. body-lumbar in type.
- It articulates with vertebra L5 at the lumbosacral joint.
-The projecting anterior margin is called the sacral promontory.
-The surface slopes forwards at an angle of 30 degrees.
2.vertebral foramen lies behind the body, and leads into the sacral
canal.
-triangular in shape.
3. Pedicles - short and are directed backwards and laterally.
4 .laminae -oblique.
5. Spine - forms the first spinous tubercle.
6. superior articular processes – upwards,
facets - directed backwards and medially.
7. transverse processes are highly modified. Each process is massive
and fused with the corresponding costal element to form the upper
part of the lateral mass of the sacrum
• The base of the lateral mass, forms a broad sloping surface
spreading fan wise from the side of the body. It is called the ala of
the sacrum. The ala is subdivided into a smooth medial part and a
rough lateral part.
45. Apex
• formed by the inferior surface of the body of the fifth sacral vertebra.
• bears an oval facet for articulation with the coccyx.
Pelvic surface
• concave,directed downwards and forwards.
• median area marked by four transverse ridges, which indicate the lines
of fusion of 5 sacral vertebrae bodies
• ridges end on four pelvic sacral foramina, which communicate with the
sacral canal through the intervertebral foramina. The lateral part formed
by transverse processes .
Dorsal surface
• rough, irregular and convex - directed backwards and upwards.
• In the median plane - median sacral crest with 3 to 4 spinous tubercles
• inverted U-shaped gap in the posterior wall of the sacral canal- sacral
hiatus.
• Lateral to the median crest - formed by the fused laminae.
• Lateral to the laminae(intermediate crest) - four articular tubercles.
The inferior articular processes of the fifth sacral vertebra are free and
form sacral cornua.
• Lateral to articular tubercles - four dorsal sacral foramina
• Lateral to the foramina, there is the lateral sacral crest with transverse
tubercles,
46. Lateral surface
• formed by the fused transverse processes and
the costal elements of the sacral vertebrae.
• wide above and narrow below.
• upper wider part bears L-shaped auricular
surface anteriorly . It articulates with the
• auricular surface of the hip bone at the
sacroiliac joint.
Sacral canal
• formed by the sacral vertebral foramina, and
is
• triangular.
• The upper end directed upwards ,inferiorly
the canal opens at the sacral hiatus, and
laterally it communicates through the
intervertebral foramina with the pelvic and
dorsal sacral foramina.
47.
48. coccyx
• small triangular bone formed by fusion of four
rudimentary coccygeal vertebrae, which progressively
diminish in size from above downwards.
• The base is directed downwards and forwards, making
a continuous curve with the sacrum.
• The first coccygeal piece is the largest, commonly
found as a separate vertebra. The upper surface of its
body forms the base of the coccyx, which articulates
with the apex of the sacrum.
• Projecting upwards from the posterolateral side of the
base are coccygeal cornua, which represent the
pedicles and superior articularprocesses.
• They articulate with the sacral cornua and are
connected to them by intercornual ligaments.
• Rudimentary transrserse processes project laterally
and slightly upwards from the side of the base.
• The second, third and fourth coccygeal vertebrae are
mere bony nodules which diminish successively in size
and are usually fused together.
49. Ligaments of the Spine
• Anterior longitudinal
• Posterior longitudinal
• Supraspinous
• Interspinous
• Ligamentum flavum
50.
51. Ligaments of the Spine
• Tectorial membrane
Interspinous ligaments
• Supraspinous ligament
• Ligamentum flavum
52. Atlanto-Occipital Joint
• Two concave superior facets of atlas articulate with two convex
surfaces of occipital condyles of the skull
• Supported by major ligaments:
1- Ant. Atlanto-Occipital,
2- Tectorial Membrane,
3- Post. A-O
• Small saddle joint
• Very limited motion
• nodding type motions in all directions.
53.
54. Atlanto-Axial Joint
• Atlas and Axis
• Pivot
• Two convex superior facets of axis with two concave inferior facets of
the atlas
• Atlas also posses a facet on the internal surface of the anterior arch
which articulates with the dens of the axis
• Major ligaments from spine support – alar ligament and cruciate
ligament
Cruciate ligament
Superior longitudinal
Inferior longitudinal
Transverse
65. Sternum
• Sternum — unpaired flat bone, (like a short sword)has the handle of the sternum
(manubrium sterni); the body of the sternum (corpus sterni) ; xiphoid process
(processus xiphoideus) ; sternal angle (angulus sterni) (corresponds to the level of
attachment of the 2nd rib); jugular notch (incisura jugularis) ; clavicular notch (incisura
clavicularis) ;articular notches for seven pairs of ribs (incisurae costales) .
• Ribs (costae) — 12 pairs: 7 pairs of upper ribs (I–VII), connected- those with a sternum
are called true ribs ;
• 3 pairs of lower ribs (VIII, IX, X) are not connected to the sternum, but are connected to
the overlying ribs and are called-the lower false ribs (costae spuriae);
• 2 the last pairs (XI, XII) with the overlying ribs do not connect, but end freely in the
lateral wall of the abdominal cavity, are very mobile, which is why they are called
oscillating ribs (costae fluctuantes).
• On the rib , the bony part of the rib (oscostale) and the costal cartilage (cartilago
costalis) are distinguished; the rib has an outer and inner surface.
• The bone part has a rib head (caput costae) ( connection with vertebral bodies), a rib
neck (collum costae) ; tubercle of the rib (tuberculum costae) (for connection with the
transverse process of the vertebra, absent in XI, XII pairs of ribs); angle of the rib
(angulus costae) (in the first pair of ribs, it coincides with the tubercle of the rib); costal
groove (sulcus costae) (on the inner surface of the lower edge) for vessels and nerve.
66. • The head of the ribs has a scallop rib head (crista capitis costae), which is absent
in I, XI and XII pairs of ribs; on the neck rib a cervical rib crest (crista colli costae)
(except for the presentation of XI and XII pairs of ribs).
• The first rib has an upper and lower surface. On the upper surface, there is a
tubercle of the anterior stair muscle (tuberculum musculi scaleni anterioris) , a
sulcus of the subclavian vein (sulcus venae subclaviae) -anteriorly from the
tubercle; a sulcus of the subclavian artery (sulcus arteriae subclaviae) -posteriorly
from the tubercle.
Location :
• 1) sternum-the handle of the sternum is located up, the angle of the
sternum is forward;
• 2) ribs — the head of the rib is located posteriorly, the sharp edge is directed
downwards, the convex (outer) surface of the rib is outward;
• 3) the first rib — the head of the rib is directed posteriorly, the tubercle of the
anterior stair muscle is upward.
