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THE VERTEBRAL COLUMN AND THE VERTEBRAL CANAL
THE VERTEBRAL COLUMN
• The central bony pillar of the body
• Functions:1. To support the skull, pectoral girdle, upper limbs,
thoracic cage and the pelvic girdle
2. To protect the spinal cord, roots of the spinal nerves, ad the meninges (coverings) located in the vertebral cavity
3. For posture and locomotion
4. To support the body
The Vertebral Column• COMPOSITION: 33 vertebrae• The regions in the vertebral column are as follows:
Cervical (7)
Lumbar (5)
Sacral (5)
Coccygeal (4)
Thoracic (12)
Fused to form the sacrum
Last 3 fused to form the coccyx
The Vertebral Column
• Flexible structure due to – Segmented– Made up of vertebrae, joints, intervertebral
disk
• Stabilized by ligaments, muscles and the intervertebral discs
CURVES
• SAGITTAL PLANE– Due to upright posture
and weight-bearing musculature
• CORONAL PLANE– Due to the use of the
upper limbs
Curves in the Sagittal Plane
In the fetus, the curve is one continuous
anterior cavity.
At birth, the lumbosacral angle appears.
Curves in the Sagittal Plane
At 3-4 months, when the infant starts to raise his head,
the cervical part becomes concave.
Curves in the Sagittal Plane
At around 1 year old, the child begins to stand upright.
The lumbar part becomes concave posteriorly.
The secondary curves are due to the shape of the intervertebral disks.
Curves in the Sagittal Plane
In an adult, the regional curves are identifiable: cervical (posterior concavity) thoracic (posterior convexity) lumbar (posterior concavity) sacral (posterior convexity – to preserve the center of gravity)
Curves in the Sagittal Plane
Primary Curves
Secondary Curves
Curves in the Coronal Plane
Late Childhood:
Minor lateral curves (thoracic area) – NORMAL
Compensatory curves above and below the lateral curve.
PARTS OF A VERTEBRA
• GENERAL DESIGN
Vertebral Body
Vertebral Arch
Anterior
Posterior
PARTS OF A VERTEBRA
• GENERAL DESIGN
Pedicle
Laminae – flattened
Vertebral foramen – enclosed by the arch and the body - where the spinal cord and its coverings are
VERTEBRAL CANAL – formed by the succession of foramina
Anterior
Posterior
PARTS OF A VERTEBRA
• GENERAL DESIGN
Spinous Process
Transverse processes (2)
Anterior
Processes (7)
Articular process (Superior - 2)
Articular process (Inferior - 2)
AnteriorPosterior
Superior vertebral notch
Posterior
Inferior vertebral notch
Intervertebral Foramen
Transmits the spinal nerves and blood vessels
THE CERVICAL VERTEBRAEParts Cervical
A. BODY •Small, •broad from side to side
B. VERTEBRAL ARCH with Vertebral Canal/ Foramen
Large, triangular
D. PROCESSES
1. spinous Small and bifid
2. transverse Has a transverse foramen (vertebral artery and vein)
3. Superior Articular Facets face upward and backward
4. Inferior Articular Facets face downward and forward
THE CERVICAL VERTEBRAE Parts Typical Cervical
Vertebrae
(C2-C7)
C1-Atlas
(Atypical)
C2- Axis
(Atypical)
C7
(Atypical ?)
A. BODY •Small, •broad from side to side
•Absent Body of C1 fused with body of C2 to form the odontoid process
B. VERTEBRAL ARCH with
Vertebral Canal/ Foramen
Large, triangular Has an anterior and posterior arch
Each with a tubercle and a lateral mass
D. PROCESSES
1. spinous Small and bifid Absent Not bifid, Long (vertebral prominens)
2. transverse Has a transverse foramen
(vertebral art. & vein)
3. Superior
Articular
Facets face upward and backward
Kidney-shaped facet is large to articulate with the occipital condyle
4. Inferior
Articular
Facets face downward and forward
?
?
Parts Thoracic
A. BODY •Medium – sized, •heart-shaped•Has costal facets on sides to articulate with the head of the ribs
B. VERTEBRAL ARCH with Vertebral Canal/ Foramen
Small, circular
D. PROCESSES
1. spinous Long, inclined forward
2. transverse Has costal facets to articulate with the tubercle of the ribs
3. Superior Articular Facets that face backward and laterally
4. Inferior Articular Facets that face forward and medially
THE THORACIC VERTEBRAE
Parts Thoracic
A. BODY •Medium – sized, •heart-shaped•Has costal facets on sides to articulate with the head of the ribs
B. VERTEBRAL ARCH with Vertebral Canal/ Foramen
Small, circular
D. PROCESSES
1. spinous Long, inclined forward
2. transverse Has costal facets to articulate with the tubercle of the ribs
3. Superior Articular Facets that face backward and laterally
4. Inferior Articular Facets that face forward and medially
THE THORACIC VERTEBRAE
THE THORACIC VERTEBRAE Parts Typical Thoracic
Vertebrae
(T5-T8)
Atypical Thoracic Vertebrae
(T1 to T4)With features of
cervical vertebrae
Atypical Thoracic Vertebrae
(T9 to T12)
With tubercles similar to lumbar vertebrae
A. BODY •Medium – sized, •heart-shaped•Has costal facets on sides to articulate with the head of the ribs
•T1 – has a complete ocstal facet on its body and a demifacet on its inferior edge
B. VERTEBRAL ARCH with
Vertebral Canal/ Foramen
Small, circular
D. PROCESSES
1. spinous Long, inclined forward T1 – long, horizontal spine
2. transverse Has costal facets to articulate with the tubercle of the ribs
T11 – T12
No costal facets to articulate with ribs
3. Superior
Articular
4. Inferior
Articular
T12 – facets face laterally
Parts Lumbar
A. BODY Large,
Kidney-shaped
B. VERTEBRAL ARCH with Vertebral Canal/ Foramen
•triangular•Pedicles are strong and directed backwards.•Laminae are thick.
D. PROCESSES
1. spinous Short, flat quadrangular, projects backward
2. transverse Long, slender,
no costal facets
3. Superior Articular Faces medially
No facets for ribs
4. Inferior Articular Faces laterally
THE LUMBAR VERTEBRAE
PECULIAR FEATURES OF THE VERTEBRAE IN EACH REGION
Parts Cervical Thoracic Lumbar
A. BODY •Small, •broad from side to side
•Medium – sized, •heart-shaped•Has costal facets on sides to articulate with the head of the ribs
Large,
Kidney-shaped
B. VERTEBRAL ARCH with Vertebral Canal/ Foramen
Large, triangular Small, circular •triangular•Pedicles are strong and directed backwards.•Laminae are thick.
D. PROCESSES
1. spinous Small and bifid Long, inclined forward Short, flat quadrangular projects backward
2. transverse Has a transverse foramen (vertebral artery and vein)
Has costal facets to articulate with the tubercle of the ribs
Long, slender, no costal facets
3. Superior Articular Facets face upward and backward
Facets that face backward and laterally
Faces medially
No facets for ribs
4. Inferior Articular Facets face downward and forward
Facets that face forward and medially
Faces laterally
SACRAL BONE• 5 rudimentary vertebrae fused to form a
wedge-shaped bone concaved anteriorly
• Articulations*
Promontory
Vertebral foramina forms the sacral canal, contains the subarachnoid space
Laminae fail to meet at the midline
(sacral hiatus)
Where sacral nerves pass throughSacral canal•Sacral n.•Coccygeal n.•Filum terminale•Fibrofatty material
THE COCCYX
The first coccygeal bone is usuallyFused or incompletely fused with the Second coccygeal bone.
LIGAMENTS• Anterior Longitudinal Ligament
Strong, broad fibrous band
Covers and connects the anterior aspects fo the verterbral bodies and intervertebral discs
From the anterior tubercle of C1 and the occipital bone of the skull anterior to the foramen magnum to the sacrum
pelvic surface of the sacrum to the Prevents hyperextension of the vertebral column
• Posterior Longitudinal Ligament
Weaker, narrower band
Runs along the posterior bodies of the vertebral bodies within the vertebral canal
From C2 to the sacrum
Prevents hyperextension of the vertebral colmn
LIGAMENTS• Anterior Longitudinal Ligament
Strong, broad fibrous band
Covers and connects the anterior aspects fo the verterbral bodies and intervertebral discs
From the anterior tubercle of C1 and the occipital bone of the skull anterior to the foramen magnum to the sacrum
pelvic surface of the sacrum to the Prevents hyperextension of the vertebral column
LIGAMENTS• Posterior Longitudinal
Ligament
Weaker, narrower band
Runs along the posterior bodies of the vertebral bodies within the vertebral canal
From C2 to the sacrum
Prevents hyperextension of the vertebral colmn
THE INTERVERTEBRAL DISC
• LOCATION– ¼ the entire length of the vertebra– Thickest at the cervical and lumbar regions– Shock absorbers
– In between vertebrae EXCEPT• Between C1 and C2• In the sacrum• In the coccyx
First disc is between C2 and C3.Last functional disc is between L5 and S1.
Total= 18
Annulus Fibrosus fibrocartilage and collagen fibers
Nucleus Pulposus In children: gelatinous, with large amount of water little amount of cells
In adults: replaced by collagen fibers discs becomes thin and less elastic
cannot distinguish it from annulus fibrosus
HERNIATION OF THE INTERVERTEBRAL DISC
• A sudden increase in the compression load of the vertebra causes the semifluid nucleus pulposus to become more flattened.
• At times the outward thrust is too great, the annulus fibrosus ruptures and the nucleus pulposus herniates and protrudes into the vertebral canal (compressing the spinal cord, roots or nerves).
HERNIATION OF THE INTERVERTEBRAL DISC
• A sudden increase in the compression load of the vertebra causes the semifluid nucleus pulposus to become more flattened.
• At times the outward thrust is too great, the annulus fibrosus ruptures and the nucleus pulposus herniates and protrudes into the vertebral canal (compressing the spinal cord, roots or nerves).
ATLANTO-OCCIPITAL JOINTSynovial Joint (condyloid)
• ARTICULATING BONES
Occipitalcondyles
MOVEMENTS: flexion, extension, lateral flexion NO ROTATION!
ATLANTO-AXIAL JOINT
• JOINT CLASSIFICATION• Synovial Joint (Pivot Joint)
• 3 synovial joints:– between the odontoid
process and the anterior arch of the atlas
– 2 joints between the lateral masses of the bones
ATLANTO-AXIAL JOINT
• JOINT CLASSIFICATION:• Synovial Joint (Pivot Joint)
• 3 synovial joints:– between the odontoid
process and the anterior arch of the atlas
– 2 joints between the lateral masses of the bones
MOVEMENTS: extensive rotation of the atlas and of the head.
LUMBAR TAP
• A procedure to withdraw cerebrospinal fluid for examination
• For clinical diagnosis• Introduce drugs• Remove “excess
spinal fuid” (headache)
The patient lies on his side with hisVertebrae well flexed.
This widens the space between the adjoining laminae.
The level of t he fourth lumbar spine is determined by drawing an imaginary line joining the highest points of the iliac crest. the vertebrae
The lumbar puncture needle is passed into the vertebral canalAbove or below the fourth lumbar spine.
Structures:1. Skin2. Superficial fascia3. Supraspinous ligament4. Interspinous ligament5. Ligamentum flavum6. Areolar tissue containing the internal vertebral venous plexus in the epidural space7. Dura matter8. Arachnoid matter9. Subarachnoid space
SPONDYLOLYSIS
• Spinous process, laminae and inferior articular process
separate from
the body pedicles and the superior articular process
• NO ANTERIOR DISPLACEMENT
SPONDYLOLISTHESIS
• Spinous process, laminae and inferior articular process
separate from
the body pedicles and the superior articular process
• THERE IS ANTERIOR DISPLACEMENT
SPONDYLOLISTHESIS
• The body of a lower lumbar vertebra (usually of L5) moves forward to the body of the vertebra below and carries with it the whole upper portion of the vertebral column
• The nerve roots may be compressed.
THE VERTEBRAL COLUMN AND THE VERTEBRAL CANAL