Vertebral Column Flashcards
How many bones make up the vertebral column?
32-34
Describe the gross functions of the vertebral column.
Centre of gravity Attachment for bones - Above bears and supports head - Centrally ribs/scapula, indirect support for upper limbs - Below articulates with the hip bones, together bear most of the body weight Attachment for trunk muscle Protection of the spinal cord Segmental innervation of the body
Describe curvature of the vertebral column in the foetus
Anterior concave
Primary curvature throughout whole column
Describe kyphosis
Exaggerated anterior curvature
Describe curvature of the vertebral column in a young adult
Sinusoidal presentation to give great flexibility and resistance.
Two anterior and two posterior flexion
Secondary in cervical and lumbar regions
Primary in thoracic, sacral and coccyx
Describe curvature of the vertebral column in old age.
Secondary curvature disappears
How many vertebrae are separable from their neighbours?
24
What vertebrae are fused?
Sacrum (5)
Coccyx (4)
Describe the vertebral body
Usually the largest part and mainly weight bearing.
Size increases from top down
Linked adjacently by intervertebral discs
Arrangement repeated from C2/3 to L5/S1
Describe the structure of the vertebral arch
Spinous process in the midline
Transverse process laterally
Pedicle between body and transverse process
Lamina between transverse and sinous process
Articular processes at junction of lamina and pedicle, one superior and one inferior on both sides.
Describe the articular facets on the vertebral arch
One superior and one inferior on each side
Cartilage-lined to form synovial joints between adjacent vertebrae.
Strengthened by the ligamentum flavum.
What makes up the intervertebral foramen?
Superior and inferior notch of each pedicle
What class of joint are the vertebrae?
Secondary cartilagenous joints: symphyses
Describe changes in the intervertebral discs throughout the spine.
Increase in size from superior to inferior
Wedge shaped in the lumbar and thoracic levels, thickets anteriorly here
Approximately what percentage of the height of the vertebral column does intervertebral discs account for?
25%
What are the two regions of intervertebral discs?
Central nucleus pulposus and peripheral annulus fibrosis
What is the origin of the nucleus pulposus?
Embryonic notochord
Describe the nucleus pulposus
Jelly-like with high osmotic pressure: water reservoir
Changes size with age and position
Describe a ‘slipped disc’
When the nucleolus pulposus herniates through the annulus fibrosis, can lead to degradation. Largely does so posteriolaterally.
Describe marginal osteophytosis
A bony projection which develops on the exterior of the joint, most commonly secondary to osteoarthritis.
This is because load stresses on the disc alter as its size decreases.
Increased stress on the facet joints leads to osteoarthritis.
Decreasing disc height can lead to congestion of the intervertebral foramen and compression of the segmental nerves.
Describe spondylosis deformans (senile ankylosis)
Progressive degeneration of the annulus, causing increasing osteophytosis at the disc space margins. Disc space is largely preserved.
Usually seen in the thoracocolumnar spine in the over-50’s.
Describe the facet joint
Set of synovial plane joints between the articular processes of two adjacent vertebrae.
Describe the anterior longitudinal ligament
Ends at the sacrum
Starts narrow then broadens, largely flat.
Strongest
Firmly attached to the periosteum of the vertebral bodies and free over the vertebral discs
Describe the posterior longitudinal ligament
Thin at the bottom and thick at the top.
Serrated margins
Basivertebral veins separate it from the vertebral bodies, explaining why herniation mainly occurs at this point.
Describe the ligamentum nuchae
Proximal attachment at the occipital protuberance.
Continuous with the supraspinous ligament.
Maintains secondary curvature.
Describe the supraspinous ligament
Join tips of the adjacent spinous process
Strong bands of white fibrous tissue
Lax in the extende dspine
In flexion are drawn taut to mechanically support the spine.
Describe the ligamentum flavum
Yellow in colour due to high content of elastic fibres.
Joint laminae of adjacent vertebrae
Attached to the front of the upper lamina and back of the lower lamina
Stretched by flexion of the spine
Describe the interspinous ligament
Relatively weak sheets of fibrous tissue
Unites spinous processes along adjacent borders
Only well developed in the lumbar region
Fuse with supraspinatous ligament
What are the distinguishing features of the cervical spine?
Smallest Bifid spinous process Oval transverse foramen Vertebral artery through all except C7 (has accessory vertebral veins) Large vertebral foramen
What are the distinguishing features of the thoracic spine?
Increase in size from top downwards
Facets on the side of the body
Demi-facets for articulating with the ribs
Facets on transverse process (not T11/12) to articulate with tubercle of rib
Small and circular vertebral foramen
What are the distinguishing features of the lumbar spine?
Largest of the discrete vertebrae
No costal facets
Triangular and small vertebral foramina
Spinous process not bifid
Describe the atlas vertebra.
C1 Articulates with the skull Forms the atlantooccipital and atlantoaxial joints. No body or spinous process Widest cervical vertebra Body fixed within the axis
Describe the axis vertebra.
C2 Strongest cervical vertebra 3 main features - odontoid process (dens) - rugged lateral mass - large spinous process Dens prevents horizontal displacement of the atlas
Describe a hangman’s fracture
Hanging causes the dens to fracture, atlantoaxial joint dislocates, compressing the spinal cord and causing death.
What injuries is the cervical spine particularly susceptable to?
Whiplash
Sports injuries e.g. in a scrum
What injury is the lumbar spine particularly susceptable to?
Herniation at L4/5 or L5/S1
What is the cause of scoliosis?
Unbalanced muscle tone
What is lordosis?
Excessive secondary curvature
