Vertebral Column Flashcards
What forms the intervertebral foramen? What passes through this?
-Superior & inferior vertebral notches of adjacent vertebrae & intervertebral disc which the spinal nerve passes through
What are the variations of cervical vertebrae?
- Body small with elevated uncus laterally
- Transverse process & pedicle
- Transverse foramina
- Spinous process is bifid
- Articular facets superior direction superoposteriorly and inferior direction infer-anteriorly
What passes through the transverse foramen?
-Vertebral artery and vein to/from the brain, DO NOT pass through C7
Describe the different severities of a dislocated cervical vertebrae?
(A) flexion sprain (B) 25% subluxation (C) 50% subluxation (D) Complete dislocation 'facet jumping' Vertebral foramen relatively wide so subluxation may not compress spinal cord
Which spinal vertebrae are prone to dislocation?
Cervical as relatively flat articular facets
Describe the Atlas
- C1
- No spinous process or body
- Anterior & posterior arches each with a tubercle and lateral mass
- Medial surface of lateral mass has a tubercle for the transverse ligament which holds in place the dens of the axis
Describe the Axis
- C2
- 2 large flat surfaces (Superior articular facets which the atlas rotates)
- Dens or Odontoid process
- Held in position by transverse ligament of Atlas prevents horizontal displacement of Atlas
Describe a fracture of the Dens
- Less dense so prone to fracture
- Caused by hyperextension or hyperflexion
- Spinal cord not usually affected
- 30-50% result in non-union
- Atlantoaxial arthrodesis using bone graft from iliac crest
Describe the features of the thoracic vertebrae
- Heart shaped body with superior & inferior costal demi-facets for articulation with head of rib
- Long poster-inferiorly extending spinous process
- Transverse process- costal facet for articulation with tubercle of rib
- Articular facets
What does the head of the rib articulate with?
superior & inferior costal demi-facets
What does the tubercle of the rib articulate with?
Transverse process
Which rib articulates with the superior demi-facet?
Head of the rib with the same number as the vertbrae
Describe the features of the lumbar vertebrae
- Large body
- spinous process short & sturdy
Describe the features of the Sacral vertebrae and coccyx
- Sacral promontory at S1
- Anterior & posterior sacral foramen
- Apex below S5
- Sacral hiatus on posterior
- Sacral canal
- Sacral & coccygeal cornua on posterior
- Superior articular facet posterior of S1
How are the vertebrae held together?
- Zygapophysial joints between superior & inferior articular processes
- Intervertebral discs
- Ligaments
What does the orientation of articular facets determine?
Types of movement possible
Describe the structure of intervertebral discs
-Annulus fibrosis= outermost, fibrocartilage ring attached to epiphyseal rim of vertebral body
-Nucleus pulposus= centre, gelatinous substance that acts as a shock absorber
Thickness determines flexability
Name the ligaments of the vertebral column and what they do
- Ligamentum flavum- binds lamina of adjacent vertebrae (behind pedicle)
- Posterior longitudinal ligament=C2-Sacrum, prevents posterior herniation of IV discs
- Anterior longitudinal ligament= Occipital bone & C1-sacrum
- Intertransverse ligament=between transverse processes
- Interspinous ligament= between spinous processes
- Supraspinous ligament=tips of spinous process C7-sacrum
Which ligament resists hyperflexion which resist hyperextension
Anterior longitudinal ligament only one to resist hyperextension all others resist hyperflexion
Describe what happens in whiplash
- Hyperextension of cervical neck
- Anterior longitudinal ligament torn
- Severe cases part of vertebral body avulsed & vertebrae dislocated- compression of spinal cord
What are the curvatures of the spine and where are they?
- Thoracic & sacral kyphosis (primary)
- Cervical & lumbar lordosis (secondary)
- Primary curvature present in foetus
What are the effects of ageing on vertebral bones?
- Osteoporosis= loss of trabeculae=compression fracture
- Loss of bone density=concave vertebral bodies
- Osteophyte development=increase force on rims of vertebrae
What are the effects of ageing on intervertebral discs?
- Slipped disc/ herniation of nucleus pulposus
- Posterolateral direction between L4/L5 or L5/S1
- Can compress spinal nerve roots= lower back pain or sciatica
- Severe cases compresses most of cauda equina (cauda equina syndrome)
Where does the caudal equina descend? What is this?
- Lumbar Cistern
- Subarachnoid space between termination of cord & termination of dura/arachnoid matter
Where does the lumbar cistern extend from?
Conus Medullaris L1/L2-S2
