Spinal cord and vertebral column Flashcards
Outline the support function of the vertebral common
Body weight, transmit forces, support the head, supports upper limb (and aid movement) and contain spinal cord
Outline the movement function of the vertebral common
upper limbs (extrinsic muscles from vertebral column to limb for example) and postural control and movement (intrinsic muscles between vertebral column or ribs)
Where is the greatest curvature of the vertebral column
between lower lumbar and beginning of sacrum
What determines whether a spinal curvature is primary or secondary
Think like foetus curled forward.
So if the curvature is ‘concaved anteriorly’ (i.e. bent forward as if to curl forward) it’s primary.
If the curvature is ‘concaved posteriorly’ (i.e. opposite to the foetal curve) it’s secondary
State which curves are primary and secondary
Primary- thoracic and sacral
Secondary- cervical and lumbar
Which curve might be exaggerated in pregnancy or obesity
secondary (lumbar) because there is increase weight hanging anteriorly so you need to lean forward more to shift the centre of gravity backwards so the lumbar curve is accentuated
What is exagggerated kyphosis
Accentuated thoracic curvature
What is exaggerated lordosis
Exaggerated lumbar curvature
What is scoliosis
Lateral curvature of the spine (including compression of organs and pain).. more noticeable when bent forward
Outline how many bones in each segment
Cervical- 7 thoracic -12 lumbar- 5 sacral- 5 fused coccygeal- 3-5 fused
Have to be able to label parts of each vertebra
…
What is the major weight bearing part of the vertebrae
Vertebral body
What is the vertebral arch
extends posteriorly, made up of ‘lamina’ which converge to form the spinous process.
Forms ‘roof’ of vertebral canal (image the spinal cord running along the the posterior aspect of the vertebral bodies and arch like the roof)
Attachment for muscles and ligaments and has sites for articulation of adjacent vertebrae
What do pedicles do
anchor the vertebra arch to the vertebral body
Shape of each vertbral body
Thoracic- heart
Lumbar- kidney shape (much bigger)
Cervical small
Names of 2 atypical vertebral
C1 (atlas)
C2 (
What is the transverse ligament of atlas’ function
it holds the vertebral body of C1 (which is actually on C2 but projects up) allowing turning of head from side to side
What sits on the superior articular surface of the atlas
the skull (occipital condyles)
What is the danger associated with the arrangement of the C1 vertebral body
The vertebral body projects up from C2 and is enclosed by the transverse ligament of the atlas (it’s called the odontoid peg) and in extreme flexion or extension of the neck, it can break free of the ligament and crush the spinal cord or lower part of the medulla causing death (mechanism of hanging or instant death in collisions)
Distinguishing feature of cervical vertebrae
Transverse foramina for the vertebral arteries
What is the equivalent of the spinous process on the atlas
Posterior tubercle
What is the name of the facet on the dens of the axis
Posterior articular facet for the transverse ligament of the atlas
What are the alar ligaments
Ligaments which go from the base of the skull to the odontoid peg
‘atlanto-occipital joint’ is the ‘YES’ joint so between skull and C1
‘Atlanto-axial joint’ is the NO joint so between C1 and C2 so the transverse ligament of the atlas is art of the median atlanto-axial joint)
(atlanto- refers to the atlas)
What is the cruciate ligament
The cross shape (superior and inferior longitudinal band vertical and the transverse ligament of the atlas) from skull down to C2
Main ligaments connecting the vertebral bodies
Anterior longitudinal ligament (limits extension- is stronger than posterior so extension less than flexion) posterior longitudinal ligaments (limits flexion) Ligamentum flavum LIMIT FLEXION and help support upright posture (between the lamina) Interspinous ligament (weak) (between the spinous processes) Supraspinous ALSO LIMITS FLEXION runs vertically down the back of the spinous processes (at end of the interspinous ligaments)
What can be the consequences of intervertbral disc degeneration
Reduction in size of the intervertbral foramina which can cause parasthesia (tingling/pins and needles) and pain
How do the spinal cords exit the spinal cord
C1-7 exit in intervertebral foramen above the verbrae
C8- coccygeal emerge below their respective vertebrae
Name of the bundle of nerves below L2 (i.e. peripheral nerves coming out of the spinal cord and travelling down to exit throigh intevertebral foramina at the correct level)
Cauda equina
Name the parts of the intervertebral disc
Around outside= anulus fibrosus, central= nucleus pulposus
Why is disc herniation more common in the lower vertbral
Because more weight is being transferred through them than further up.
Consequence of disc hernitation
Moves into the space containing the spinal cord or cauda equina so can cause pain and paraesthesia and possibly weakness and sciatica if in the lower back
Look at the movements of the spine
Bend forward (flex) bend back (extend), bend side to side (lateral flexion) and also rotation
List the 3 erector spinae muscles
most medial: spinalis group
More lateral: longissimus
Most lateral: iliocostalis
Keeps the spine upright
Differentiate the muscles innervated by the posterior and anterior rami of the spinal nerves
posterior- intrinsic muscles
anterior- extrinsic muscles e.g. of abdominal wall and limbs etc (MUCH larger)
Normal range of motion in cervical and thoracolumbar spine
cervical- 80 degrees rotation
45 degrees lateral flexion, 45 defrees flexion and extension
Thoracolumbar- 30 degrees extension and 90 degrees flecion, 30 dgrees, lateral flexion rotation (twist from waste) 30 degrees
Which extra space is present in the vertbral column but not the skull
Epidural space (because the periosteal layer of the dura mater reflects back on the exterior surface of the skull to leave just the meningeal layer in the spinal cord).
Where do the meninges end in the vertebral column
Arachnoid and meningeal layer of the dura continue further down the vertebral column than the spinal cord so S2 (so between L2 and S2 a huge subarachnoid space from which CSF can be taken).
The pia, which surrounds the spinal cord ends at the end of the spinal cord, but continues around the cauda equina as the filum terminale
What is the sacral hiatus
Lamina of the last few sacral vertbrae are not there so no fusion so there is a hole in the bottom of the spine through which an epidural injection can be given for example in sciatica to reduce inflammation.
The caudal epidural block involves placing a needle through the sacral hiatus to deliver medications into the epidural space
VS
Spinal anaesthesia which involves inserting needle inside the subarachnoid space into the CSF.
Spinal usually one shot (i.e. in surgery), epidural may have catheter for multiple injections e.g. in labour
Spinal blocks movement below the level of injection but epidural leaves almost normal function
Common spinal pathology
Low back pain
Prolapsed intervertebral disc –> sciatical
Spondolysis (degeneration)
Spondylolysis (stress fracture of pars interartcularis)
Spondylolisthesis (forward displacement of vertebra)
Spondylitis (inflammation of vertebrae)
Common spinal injuries
Injuries to axis and atlas
