Vertebral Column & Spinal Cord

Question 1

At what vertebral level does the spinal cord terminate in adults and children?

Answer 1

L1/L2 in adults

L3 in children

Question 2

What vertebral level is lumbar puncture performed?

Answer 2

L3-L4 or L4-L5

Question 3

What’s the surface anatomy of the cauda equina and the meninges?

Answer 3

Cauda equina: termination of spinal cord (L1/L2) through spinal canal -> S2

Meninges: subarachnoid space extends from foramen magnum of skull -> S2

Question 4

Describe the layers a needle goes through to obtain CSF sample and how this differs to epidural anaesthetic

Answer 4

Skin -> subcutaneous fat -> supraspinous ligament -> interspinous ligament -> ligamentum flavum -> epidural space -> dura mater -> subdural space -> pia mater -> subarachnoid space filled with CSF

Anaesthetic: level of needle insertion depends upon site required for anaesthesia; stop inserting the needle once you’ve lost feeling of resistance as this will have pierced ligamentum flavum

Question 5

Explain the structure of an IV disc

Answer 5

Nucleus Propulsus (rubbery core) made of GAGs to attract H20
Annulosus Fibrosus fibrocartilage rings surround NP

Attach to bodies of adjacent vertebrae from below C2 downwards via Hyaline cartilage (secondary cartilaginous joint)

Question 6

In which direction do IV discs commonly herniate?

Answer 6

Postero-laterally (has least support from posterior longitudinal ligament)

Compress spinal nerve emerging below the body passing inferiorly

Question 7

What are the roles of the vertebral column?

Answer 7

Carry and protect spinal cord and nerves
Provide support to thoracic rib cage
Transfer weight from upper body to lower limbs for stability
Shock absorbing
Muscle attachment point

Question 8

What are the different vertebral regions?

Answer 8

C1-C7
T1-T12
L1-L5
S1-S5
Coccyx

Question 9

Explain the structure of a typical vertebra - what makes up the neural arch?

Answer 9

Neural arch = pedicle + transverse process + lamina + spinous process

Vertebral body and vertebral canal
Articular facets

Question 10

How do the C1 and C2 vertebrae differ from others?

Answer 10

(C1-atlas) Carries weight of cranium so has no body
Joins to occipital condyle on skull to permit movement

C2 (axis) has odontoid process to attach to C1 - can be fractured and impinge spinal cord

Question 11

What does the vertebral artery run through on the cervical vertebrae?

Answer 11

Foramen transversarium - may be compressed in foramen narrowing

Question 12

How do thoracic vertebrae differ from cervical?

Answer 12

Increase in size

Contain articular facets for the ribs

Question 13

How are lumbar vertebrae specialised?

Answer 13

Have a larger body for stability and weight transmission

Articulations are aligned to prevent rotation

Question 14

How are the sacral vertebrae specialised?

Answer 14

5 vertebrae fused together to transmit weight to pelvic girdle (down through lower limbs)

Question 15

What are the joints between articular facets of adjacent vertebrae?

Answer 15

Zygapophyseal joints (synovial plane)

Question 16

What’re the mechanics of IV discs to limit movement between vertebral bodies?

Answer 16

Force applied to vertebral column increases pressure in NP

= increases tension in surrounding AF

Question 17

What are the ligaments of the vertebral column?

Answer 17

Ligamentum niche can be palpated in midline posterior neck
Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Anterior and Posterior longitudinal ligaments

Question 18

What are the natural spinal curvatures?

Answer 18

Cervical and Lumbar lordosis (curves anteriorly)
Thoracic and Sacral kyphosis
To balance centre of gravity

Question 19

What’s spondylolysis?

Answer 19

Fracture in articular facets without vertebral displacement (spotty dog collar sign)

Question 20

What’s spondylolisthesis?

Answer 20

Lumbar vertebrae moves anteriorly (slips forwards)

Question 21

What movements is the vertebral column capable of?

Answer 21

Flexion, extension, rotation, lateral flexion

Question 22

What muscle group keeps you upright?

Answer 22

Erector spinae group

Question 23

What can get trapped in the suboccipital triangle? Symptoms?

Answer 23

C2/C3 dorsal rami

Posterior headache/occipital neuralgia

Question 24

Where do spinal nerves exit the vertebral levels?

Answer 24

C1-C7 exit above vertebra
C8 downwards exit below

Via intervertebral foramen

Question 25

How is grey and white matter arranged in the spinal cord?

Answer 25

Grey matter (cell bodies) in the centre
White matter (myelinated tracts) in the outside
Dorsal = sensory
Ventral = motor
Lateral horn = autonomic T1-L2 and S2-S4 only

Question 26

What types of neurone do spinal nerves contain (mixed)?

Answer 26

Somatic motor
Somatic sensory
Visceral sensory
Autonomic (sympathetic T1-L2, parasympathetic S2-S4)

Question 27

What’s the cauda equina? Cauda equina syndrome?

Answer 27

Collection of lumbar and sacral spinal nerves (after termination of the spinal cord at L1)
Supplies lower limb, pelvic floor, urinary and anal sphincters

Syndrome = compression of these nerves (tumour, spondylolisthesis, disc herniation, canal stenosis)
Reduced ankle jerk S1-S2 reflex

Question 28

What’re the surface markings for caudal anaesthesia?

Answer 28

Line joining left and right PSIS /S2 spinous process

Sacral hiatus located at inferior apex of equilateral triangle