Vertebral column - Osteology/ Vasculature/ innervation

Question 1

Discuss the primary and secondary curvatures of the spine

Answer 1

• primary: kyphoses - thoracic & spinal
  = develop during fetal period and retained throughout life due to differences in height between anterior and posterior part of vertebrae
• secondary: lordoses - cervical & lumbar
  = develop during fetal period but not obvious until infant can hold their own head/ start to walk

Question 2

What are the 3 main features of typical vertebrae?

Answer 2

• vertebral body: restrict movement
• vertebral arch: pedicles & laminae - protect spinal cord
• 7 processes: 1 spinal, 4 articular, 2 transverse

Question 3

What forms zygopophyseal joints?

Answer 3

= aka facet joints - superior and inferior articular facets

Question 4

Describe thoracic vertebrae in terms of:

• body
• vertebral foramen
• transverse process
• articular process
• spinous process

Answer 4

• heart shaped- demifacets for heads of ribs
• circular/ smaller than lumbar
• length diminishes from T1-12/ costal facets on t1-10 for articulation with tubercles of ribs
• facets frontally orientated in AP view - superior: anterolateral/ inferior: posteromedial
• longer, sloping - distal orientation/ overlap vertebral bodies

Question 5

Describe lumbar vertebrae in terms of:

• body
• vertebral foramen
• transverse process
• articular process
• spinous process

Answer 5

• large, kidney shaped
• triangular foramen
• long/ slender (except L5 = short & pyramidal)
• superior facets: anteromedial/ inferior facets: posterolateral
• spinous process: short & sturdy - hatchet shaped

Question 6

What is the sacral promontory?

Answer 6

• anterior edge of S1

Question 7

What exits the 4 pairs of sacral foramina?

Answer 7

rami of S1-4 nerves & accompanying vessels

Question 8

How are the crests formed on the posterior surface of sacrum?

Answer 8

median crest - fusion of spinous processes
intermediate crest - fusion of articular processes
lateral crest - fusion of tips of transverse proceeses

Question 9

What has resulted in sacral hiatus?

Answer 9

absence of laminae or spinous processes of S4-5

- leads to spinal canal

Question 10

What are the sacral cornua?

Answer 10

horns - inferior articular processes of S5 - landmark for sacral canal

Question 11

What is the shape of the lateral view of the coccyx?

Why is it significant?

Answer 11

auricular shape - articulates with ilium to form sacroiliac joint

Question 12

What is the coccyx a remnant of?

Answer 12

skeleton of embryonic caudal eminence

Question 13

Describe the arterial supply of the vertebral column (overview)

Answer 13

periosteal and equatorial branches of major cervical and segmental arteries and spinal branches

Question 14

Describe the spinal branches in each region

Answer 14

• ascending cervical and vertebral arteries in neck
• posterior intercostal arteries in thoracic region
• subcostal/ lumbar arteries in abdomen
• iliolumbar/ lateral & medial sacral arteries in pelvis

Question 15

Discuss how spinal branches divide once they enter the IV foramen

Answer 15

• anterior/ posterior vertebral canal branches
  –> ascending/ descending branches
  (anterior -> nutrient arteries to vertebral bodies)
  (i) radicular arteries - anterior/ posterior roots of spinal nerves & coverings
  (ii) segmental medullary arteries - continue to spinal cord

Question 16

Describe how spinal veins supply vertebrae

Answer 16

spinal veins form venous plexus –> internal vertebral epidural venous plexus & external vertebral venous plexus

• basivertebral veins (within the vertebral bodies) empty into these
• veins from spinal cord and venous plexus drain into intervertebral veins - accompany spinal nerves through IV foramen to drain into vertebral veins of neck and segmental veins of trunk

Question 17

Describe the innervation of the vertebral column

Answer 17

mostly meningeal branches of spinal nerves (except zygapophyseal joints supplied by articular branches of medial branches of posterior rami)

• branches outside canal supply annulus fibrosi and ALL
• recurrent branches -other ligaments, spinal dura mater and periosteum

Question 18

Which ligament limits hyperextension of spine?

Answer 18

anterior longitudinal ligament

Question 19

Which ligaments chiefly limits hyperflexion?

Answer 19

ligamentum flavum

Question 20

What ligaments are unique to the cervical vertebrae?

Answer 20

• nuchal ligament - proximal attachment for trapezius and rhomboids
• transverse ligament of atlas - anchor dens