The Vertebral Column

Question 1

What are the 5 gross functions of the vertebral column?

Answer 1

1) centre of gravity of the body➡️ the weight of the body is projected into lower limbs about a line that passes centrally through the natural curvatures of the vertebral column
2) attachments for bones above, centrally and below
3) attachments for trunk muscles➡️ upright posture is determined by continuous low level contraction to support body weight
4) protection and passage of the spinal cord
5) segmental innervation of the body

Question 2

What is the general structure of a vertebrae?

Answer 2

A vertebral body (anteriorly) and a vertebral arch posteriorly
Between them they enclose the spinal cord or vertebral foramen/neural foramen

Question 3

Describe the vertebral body.

Hint: size, contact, cartilage.

Answer 3

usually the largest part of the vertebrae and main weight bearing
main site of contact between adjacent vertebrae
lined with hyaline cartilage
linked to adjacent vertebral bodies by inter vertebral discs
size of body of vertebrae increases from top downwards
vertebral bodies and intervertebral discs interdigitate from C2/3 to L5/S1

Question 4

Describe the vertebral/ neural arch.

Hint: processes, elaborations.

Answer 4

Spinous process: midline + posterior
Transverse process: laterally on each side of midline
Pedicle: between body and transverse process
Lamina: between articular process and spinous process
Articular process: one above one below (superior inferior), cartilage lined allow for synovial joints to be formed between neural arches of adjacent vertebrae, strengthened by ligamentum flavum

Question 5

What are the functions of the vertebral column?

Answer 5

Anchors the axial skeleton

Accounts for 42% of height-70-75cm long

Question 6

Describe the joint formed between adjacent neural arches.

Answer 6

synovial variety
prevent anterior displacements of the vertebrae
allow for limited movements and can bear weight when uprighting
each pedicle has 2 notches inferior and superior
notches form intervertebral foramen
segmental nerves pass from cord to periphery through the foramen
dorsal root ganglia found here

Question 7

What is the intervertebral disc?

Answer 7

a disc of tissue separating successive vertebrae between C2/3 to L5/S1 intervertebral levels
forms. Joint between vertebral bodies➡️ joints are secondary cartilaginous joints known as symphysis
flexibility of vertebral column, shock absorber
not uniform size ➡️ increase from superior to inferior, wedge shaped in lumbar and thoracic, thickes anteriorly, thinnest posteriorly
wedge shaped accounts for secondary curvature of the spine
19cm of spine (25% of vertebral column)
high water content keeps it turgid
may shrink with age
2 regions: Central region (nucleus pulposus) and peripheral region (annulus fibrosus)

Question 8

Describe the vertebral column in the foetus.

What is the curvature called when exaggerated?

Answer 8

It lies in a single curvature➡️ figure of C shape ➡️ faces anteriorly (concave)
‘primary curvature’ retained throughout life in the thoracic sacral and coccygeal parts
when exaggerated the anterior curvature is known as kyphosis

Question 9

Describe the vertebral column in the young adult.

Answer 9

4 distinct curvatures➡️figure of S (sinusoidal profile)
sinuous bends give the column great resilience
2 anterior flexions (anterior concavities) and 2 posterior flexions
↪️anterior concavities are continuous of the primary curvature of the foetus
↪️posterior concavities are secondary curvatures

Question 10

Describe the vertebral column from the foetus to young adult.

Answer 10

the primary concave curvature is remodelled in parts
the C-shaped column opens up to elongate
the cervical spine develops the first posterior concavity when a young child begins to lift its head
the lumbar spine also opens up during crawling until the child begins to stand up and walk
a second posterior concavity then appears and becomes the secondary curvature

Question 11

Describe the normal curvatures of the vertebral column.

Answer 11

4 curvatures: 2 primary, 2 secondary
Sequentially from top-bottom: Cervical (secondary), Thoracic (primary), Lumbar (secondary), Sacral (primary).
Kyphosis: an abnormally increased posterior convexity of the thoracic spine
2 primary= kyphosis
2 secondary= Lordoses

Question 12

Describe the vertebral column in old age.

Answer 12

the secondary curvatures start to disappear➡️returns to original shape in foetus
a fully continuous primary curvature re establishes
the vertebral column closes up again

Question 13

Describe the overall assembly of the vertebral column.

Answer 13

It is built from stacking 33 vertebrae on top of each other
2 assemblies are known:
↪️discrete single vertebrae-24 separate vertebrae all capable of movement
↪️fused vertebrae-9 vertebrae fuse to give 2 innovate structures
- sacrum (fusion of 5 vertebrae)
- coccyx (fusion of 4 vertebrae)

Question 14

Describe the Annulus Fibrosus.

Answer 14

Highly complex design made from a series of annular bands with varying orientations.
outer bands are collagenous, inner bands are fibro-cartilaginous
very resilient, stronger than the vertebral body
surround nucleus pulposus, it is the real shock absorber

Question 15

Describe the Nucleus Pulposus.

Answer 15

is jelly-like, has high osmotic pressure, acts ass a water reservoir for the disc
changes in size throughout the day depending on water distribution within the disc
changes in size with age
surrounded entirely by annulus fibrosus, centrally located in the infant,found posteriorly in adult
can herniated through annulus fibrosus if there is degeneration (slipped disc)

Question 16

Describe the degeneration of the nucleus pulposus.

Answer 16

the nucleus can dehydrate with age, height of the IV disc then decreases
when this happens, load stresses on the IV disc alter, leading to reactive marginal osteophytosis adjacent to the affected end plates
as the disc space decreases in height, increased stress is also placed on the facet joints which can lead to osteoarthritis of the facets at the same level
as age increases, progressive degeneration of the nucleus lead s to decreasing disk height which could lead to congestion in the IV foramen and compression of segmental nerves

Question 17

What is degenerative annular disease?

Answer 17

degeneration of the annulus fibrosus leads to marginal osteophytosis at the endplates, progressive degeneration of the annulus leads to increasing osteophytosis of the disc space margins- the height of the disc space is largely preserved
usually seen in thoracolumbar spine of persons over 50= ‘spondylosis deformans’ or ‘senile ankylosis’

Question 18

What is degenerative disc disease?

Answer 18

Degeneration of the annulus and the nucleus pulposus occur concurrently.

Question 19

Describe Herniated IV disc.

Hint: occurrence, paralysis.

Answer 19

Occur most commonly, Posterolaterally which results in compression of spinal segmental nerves
️posterior herniation may compress the spinal cord➡️ complete paralysis

Question 20

What are the ligaments of the vertebral column? And where do they occur

Answer 20

ligaments run along the longitudinal axis of the vertebral column
1 occurs anteriorly to vertebral column=anterior longitudinal ligament
1 occurs posteriorly= posterior logitudinal ligament
anterior longitudinal ligament is much stronger

Question 21

Describe the anterior longitudinal ligament.

Hint: location, strength, binding.

Answer 21

it is a flat band that broadens as it passes downwards
extends from the anterior tubercle of the atlas to thr front upper part of the sacrum
it is firmly united to the periosteum of the vertebral bodies
it is free over the vertebral discs
it is the stronger of the 2

Question 22

Describe the posterior longitudinal ligament.

Hint:location, attachments.

Answer 22

extends from the back of the body axis (2nd cervical vertebrae) to the canal of sacrum
it is continued above the body of the axis as the ‘membrane tectoria’
it narrows gradually as it passes downwards
it has serrated margins➡️serrations=broadest over the IV discs to which they are firmly United
the ligament narrows over vertebral bodies
they are separated from vertebral bodies by the emerging basivertebral veins

Question 23

What is the ligamentum flava?

Hint: movements, colour, structure.

Answer 23

stretched by flexion of the spine
yellow in colour from high content of elastic fibres
they join lamina of adjacent vertebrae
they are attached to the front of the upper lamina and to the back of the lower lamina

Question 24

What is the Supraspinous ligament?

Hint: function, structure, movements.

Answer 24

lax in extended spine
joins the tips of adjacent spinous processes
strong bands of white fibrous tissue
full flexion effectively prevents effector spinae muscles from extending the spine
in flexion of the vertebral column, they are drawn taut to mechanically support the vertebral column

Question 25

What is the interspinous ligament?

Hint: structure.

Answer 25

relatively weak sheets of fibrous tissue
they unite spinous processes along their adjacent borders
well developed in Lumbar region and fuse with Supraspinous ligaments

Question 26

What is the ligament nuchae?

Hint:attachments, function.

Answer 26

proximal: occiput (back of skull)-occipital protuberance
distal: thoracic spinal ligaments-interspinous ligament and Supraspinous ligament
intermediate: all cervical vertebrae-spinous processes
it maintains the secondary curvature of the spine
helps the cervical spine support the head
acts as a major site of attachment of neck and trunk muscles e.g. trapezius, rhomboids)

Question 27

What are the discrete vertebrae of the column and what are the fused?

Answer 27

Discrete: cervical (7), Thoracic (12), Lumbar (5)
Fused: sacrum (5), coccyx (4)

Question 28

What are is the size of the cervical vertebrae and what are the 2 distinguishing features?

Answer 28

smallest of the discrete vertebrae, form skeleton of the neck
1⃣ Bifid spinous process
2⃣ oval transverse foramen in the the transverse process
- foramen transversarium
- vertebral foramen passes through the foramen except C7
- C7 foramen passes through the smaller accessory vertebral veins
Has a large vertebral foramen

Question 29

What is the size and three distinguishing features of thoracic vertebrae?

Answer 29

intermediate in size, increase in size from above-downwards
1⃣facets on the sides of the body-Demi facets for articulating with head of rib
2⃣facets on the transverse processes (except T11 and T12)-coastal facets for articulations with tubercle of rib
3⃣vertebral foramen is small and circular

Question 30

What are the four distinguishing features of the Lumbar vertebrae?

Answer 30

1⃣ Largest of the discrete vertebrae
2⃣ Lack of foramina on transverse processes
3⃣ Lack costal facets on the side of the body
4⃣ Vertebral foramina are triangular and small

Question 31

What is the difference and similarities between the atlas and the axis?

Answer 31

the first cervical vertebra or C1 is the atlas
the second cervical vertebra or C2 is called the axis
they are both atypical vertebra-structurally and functionally

Question 32

Describe the Atlas.

Hint: articulations, structure, size, attachments.

Answer 32

skull above- atlanto-occipitial joint, axis below-atlanto-axial joint
lacks a body and spinous process, each neural arch is thick and strong to form a powerful lateral mass
widest cervical vertebrae
it’s body is fused with that of the axis to form the dens or Odontoid process

Question 33

Describe the axis.

Hint: strength, 3 main features, function, fracture.

Answer 33

strongest cervical vertebra
1⃣the Odontoid process or ‘dens’
2⃣rugged lateral mass
3⃣large spinous process
dens prevents horizontal displacement of atlas
fractures and dislocates in hanging to give hangmans fracture

Question 34

What are some injuries of the vertebral column and which areas of the spine are susceptible?

Answer 34

cervical spine susceptible to:-whiplash injuries in RTA
- sports injuries-rugby scrum, high tackles
lumbar spine susceptible to herniation of L4/L5 or L5/S1 IV discs
side to side curvatures of the spine can result from unbalances muscle tone of trunk muscles between right and left side to give rise to sclerosis