Vertebral Column

Question 1

How many of each vertebrae are there

Answer 1

7C, 12T, 5L, 5S (fused into one sacrum) and 4Co (fused into one coccyx).

Question 2

What is the function of the vertebrae? How does it achieve this function?

Answer 2

Function is to project weight onto lower limb, attachment of bones and muscles, shock absorption, protection and maintains centre of gravity. Column gets larger as you move down to help support the compression forces that get larger.

Question 3

What movement are the spine capable of?

Answer 3

Movements of the the spine are rotation, flexion, extension and lateral flexion.

Question 4

Why is the sacrococcygeal wider than the rest of the vertebrae?

Answer 4

Sacrococcygeal is widened to help spread the weight of the pelvis.

Question 5

What important function relating to the thoracic cage does the vertebrae do?

Answer 5

The vertebrae holds the thoracic cage upwards preventing it from collapsing into the abdomen.

Question 6

Describe the structures of a vertebrae

Answer 6

Vertebrae are split into the vertebral body and vertebral arch; the vertebral foramen is the hole in-between them whilst the intervertebral foramen are the holes between two adjoining vertebrae (alone they are called superior and inferior intervertebral notches. The vertebral arch contains the spinous process, two articular processes and 4 articular processes (zygapophyses) which lock into place with vertebrae above and below preventing them from sliding over each other, the orientation of these zygapophyses determines how much flexion and extension can take place. They interlock via synovial joints sometimes called facet joints.

Question 7

Which type of cartilage lines the articular joints of the vertebrae.

Answer 7

The articular surfaces of the vertebral body are lined by hyaline cartilage and they bare most of the weight.

Question 8

Where is the most common place for a slipped disc to occur?

Answer 8

Slipped disc – occurs most commonly at L4/L5 and L4/S1 junction.

Question 9

What is the process leading up to a herniation?

Answer 9

Disc degeneration (weakening of annulus fibrosis due to age), Prolapse – protrusion of the nucleus pulposus, Extrusion – nucleus pulposus breaks through the annulus fibrosis, sequestration nucleus pulposus escapes the disc space and impinges on the spinal cord.

Question 10

Which direction does a disc usually herniate in and how doesits direction effect the severity of the situation?

Answer 10

Usually herniates posterolaterally compressing nerve roots, rarely herniates posteriorly – medical emergency.

Question 11

What casues the degeneration of the discs and the pain as it degenerates?

Answer 11

Degeneration due to age and dehydration causes a decrease in height between the vertebrae, this extra stress and pressure causes marginal osteophyotsis, also the increased pressure causes pain at facet joints and compression of intervertebral foramen causes pain at spinal roots.

Question 12

What is Cervical Spondylosis

Answer 12

Cervical spondylosis results from degenerative osteoarthritis resulting in osteophyte formation putting pressure on nerve roots resulting in radiculopathy (pain and parasthesia limited to one dermamyotome), or myelopathy (effecting the body globally due to damage to spinal cord).

Question 13

Describe a cervical vertebrae

Answer 13

Cervical vertebrae – smallest, bifit spinous process, transverse foramen and triangular vertebral foramen.

Question 14

Describe a thoracic vertebrae

Answer 14

Thoracic vertebrae – demi and costal facets for attachment of the ribs, vertebral foramen is small and circular.

Question 15

Describe a lumbar vertebrae

Answer 15

. Lumbar vertebrae – largest of the individual vertebrae, large body and small triangular vertebral foramen.

Question 16

Describe the Sacrum and coccyx

Answer 16

Sacrum and coccyx fused into one with sacral foramina, sacral canal and sacral hiatus.

Question 17

Describe C1 (atlas)

Answer 17

C1 – atlas, allows for nodding movement by articulating with occiput bone and contains no vertebral body or spinous process.

Question 18

Describe C2 (axis)

Answer 18

C2 – axis, has a large spinous process and allows for shaking of head as it contains the vertebral body of atlas (dens) and a transverse ligament.

Question 19

Describe C7 (vertebrae prominens)

Answer 19

C7 – vertebrae prominens has a very large spinous process (the first visible one on people’s back).

Question 20

What is a hangman’s fracture?

Answer 20

Hangman’s fracture – hyperextension resulting in fracture of the C2 pedicles and a forward displacement of C1 and C2’s body onto C3.

Question 21

When is a peg fracture?

Answer 21

Peg fracture occurs due a large force at the back of the head resulting in the dens being fractured.

Question 22

What is a Jefferson’s fracture?

Answer 22

Jefferson’s fracture – high axial load resulting in a 4-way fracture of the atlas into 4 parts at the posterior and anterior arches.

Question 23

What is whiplash injury and how is our body evolved to protect ourselves from this?

Answer 23

Whiplash injury occurs when the cervical vertebrae slide over each other and impinge on the spinal cord then spring back into place – cervical vertebrae very mobile. The large foramen adds some sort of protection from this.

Question 24

Describe the general structure of our intervertebral discs.

Answer 24

Intervertebral discs have a very high water content that keeps it turgid, they have a slight wedge shape to account for the secondary curvature of the spine.

Question 25

How do these discs change as we age?

Answer 25

As we age they lose water and decrease in size.

Question 26

What 2 main structure make up the intervertebral discs?

Answer 26

The Nucleus pulposus and the annulus fibrosis

Question 27

Describe the Nucelus Puplosus

Answer 27

The nucleus pulposus in the middle which is a remnant of the notochord, it is jelly like and very osmotically active, in an infant it is centrally located and in an adult it is more posterior.

Question 28

Describe the Annulus Fibrosis

Answer 28

Surrounding the nucelus pulposus is the Annulus fibrosis formed from rings of lamellae of annular bands in different orientations, outer is cartilaginous whilst inner is fibrocartilaginous, it is avascular and a-neural.

Question 29

What is the major functions of the intervertebral discs

Answer 29

Major shock absorber and highly resistance to compression (more than the vertebrae).

Question 30

How many curvatures of the spine do we have as a newly born infant?

Answer 30

As a baby we have one clear C shape, this is only maintained in the thoracic sacral and coccygeal regions.

Question 31

What is a kyphosis and what is a lordosis

Answer 31

A kyphosis is a curve causing the spine to curve around your anterior side whilst a lordosis curves backwards.

Question 32

How does the single curvature we have as a baby change as we age?

Answer 32

2 secondary lordosis (secondary curvatures) appear as we progress from a foetus to a baby to a toddler and finally a walking adult. End result is a sinusoidal profile great for large flexibility and resisting compression.

Question 33

What happens to the curvatures of our spine as we age?

Answer 33

As we age our secondary curvatures disappear and we return to a bent over old person known as senile kyphosis.

Question 34

Give an example of when curvatures become exaggerated physiologically

Answer 34

Physiological exaggerations of curvature can occur such as in pregnancy.

Question 35

Describe three different pathological curvatures of the spine and their symptoms.

Answer 35

Pathological curvatures include – kyphosis which is an exaggeration of the C shaped primary curvature in either the thoracic or lumbar regions resulting in wedge shaped intervertebral discs, can have cosmetic consequences or impinges lung capacity.

Scoliosis – lateral curvatures of the spine occurring due to congenital and idiopathic reasons or neuromuscular disease, again results in cosmetic consequences or impinges lung capacity.

A kyphoscoliosis is a combination and is much more debilitating.

Question 36

What are the functions of the 5 major ligaments relating to the spine?

Answer 36

Anterior and posterior longitudinal ligaments on each side of the vertebral bodies preventing hyperflexion and hyperextension, ligamentum flavum connecting laminae which stretches during flexion and the elasticity helps to extend back, interspinous ligament unites spinous processes supplying stability in flexion and fuses with the supraspinous ligament which connects the tips of adjacent spinous processes.