Vertebral Coloumn 1 and 2

Question 1

Describe some general characteristics of the spine

Answer 1

• Segmented column consisting of bone
  elements, intervertebral discs and ligaments
• 5 different regions: cervical, thoracic, lumbar,
  sacral, coccygeal (on average 24 presacral
  vertebrae)
• Antero-posterior view: column appears to be
  straight
• Lateral view: four dorso-ventral curves:

1) Cervical lordosis, 2) thoracic kyphosis, 3)
lumbar lordosis and 4) sacro-coccygeal kyphosis

Question 2

Describe the joint facet orientation and spine movement for cervical, thoracic and lumbar spines

Answer 2

Joint facets facing superior and
inferior: flexion/extension,
lateral bending, rotation
Most mobile region of the spine

Joint facets facing anterior and
posterior: rotation
Least mobile region of the spine

Joint facets facing medial
and lateral: mostly
flexion/extension

Question 3

Describe the postnatal development of spinal curves

Answer 3

Cervical lordosis: carrying the head
upright (starts around 6 months)
Thoracic kyphosis: already present
at birth but gets more accentuated
throughout postnatal development
Lumbar lordosis: upright
walking (starts around 12 months)
Sacrum and coccyx kyphosis: upright
walking (approx. same start as lumbar
lordosis)

Question 4

Describe spinal curve development and growth

Answer 4

During postnatal ontogeny, the curves
mainly develop due to the adjustments
of the intervertebral disc height and
shape
* In later life – after skeletal maturation -
the vertebral body bone tissue
reorganises itself into wedge-shapes
that accentuate the curves

Question 5

Describe vertebral growth patterns and explain what arm elements are

Answer 5

The neonate vertebrae have 2 separate
arch and 1 body element, connected
with cartilage which allows for the
growth of all parts of the vertebrae
* The arch elements are the first to fuse
between 1 - 6/7 years of age
* The united arch merges with the bodies
between 2 and 6 years on the presacral
spine and up to 12-25 years in the
sacrum and coccyx.

Question 6

Scoliosis

Answer 6

A lateral curvature, combined
with a rotation is called a
scoliosis
The reasons why a scoliosis
develops are manifold and
range from congenital (e.g.
gene defects, developmental
issues) to neuromuscular (e.g.
muscular dystrophies) and
idiopathic (unclear cause

Example of congenital
scoliosis: Presence of a
hemi-vertebra induces
a scoliosis during
postnatal ontogeny

Question 7

What are the issues with damaging the cervical rib- thoracic outlet syndrome?

Answer 7

Compression of the brachial plexus:
Can result in paraesthesia along the ulnar border of the
forearm, wasting of hypothenar and interossei muscles,
ulnar lumbricals and adductors of the thumb
Compression of the subclavian artery: Can simulate
and/or produce an aneurysmal dilation of the artery
and related complications (e.g. thrombi)

Question 8

Describe lumbar ribs

Answer 8

A supernumerary rib which arises
from a lumbar vertebra (L1) –
often, a transverse foramen is
present as well
* Located below the normal last
floating rib (rib pair 12)
* Genetically (congenitally) induced
– hox gene activity
* Frequency is likely higher than
that of cervical ribs but appears
rare due to not being reported
much in clinical imaging
* Lumbar ribs are not generally
associated with medical
conditions (hard to spot)

Question 9

Describe spondylolysis

Answer 9

A deformation/defect or a stress fracture of the vertebral arch (pars inter-articularia)
and/or articular processes

• Caused by overload of the lumbar spine – but a genetic component is often
  involved as well, where this part of the vertebra is less than average tall

Spondylolysis can result in one or more vertebrae becoming unstable and slipping out
of place = Spondylolysthesis

Question 10

Describe intervertebral discs

Answer 10

Between all neighbouring vertebrae,
there is a fibrocartilaginous joint, made
by the intervertebral disc (exception:
C1-C2)
* The discs have a fibrocartilaginous outer
ring – the annulus fibrosus and a gellike fluid core – the nucleus pulposus
* There are two cartilaginous endplates
made of hyaline cartilage which anchor
the disc to the bone of the vertebral
body

Question 11

Describe the structure of intervetebral discs

Answer 11

Annulus fibrosus: layers of
fibrocartilage and collagen
fibres organized in
alternating directions and
layers

• Nucleus pulposus: gel-like
  fluid contained within the
  annulus fibrosus
• No nucleus pulposus
  between C1 and C2 and in
  the sacrum and coccyx

Question 12

Describe the ageing disc and associated injuries

Answer 12

After 40 years of age, more than half the population will have
some degree of disc degeneration due to:
* A dehydrating nucleus pulposus which leads to lesser
ability of the disc to shock-absorb
* The annulus fibrosus becomes weaker and the endplates tend to be more brittle

All this can lead to a loss of height, but these changes are
natural wear-and-tear and the process is pain free.

The more brittle annulus fibrosus and cartilaginous endplates
can lead to:
* Tears in the annulus fibrosus and the endplates
* Bulges and protrusions – temporary or permanently of
the annulus fibrosus into the vertebral canal or the
intervertebral foramina
* Herniating or extruding nucleus pulposus through a rent
in the outer layers of the annulus fibrosus or the endplate

Question 13

Describe the ligaments of the vertebral body and lamina

Answer 13

Anterior and posterior
longitudinal ligaments:
continuous bands from skull
to sacrum, on anterior and
posterior surfaces of the
vertebral bodies

Ligamenta flava: connect
the vertebral arches; they
are highly elastic hence their
yellow appearance (flavum =
yellow, lat.)

Question 14

What are the ligaments of the atlanto-occipital area

Answer 14

Alar ligaments
Transverse atlantic ligament
Longitudinal fascicles
Together = cruciform ligament

Question 15

What are the types of intrinsic back muscles

Answer 15

Longitudinal muscles – together
known as the Erector spinae – are
mostly involved in antagonising
flexion and faciliate extension of
the vertebral column and skull
* Iliocostalis
* Longisssimus
* Spinalis

Transverse (or rotator) muscles –
they are important for rotating
and bending the spine as a whole
and neighbouring vertebrae
against each other
* Most prominent in the lumbar
region: Multifidus

Question 16

What is thoracolumbar fascia

Answer 16

The thoracolumbar fascia covers the intrinsic back muscles and is continuous with the superficial lamina of the
deep cervical fascia at the back of the neck

• In the lumbar region the fascia consists of three layers;
  ↙ = posterior/superficial, ↗ = middle and
  ↓ =anterior/deep, enclosing the erector spinae muscles in one compartment and the quadratus lumborum in
  another

Question 17

What are the boundaries of the spinal canal

Answer 17

Continuous tube formed by
the stacked vertebrae C1-S5
(and intervertebral discs)

• Anterior boundary: vertebral
  body and posterior
  longitudinal ligament
• Posterior boundary: Vertebral
  arches and ligamenta flava
• Lateral openings
  (intervertebral foramen)
  between pairs of vertebrae

Question 18

What are the contents of the spinal canal

Answer 18

Epidural fat pad (contains
internal venous plexus)
* Meninges of the spinal
cord (continuous with the
meninges of the cerebrum)
and cerebrospinal fluid
* The spinal cord itself

Question 19

What are the 3 membranes that envelope the CNS and spinal cord

Answer 19

Tubular extension of the central nervous system;
transmission of neural inputs between the periphery and the brain
System of 3 membranes which envelope the central
nervous system and the spinal cord:
* Dura mater
* Arachnoid mater (Subarachnoid space)
* Pia mater

Question 20

What is cerebrospinal fluid

Answer 20

Produced in the choroid plexi
of the lateral ventricles of the
cerebrum (see NSB module later
this term)
* Circulates via 3rd and 4th
cerebral ventricles and the
median and lateral apertures
of the 4th ventricle around the
cerebrum and cerebellum and
the spinal cord
* Drains via cerebral sinuses
and likely roots of spinal
nerves

Question 21

Describe dura matter

Answer 21

Outer-most layer, a thick, fibrous sheet
* Fused partially to the periosteum of the
skull bones (see NSB module later this
term), at spinal level tethered to foramen
magnum and 2nd sacral vertebra only
* Separated from spinal canal walls by the
epidural fat and vessel layer
* Dura is drawn out with the spinal nerves
via the intervertebral foramina
* Small, capillary space between dura and
arachnoid mater = subdural space
(marked green on slide)
* Highly sensitive to pain, innervation by
trigeminal and vagus nerves (NSB)

Question 22

Describe arachnoid matter

Answer 22

Middle layer
* Sends web-like fascicular
processes towards the
pia mater and attaches
to it
* “Space” between
arachnoid and pia mater
= subarachnoid space is
filled with cerebrospinal
fluid

Question 23

Describe pia mater

Answer 23

Inner most layer, delicate,
thin membrane, difficult
to dissect off the spinal
cord
* Highly vascularised
* Attaches to the Dura
mater (piercing through the
arachnoid mater) via
denticulate ligaments

Question 24

What are the extensions of the spinal chord

Answer 24

Caudal extension of the central nervous
system (intra-cranial = medulla
oblongata)
* Lower cervical/upper thoracic
enlargement
* Lumbar enlargement
* The spinal nerves emerging from the
lumbar and sacral segments form the
Cauda equina (= horsetail)

Question 25

Describe spinal chord growth from neonate to adulthood

Answer 25

The spinal cord and the vertebral column follow different growth patterns from around the 9th fetal month because musculoskeletal structures have a longer growth period than neural ones * Newborn: Conus medullaris at level of L3/L4 * Adult: Conus medullaris at level of L1/L2

Question 26

What is the position of the spinal nerves in relation to the vertebral column

Answer 26

Only spinal nerves of the cervical region are level with their respective vertebrae * Spinal nerves of the lumbar and sacral regions deviate strongly from their vertebral levels and form the Cauda equinae * In the lumbosacral region, the spinal nerves run through the lumbar cistern

Question 27

Describe filum terminale

Answer 27

Filum terminale (= extended strand of pia mater) which emerges through the arachnoid mater and attaches to the sacrum, at S2 level, surrounded by strand of dura mater, which attaches there as well. * The extension of dura and arachnoid mater to level of S2 forms a large forms a large subarachnoid space = lumbar cistern in that area, which is a reservoir for CSF

Question 28

What is the clinical relevance for the spinal cord ending at L1

Answer 28

The termination of the spinal cord at level L1 has clinical relevance: * The subarachnoid space and the lumbar cistern are “easy” access points (either lumbar or sacral) for: * Samples of CSF * Introduction of contrast agents (radiology) * Administration of anaesthetic and analgesic blocks

Question 29

Describe spinal anaesthesia

Answer 29

An anaesthetic agent is injected into the subarachnoid space, into the cerebrospinal fluid * Using a “heavy weight” agent, distribution up or down the spine and unilateral administration can be achieved * Only small amounts of agent needed, fast acting (< 5 minutes) * Is usually not administered above the level of L1 (danger of spinal cord damage) * Suitable for surgical procedures of the lower abdomen, pelvis and lower limbs

Question 30

How does epidural anaesthesia work

Answer 30

Agent is placed in the epidural space, no meninges are punctured * Pain relieve not as fast as spinal anaesthesia * Theoretically applicable everywhere on the spine * Larger amounts of agent fluid needed * Catheter can be inserted for “top-up” * Does not result automatically in a neuromuscular block – important when used in labour pain control

Question 31

How does blood supply to the spine work

Answer 31

Spinal cord and spinal nerve root supply: * From 1 anterior and 2 posterior spinal arteries, arising from the vertebral arteries (cervical region) * In the thoracic and lumbar region, the spinal arteries are supplied via the segmental arterial branches: thoracic = posterior intercostal arteries, lumbar = lumbar arteries. These are connected to the spinal arteries via radicular arteries Vertebral and intervertebral disc supply: * Segmental spinal arteries - cervical = vertebral arteries, thoracic = posterior intercostal arteries, lumbar = lumbar arteries give off periosteal arteries * Periosteal arteries supply the bone tissue and - via a network of metaphyseal anastomoses - the intervertebral discs

Question 32

Describe blood drainage of the spine

Answer 32

External venous plexus * Located within the muscles lying posterior to the transverse processes, spinous processes, articular processes and the laminae of the vertebrae Internal venous plexus * Located within the vertebral canal but outside of the dura mater (i.e. between dura mater and ligamentum flavum) * Drains blood from vertebral bodies and spinal cord * Exits with the spinal nerves through the intervertebral foramina and connects with external venous plexus Drainage to segmental veins of the body wall: cervical = vertebral veins, thoracic = posterior intercostal veins, lumbar = lumbar veins Blood flow is multidirectional - cancers of the pelvis and abdomen can spread into the thorax this way

Question 33

Describe injuries to the intervertebral disc

Answer 33

* Disc herniations: The nucleus pulposus herniates (fully or partially) through a rent in the outer layers of the annulus fibrosus * A herniation of the nucleus pulposus can occur in any direction but is mostly concentrated in postero-lateral positions due to the position of the posterior (and anterior) longitudinal ligament(s) * The nucleus pulposus is still confined within the annulus fibrosus * Most minor herniations/bulges heal within several weeks * Disc protrusions: Can develop from a previously existing disc herniation, where the outermost layers of the annulus fibrosus are still intact. When these layers rupture, disc material can protrude into the vertebral canal, particularly when under pressure

Question 34

What reflexes are indications of their spinal nerve roots

Answer 34

Biceps jerk - C6 * Triceps jerk - C7 * Knee (quadriceps tendon) jerk - L3 (L4, L2 admixture) * Ankle (Achilles tendon) jerk - S1 (L5 admixture)