Neurosystem: Vertebral Column and Spinal Cord Flashcards
Which part is the lamina of the vertebra?
Between the spinous process and the transverse process
Which part is the pedicle of the vertebra?
Between the transverse process and the vertebral body.
What name is giving to the joints between the articular facets of adjacent vertebrae? (i.e. between superior articular facet and inferior)
What type of joint is it?
Zygapophysial joints- synovial
Describe some distinctive features of cervical vertebrae.
Triangular vertebral foramen
Short,
Square/rectangular vertebral body
Transverse foramina in the transverse processes
Bifid spine (except C1 and C7)
Atlas and axis (C1 and C2) are specialized for movement
Facets are most horizontally orientated
Describe some distinctive features of thoracic vertebrae.
Bigger than cervical vertebrae
Circular vertebral foramen
Heart shaped vertebral body
Spinous process pointing sharply downwards
Transverse costal facets (for rib articulation)
Describe some distinctive features of lumbar vertebrae.
LARGE Articular facets are angled vertically to limit movement
Thin, long transverse processes (except L5)
Triangular vertebral foramen
Blunted, short spinous processes
Cylindrical vertebral body
Articular facets are orientated more vertically
How many bones fuse to form the sacrum?
5
Describe the structure of the sacrum.
Concave anterior surface
Triangular in shape
L shaped articular facets (for articulation with pelvic bones)
No spinous processes
How many bones fuse to form the coccyx?
3-4
Vertebral arches and canal are absent
What two types of joint are found between vertebrae?
Symphyses (cartilaginous)– between adjacent vertebral bodies
Synovial Joints – between articular processes
How many joints are there between two typical vertebrae?
6
- 2 symphyses (above and below)
- 4 synovial joints (2 superior and 2 inferior)
Between which vertebrae do you find intervertebral discs?
C2-S1
There is no intervertebral disc between C1 and C2 (you instead get atlanto-axial joint capsules)
What are the two parts of the intervertebral disc?
What is the function of the disc?
Nucleus pulposus
Annulus fibrosis
Functions:
- Allow for shock absorption
- Allow types of movement of the spine especially when combined
Describe how problems with the intervertebral disc can lead to potential clinical problems.
Degenerative changes in the annulus fibrosus can lead to herniation of the nucleus pulposus, which can then impinge on spinal nerves or the spinal cord.
The extent of symptoms is determined by how much the nerve is compressed.
Name the two ligaments that rung along the length of the vertebral bodies from the skull to the sacrum.
Anterior and Posterior Longitudinal Ligaments
Which ligament is typically damaged in whiplash?
Anterior Longitudinal Ligament
What is the name given to the upper part of the posterior longitudinal ligament going from C2 to the skull?
Tectorial Membrane
Which ligament is pierced in lumbar puncture and where is it positioned relative to the vertebral bodies?
Ligamentum flavum – found between the laminae of adjacent vertebrae.
it is yellow in colour
Name the triangular sheet-like structure found in the upper vertebral column. Where is it attached?
Ligamentum nuchae – attached from C7 (spinous process) to the occipital bone
What is continuous with the ligamentum nuchae and which part of the vertebrae is this attached to?
Supraspinous ligament.
It is connected to the spinous processes from C7 to the sacrum/coccyx
Which ligament lies between adjacent spinous processes?
Interspinous ligament
What are the three categories of muscles in the back and which muscles fall into each of these categories?
Superficial:
- Trapezius
- Latissimus dorsi
- Levator scapulae
- Rhomboid minor
- Rhomboid major
Intermediate:
- Serratus posterior superior
- Serratus posterior inferior
Deep
- Spinotransversales
- Erector spinae
- Transversospinales
- Interspinales
- Intertransversarii
Describe the flexibility of the cervical spine in terms of flexion/extension, lateral flexion and rotation.
Cervical spine can comfortably flex, extend, laterally flex and rotate.
The articular surfaces between vertebrae are almost horizontal, so all these movements are possible.
Also, the neck has less surrounding tissue than other parts of the spine
Describe the flexibility of the upper thoracic spine (T1-T6).
NO flexion/extension
Some lateral flexion
Some rotation
The articular surfaces are almost vertical, which doesn’t allow for flexion/extension.
Describe the flexibility of the lower thoracic spine (T7-T12).
Some flexion/extension
Good lateral flexion
Good rotation
Describe the flexibility of the lumbar spine (L1-sacrum).
- NO rotation
- Good flexion/extension
- Good lateral flexion
No rotation because their articular surfaces are curled around the articular surfaces of the adjacent superior vertebrae, ensuring no rotation.
Describe the shape of the atlas (C1).
It has NO vertebral body
It consists of two lateral masses with an anterior and posterior arch
Describe the articulations of the atlas.
The two lateral masses articulate superiorly with the occipital condyles and inferiorly with the superior articular surfaces of C2
Describe the structure of the axis (C2).
It is a typical cervical vertebra with the body extended upwards to form the dens (odontoid process)
Which ligaments are attached to the dens?
The transverse ligament of the atlas keeps the dens in place, against the articular surface on the posterior surface of the anterior arch of the atlas.
Alar ligaments are attached to the superolateral surfaces of the dens and the medial occipital condyles. The alar ligaments prevent excessive rotation of the head.
There are also longitudinal fascicles of the cruciform ligament (this crosses over the transverse ligament of the atlas to form the cruciate ligament)
State 5 important vertebral landmarks and how you would identify them on an individual.
C7 – vertebra prominens
T3 – level of the medial end of the scapular spine
T7 – level of the inferior angle of the scapula
L2 – level of the lowest rib
L4 – level with the iliac crest
How many sacral vertebrae are there?
5 (fused)
How many coccygeal vertebrae are there?
1-4 (fused)
How many vertebrae are there in total?
30-33 depending on how many coccygeal vertebrae there are
Which layer of cranial dura mater is the spinal dura mater continuous with?
Meningeal layer of the cranial dura.
There is no periosteal layer of dura in the spinal cord
At what level does the dural sac narrow around the filum terminal internum?
S2.
The subarachnoid space terminates here
What space is present in the vertebral column that you don’t find in the skull?
what does this space contain
Epidural space
it contains:
- Connective tissue
- Fat
- Internal vertebral venous plexus
What is the arachnoid membrane and where does it end?
It is a thin, delicate membrane that is against but not adherent to the deep surface of the dura mater.
It ends at S2
What thin structures interconnect the arachnoid and pia mater?
Arachnoid trabeculae – these also suspend vessels in the subarachnoid space
What is the spinal pia mater?
A vascular membrane that firmly adheres to the surface of the spinal cord
What are the longitudinally oriented sheets of pia mater that you’d find on either side of the spinal cord?
where do they attach
Denticulate ligaments.
They arise from the pia matter and attaches to the arachnoid AND dura mater; hence anchoring the spinal cord
Where do these ligaments attach medially and laterally?
Medially – to the spinal cord
Laterally – form a series of triangular extensions that anchor through the arachnoid membrane to the dura mater
Why would you perform a lumbar puncture?
give details
To obtain some CSF (e.g. to test for meningitis, SAH, etc)
To inject spinal anaesthesia (into the epidural space) or subarachnoid
- Epidural- pain relief in pregnancy
- Subarachnoid- pain relief for c-section
- Caudal epidural- for severe back pain/sciatic pain
At which level would you perform a lumbar puncture?
L3/L4 in an adult
1 or 2 vertebral spaces lower in a child
Which ligament is pierced in lumbar puncture?
Ligamentum flavum
State some signs of cervical spine injury.
- Low blood pressure + high pulse
- Large erection (Custer’s last stand)
- Flaccid paralysis
- Large bladder and inability to micturate
What steps would you take in the on scene management of a potential C-spine injury?
Assume unstable fracture
Assume neck pain if unable to communicate neck pain
Use cervical collar and blocks to immobilize the neck
What steps would you take in the hospital management of a potential C-spine injury?
Take lateral and AP C-spine – if fracture,
Image with CT/MRI
Give steroids – could prevent the death of around 1 cm of spinal cord
Treat any other symptoms e.g. low BP
Why is lower back pain the most common form of back pain?
Lower spine is subject to increased stresses of weight-bearing so the lumbar region is most commonly affected.
We tend to abuse our backs, particularly when lifting heavy objects.
Extending the spine from the fully flexed position under a heavy load can inflame intervertebral joints or place unequal pressure on the intervertebral disks, leading to local joint pain and referred neurological pain, if there is also pressure on the spinal nerve
Additional attempts to rotate the spine at the same time creates extra stress on the lumbar joints.
State 3 common deviations in spinal curvature.
Give potential causes
Scoliosis = abnormal lateral curvature of the spine
Kyphosis = excessive outward curvature of the spine, causing hunching of the back
Lordosis = excessive inward curvature of the spine
Causes could be:
- Weight gain- prob scoliosis
- Pregnancy
- Osteoporosis- kyphosis
- arthritis
Explain the types of spinal curvatures and how they are different throughout lifecourse
Foetus and embryo- has only primary curvature
Adult has both:
- Cervical- secondary
- Thoracic- Primary
- Lumbar- secondary-
- Sacral- primary
Label this atlas
label this axis
Label this
what roots are the enlargements of the spinal cord
Cervical (~C3-T1)
Lumbar (~L1-S2)
Describe the discrepancy between spinal levels and vertebral levels
how is this useful clinically?
The vertebral level is NOT the same as the spinal level. E.g. vertebral level T12 is at the level of the lumbar spinal cord, i.e. the T12 spinal nerve moves downwards to come out below the T12 intervertebral foramen
When describing spinal cord injuries, use the last functioning SPINAL levels
what are the different spinal pathologies?
- Fractures of vertebral column
- Prolapsed intervertebral disc - sciatica
- Spondylosis (degeneration)
- Spondylolysis (stress fracture of pars interarticularis)
- Spondylolisthesis (forward displacement of vertebra)
- Spondylitis (inflammation of vertebrae)
- Spinal cord injury
N.B they can affect the cord itself or nerves coming out via the intervertebral foramen
what is the par interarticularis
the part between the superior articular process and inferior articular process
what are the factors affecting the severity of spinal nerve lesion
Loss of neural tissue
- Usually small if due to trauma but can be more extensive (e.g. metastases, degenerative disease)
Vertical level- the higher the lesion, greater the disability
Transverse plane- number of tracts involved
According to the ASIA impariment scale, what are the classifications of spinal cord injury? Explain them
Grade A- Complete
Grade B- Sensory incomplete
Grade C- Motor incomplete
Grade D- Motor incomplete
Grade E- Normal
An incomplete spinal injury can further be classified into other syndromes, what are they?
Brown-Sequard Syndrome
Anterior Cord Syndrome
Posterior Cord Syndrome
Conus Medullaris Syndrome
Cauda Equina Syndrome
Label this diagram (1)
label this diagram
what occurs in Degenerative cervical myelopathy
Spinal cord decompression in the neck caused by degenerative chnages in the spine
Most common cause of spinal cord dysfunction
Gradual onset
Symptoms- have both UMN and LMN lesion symptoms
- LMN symtpoms - at spinal level of arthropathy (occurs at synapse)
- UMN symptoms- at and below the spinal level
- progressive neck pain
- clumsiness with hands
If you suspect a p[t with atroke, what is the next Ixs you need and explain why?
what other Ixs can you do
CT head- more readily available
- Can distinguish whether it’s ischaemic (black )or haemorrhagic stroke (white blood )
MRI is gold standard but not readily available
CT head angiogram
What is the difference between UMN and LMN lesion of facial nerve palsy.
what are the other exam findings for this lesion?
UMN- forehead sparing and CONTRALATERAL weakness
LMN (Bell’s palsy)- no forehead sparing and ipsilateral weakness
draw the pathway for the facial nerve that is relevant for the facial nerve palsy
what Ixs can you do if pts has symptoms of Bell’s palsy?
There’s no need for imaging, diagnosis can be made clinically.
if there’s uncertainty- do:
- CT head to exclude stroke
- MRI for tumours
- Bloods- rule out Lyme disease (bacterial infection that can affect brain)
what is a cause of Bell’s palsy?
Ramsay’s Hunt syndrome- shingles of CN7
can check for it by looking for blisters in ears.
There are other infections
