Session 2: Vertebral Column and Spinal Cord Flashcards
Which part is the lamina of the vertebra?
Between the spinous process and the transverse process
What is the pedicle in the vertebra
Between the transverse process and the vertebral body
What name is giving to the joints between the articular facets ofadjacent vertebrae?
Zygapophysial joints
Describe some distinctive features of cervical vertebrae.
- triangular vertebral foramen
- short, rectangular body
- foramina transversaria (for vertebral arteries)
- bifid spinous process (except C1/C7)
- almost horizontal articular facets inf & sup
Describe some distinctive features of thoracic vertebrae.
- circular vertebral foramen
- large heart-shaped body
- long spinous process (projects inf)
- inf & sup costal facets on either side of body = articulate with rib
- transerve facets to articulate with rib tubercle
- vertical articular facets face post & ant
Describe some distinctive features of lumbar vertebrae.
- triangular vertebral foramen
- very large kidney-shaped body
- short & blunt spinous process
- very long transverse process
- rounded upper & lower facets = no rotation
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)
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 – 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?
Nucleus pulposus
Annulus fibrosus
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
spinal nerve below is affected
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 arm 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
Name the triangular sheet-like structure found in the upper vertebral column. Where is it attached?
Nuchal ligament – attached from C7 to the occipital bone
What it continuous with the ligamentum nuchae and which part of the vertebrae is this attached to?
Supraspinous ligament
It is connects to the spinous processes from C7 to the sacrum
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
State the origin, insertion and function of:
a. Trapezius
b. Latissimus Dorsi
c. Levator Scapulae
d. Rhomboid Minor
e. Rhomboid Major
a. Trapezius Origin – external occipital protuberance, cervical and thoracic spine Insertion – clavicle and scapula Function – elevate and rotate the scapula when the humerus is abducted b. Latissimus Dorsi Origin – T7 to sacrum + thoracolumbar fasica + posterior 1/3 of iliac crest Insertion – intertubercular sulcus of the humerus Function – extends, adducts and medially rotates the humerus c. Levator Scapulae Origin – transverse processes of C1-C4 Insertion – upper medial scapula Function – elevates the scapula d. Rhomboid Minor Origin – spinous processes of C7-T1 Insertion – medial border of scapula Function – adduct and elevate scapula e. Rhomboid Major Origin – spinous processes of T2-T5 Insertion – medial border of scapula Function – adduct and elevate scapula
Where are the erector spinae muscles found and what is their function?
Extend the vertebral column (stabilise and control movement)
Lie posterolaterally to the vertebral column between the spinous processes medially and the angles of the ribs laterally
Describe the flexibility of the different parts of the spine
Cervical = most flexible part of spine:
- horizontal zygapophyseal joints = good rotation
- less surrounding tissue = good flex/extend (+ lat)
Upper thoracic: ~ vertical zygapophyseal joints = no AP flexion/extension, limited lateral flexion & rotation
Lower thoracic: limited flexion/extension, good lateral flexion & rotation
Lumbar: large intervertebral discs = good flexion & extension; articular surfaces interlock = no rotation + very limited lateral flexion
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 theatlas.
Alar ligaments are attached to the superiolateral 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
At what level does the dural sac narrow around the filum terminale?
S2
What space is present in the vertebral column that you don’t find in the skull?
Epidural space
What does the epidural space contain?
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
Where does the subarachnoid space end?
S2
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 youfind on either side of the spinal cord?
Denticulate ligaments
Where do the denticulate 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?
To obtain some CSF (e.g. to test for meningitis)
To inject spinal anaesthesia (into the epidural space) for pelvis/ lower limb surgery
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? List spaces/membranes you pierce through when you perform epidural/CSF aspiration
skin → supraspinous - interspinous ligaments - ligamentum flavum (give felt) → epidural space → dura + arachnoid (pop/give) → into subarachnoid space = CSF should pass out
For epidural (slower & longer acting) anaesthesia stop at epidural space
Why would you never do a lumbar puncture in the case of raised intracranial pressure?
It will cause a sudden relieving of pressure, which could have brainstem herniation and death.
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?
Low 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 pressureon 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 & the normal curvatures
Primary (ant concave) = thoracic & sacral
Secondary (post convex) = cervical & lumbar
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
Summarise spinal blood supply
Post spinal arteries from PICA
Anterior spinal artery from vertebral (sup) and intercostal/iliac (inf)
Define: Spondolysis Spondylolysis Spondylitis Spondylisthesis
spondolysis (degeneration of vertebral column)
spondylolysis (broken pars interarticularis)
spondylisthesis (forward displacement of vertebra)
spondylitis (inflammation of vertebrae)
List three common types of spinal injury
- hyperextension (whiplash) injury - ‘tear-drop’ fracture and dislocation of vertebra & torn ant longitudinal ligament
- dislocation of cervical vertebrae
- excessive compressive force from occipital condyles to C1 = ‘Jefferson’ (burst) fracture on anterior/ posterior arches
What is the clinical significance of the internal vertebral venous plexus (in terms of cancer)?
Batson veins (venous plexus) connects deep pelvic veins with the internal vertebral venous plexus = possible route of metastasis of prostate, bladder or rectal cancer into to the spine (also infection)
