Session 2: 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 bod
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, square vertebral body Transverse foramina in the transverse processes Bifid spine (except C1 and C7) Atlas and axis (C1 and C2) are specialized for movement
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 to limit movement Thin, long transverse processes (except L5) Triangular vertebral foramen Cylindrical vertebral body
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 thespinal cord
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 art of the posterior longitudinal ligament going from C2 to the skull?
Tectorial Membrane
Which ligaments are pierced in lumbar puncture and where are they positioned relative to the vertebral bodies?
Supraspinous - between tips of spinous processes
Interspinous - between the spinous processes
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?
Ligamentum nuchae – 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
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 movement 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 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 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 this 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 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?
To obtain some CSF (e.g. to test for meningitis) To inject spinal anaesthesia (into the epidural space)
At which level would you perform a lumbar puncture?
L3/L4 in an adult 1 or 2 vertebral spaces lower in a child
Which ligaments are pierced in lumbar puncture?
Supraspinous
interspinous
Ligamentum flavum
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.
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
State the origin, insertion and function of Trapezius
- Origin – external occipital protuberance, cervical and thoracic spine
- Insertion – clavicle and scapula
- Function – elevate and rotate the scapula when the humerus is abducted
State the origin, insertion and function of 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
State the origin, insertion and function of levator scapulae
- Origin – transverse processes of C1-C4
- Insertion – upper medial scapula
- Function – elevates the scapula
State the origin, insertion and function of rhomboid minor
- Origin – spinous processes of C7-T1
- Insertion – medial border of scapula
- Function – adduct and elevate scapula
State the origin, insertion and function of rhomboid major
- Origin – spinous processes of T2-T5
- Insertion – medial border of scapula
- Function – adduct and elevate scapula
State the origin, insertion and function of serratus posterior superior
- Origin –C7-T3
- Insertion – upper border of ribs 2-5
- Function – elevates ribs 2-5
State the origin, insertion and function of serratus posterior inferior
- Origin – T11-L3
- Insertion – lateral inferior margins of ribs 9-12
- Function – depresses ribs 9-12 and prevents lower limbs from elevating when the diaphragm contracts
State the location and function of Spinotransversales
- Extensors and rotators of the head and neck
- The two spinotransversales muscles run from the spinous processes up to T6 and ligamentum nuchae, running superiorly and laterally
State the location and function of Erector Spinae and Transversospinales
- Extensors and rotators of the vertebral column
- Erector spinae lie posterolaterally to the vertebral column between the spinous processes medially and the angles of the ribs laterally
- Transversospinales run obliquely upward and medially from the transverse process to the spinous process
State the location and function of Interspinales and Intertransversarii
- These are short segmental muscles that are the stabilisers of the vertebral column
- Interspinales – pass between adjacent spinous processes
- Intertransversarii – pass between adjacent transverse processes
