Spine Flashcards
Ventral roots contain only which type of nerve fibres?
Efferent/motor
How many pairs of spinal nerves do we have?
31 pairs
Each individual axon is surrounded by a…
Endoneurium
Each nerve fascicle is surrounded by a…
Perineurium
The entire nerve is surrounded by a …
Epineurium
Spinal nerves leave the spinal cord via …
Intervertebral foramina
What spinal level is conus medullaris?
L2
What do we call it when only the spinal roots are travelling through the vertebrae and not the spinal cord?
Cauda equina
C1 - C7 exit …. the corresponding vertebrae
Above
Where does C8 exit?
Between vertebrae C7 and T1
T1-L5 exit … the corresponding vertebrae
Below
Define the spinal nerve root of an injury
The lowest level of full sensation and function
Dorsal roots contain only which kind of nerve fibres?
Afferent/sensory
How many vertebrae do we have?
33
How many cervical vertebrae do we have?
7
How many thoracic vertebrae do we have?
12
How many lumbar vertebrae do we have?
5
How many sacral vertebrae do we have?
5
How many coccygeal vertebrae do we have?
4
How many discrete single vertebrae do we have?
24
How many fused vertebrae do we have?
9
2 structures
What is the vertebral lamina?
The part of the vertebra that connects the transverse process to the spinous process
What is the vertebral pedicle?
The part of the vertebra that connects the transverse process to the vertebral body
Which ligament strengthens the intervertebral foramina?
Ligamentum flavum
What does the interlocking design of the vertebrae prevent?
Anterior displacement
What is the functional and structural classification of the vertebral joints?
Amphiarthrosis
Cartilaginous (symphysis)
What are the outer lamellae of the annulus fibrosus made of?
Collagen
What are the inner lamellae of the annulus fibrosus made of?
Fibrocartilage
Name some features of the annulus fibrosus
Avascular Aneural Surrounds nucleus pulposus Shock absorber Stronger than the vertebral body
Which part of the spine changes in size throughout the day?
Nucleus pulposus
What are the stages of a slipped disc?
Disc degeneration
Prolapse
Extrusion
Sequestration
Where does a slipped disc most commonly occur?
L4/5
L5/S1
Which direction does disc usually herniate in?
Posterolaterally
Why is a posterior herniation an emergency?
may cause spinal cord compression
Pressure on nerve roots leads to radiculopathy. What is radiculopathy?
Dermatomal sensory symptoms: paraesthesia and pain
Myotomal motor weakness
Pressure on the spinal cord leads of myelopathy? What is myelopathy?
Global weakness
Gait dysfunction
Loss of balance
Loss of bladder and bowel control
What defines the cervical vertebrae?
Smallest of discrete vertebrae
Bifid spinous processes (except C7)
Transverse foramen in transverse process (foramen transversarium)
Triangular vertebral foramen
What travels through the transverse foramen of cervical vertebrae? (Except C7)
Vertebral artery and vein
What does the C7 transverse foramen transmit?
Accessory vertebral vein
What is the name of the first cervical vertebra?
Atlas
What joints does the atlas make?
Atlanto-occipital
Atlanto-axial
Which joint permits nodding? (Flexion and extension)
Atlanto-occipital joint
Which joint permits shaking the head? (Lateral rotation)
Atlanto-axial
What makes the atlas vertebra different ?
No vertebral body
No spinous process
Widest cervical vertebra
What do we call the second cervical vertebra?
Axis
What are the 3 main features of the axis?
Odontoid process (or Dens)
Rugged lateral mass
Large spinous process
Which structures prevent horizontal displacement of the atlas on the axis?
Odontoid process (or Dens) Transverse ligament
What are the 2 types of axis fracture?
Hangman’s fracture
Peg fracture
Describe a Hangman’s fracture
Hyperextension of the head on neck
Axis fractures through pedicles
Forward displacement of C1 and body of C2 on C3
Significant spinal cord injury
Describe a peg fracture
Blow to the back of the head
Fracture through the Dens
What do we call a fracture of the atlas?
Jefferson’s fracture
Describe a Jefferson’s fracture
Fracture of the anterior and posterior arches of the atlas
Caused by axial load (diving into shallow water)
Typically causes pain but no neurological signs
Which spinous process is the longest?
C7
How does whiplash occur?
Cervical spine has a high mobility and low stability
Hyperextension and hyperflexion can occur and causes temporary contusion to the spinal cord
Which facets of thoracic vertebrae articulate with the head of the rib?
Demi facets on sides of vertebral body (T2-T8) Whole facets (T9-T10)
Which facets of the thoracic vertebrae articulate with the tubercle of the rib?
Costal facets on transverse processes
What structures does the sacrum articulate with?
L5
Ilium
Coccyx
Which parts of the spine would be classed as lordosis?
Cervical
Lumbar
What parts of the spine would be classed as kyphosis?
Thoracic
Sacral
Coccyx
Describe the spine of a foetus
Flexed in a single curvature - primary curvature
C-shaped
Kyphosis (concave anteriorly)
When does the cervical spine begin to lordosis?
When the young child begins to lift its head
When does the lumbar spine lose primary kyphosis?
During crawling
When does the lumbar lordosis develop?
When the child begins to stand and walk
Where does the centre of gravity pass through the vertebral column?
C1-C2
C7-T1
T12-L1
L5-S1
What is senile kyphosis?
Secondary curvatures of the spine begin to disappear
Continuous primary curvature reestablished
What is Scheuermann’s disease?
Uneven vertebral growth
Leads to increased kyphosis (usually thoracic)
Posterior border of spine longer than anterior border
What is scoliosis?
Lateral curvature of the spine
May be cosmetic, can lead to prominence of ribs and/or scapula and uneven ‘apparent’ arm and leg length
What 3 types of scoliosis can occur?
Primary (congenital)
Idiopathic
Secondary to a neuromuscular disease
What is kyphoscoliosis?
Pathological kyphosis and scoliosis combined
Asymmetric weakening of paraspinal muscles
Leads to: reduced lung capacity, pulmonary hypertension and spinal cord compression
Which 2 diseases are likely to lead to kyphoscoliosis?
Duchenne muscular dystrophy
Spinal muscular atrophy
What are the 2 main ligaments of the vertebral column?
Anterior longitudinal and posterior longitudinal
What ligaments is stronger: anterior longitudinal or posterior longitudinal?
The anterior longitudinal ligament is stronger
Where does the anterior longitudinal ligament run from and to?
Anterior tubercle of atlas to sacrum
What does the anterior longitudinal ligament prevent?
Hyperextension
Where does the posterior longitudinal ligament run from and to?
Body of axis to sacral canal
What does the posterior longitudinal ligament prevent?
Hyperflexion
Describe the ligamentum flavum
Between laminae of adjacent vertebrae (help form the intervertebral foramina)
Elastic fibres
Stretched during flexion
Describe interspinous ligaments
Unite spinous processes of adjacent to vertebrae
Sheets of fibrous tissue
Relatively weak
Well developed in lumbar region to confer stability in flexion
Describe the supraspinous ligament
Joins the tips of adjacent spinous vertebrae Strong bands of fibrous tissue Lax in extension Tight in flexion Starts at C7
What do we call the ligament that attaches the external occipital protruberance to the cervical vertebrae?
Ligamentum nuchae
What is the role of the ligamentum nuchae?
Maintains secondary curvature of cervical spine
Supports the head
Major site of attachment for neck and trunk muscles
What are the sites for lumbar puncture?
L2/3
L3/4
L4/5
(After the conus medullaris)
Where do we take spinal fluid from?
Subarachnoid space
What happens to annulus fibrosus as you age?
Gets thinner posteriorly
