Spine Flashcards
What is the structure of the cervical vertebra?
Body - has the joints of lushka, uncinate process posteriorly
2 pedicles
- superior articular process
- inferior articular process
- intervertebral foramen
2 transverse processes
- transverse foramen; from C6 - C1 will contain vertebral artery
Anterior tubercle
Posterior tubercle
2 lamina
bifid spinous process
What are the three joints in the C spine?
Zygopophyseal facet joint
- synovial joint; therefore has capsule
- in between the superior and inferior articular processes of adjacent vertebra
Intervertebral disc
- fibrocartilaginous joint
- Annulus fibrosis, nucleus pulposus
Uncovertebral joint
- in cervical vertebra
- between lushka’s joint in one vertebra + inferior surface of vertebrae above (uncinate processes + vertebral body)
What do the joints of the cervical vertebrae permit movement wise?
flexion and rotation of head
What are the ligaments involved with the cervical vertebra?
Anterior longitudinal ligament
posterior longitudinal ligament
ligamentum flavum
ligamentum nuchae
What is the artery associated with the cervical vertebra?
vertebral artery
What are the nerves associated with the cervical spine?
Spinal cord (runs in the vertebral foramen)
Intervertebral Foramina - spinal nerves, dorsal root ganglion
What are the key relations of the cervical vertebra?
At C6, the vertebral artery enters the transverse foramen
Cervical vertebra are unique in that they have uncovertebral joints
Anterior - anterior longitudinal ligament, longus capitus, pharyngeal constrictors
Posterior - ligamentum nuchae, suboccipital muscles
Lateral - anterior sclene, middle scalene, posterior scalene, brachial plexus
What are the anatomical variants associated with the vertebra - cervical and thoracic?
Hemi vertebra (lack of formation of vertebra so get a wedge shaped vertebra)
Block vertebra (2 vertebra fused together)
Butterfly vertebra (failure of fusion of two halves of vertebral body)
Posterior element fusion
Arcuate foramen (caused by calcification of atlantooccipital ligaments)
What are the transitional vertebra?
At the atlantooccipital joint - base of skull to C1 (atlantooccipital assimilation) so C1 and occiput is fused
at cervicothoracic junction - cervical rib
at thoracolumbar junction - lumbar rib
lumbosacral junction - lumborilsation of S1, sacralisation of L5
What are the variants within the ossicles?
Os odontium - the atlas (C2), has the dens (odontoid process) which can apppear as an ossicle.
Peristent ossiculum terminale - tiny ossicle above the top of the dens
Anterior arch of accessory ossicle
Oppenhemiers ossicle - lumbar spine ossicle with facet joints
Sesamoid ossicles of the nuchal ligament
What is the osteology / structure of a thoracic vertebra?
Superior demifacet
Inferior demifacet
Transverse process from the body of vertebra
-> articulates with the rib at the costotransverse joint
Pedicle
- superior articular process
- inferior articular process
- intervertebral foramen
Lamina
- with pedicle and lamina, it encloses the vertebral column
Spinous process
What are the joints involved with the thoracic vertebrae?
Intervertebral disc
- fibrocartilaginous joint
between adjacent vertebral bodies is the nucleus pulposis + annulus fibrosis
Zygopophyseal joint
- synovial joint
- between superior and inferior articular processes of vertebral bodies
Costovertebral joint
- this is where the rib head articulates with vertebral body facets
- synovial joint, radiate ligament between demifacets and rib head
Costotransverse joint
- where rib tubercle articulates with transverse process
synovial, costotransverse ligament (superior and lateral)
What are the ligaments involved with the thoracic vertebra?
Radiate ligament
costotransverse ligament
anterior longitudinal ligament
posterior longitudinal ligament
ligamentum flavum
interspinous ligament
supraspinous ligament
What are the various rib anomalies?
Bifid/forked, hypoplasia, cervical rib, lumbar rib, only 11 ribs
What is the gross anatomy of the lumbar vertebra?
Body - has 2 transverse processes
2 pedicles -
- superior articular process
- inferior articular process
Intervertebral foramen; transmit spinal nerve, DRG medial
Lamina and pedicles make vertebral column
- spinal cord + cauda equina
Spinous process
What are the joints involved with the lumbar vertebrae?
Intervertebral Disc
- fibrocartilaginous joint
- between adjacent vertebral bodies
- nucleus pulposus + annulus fibrosis
zygophyphophyseal joint
- synovial joint
- between superior and inferior processes of adjacent vertebra
What are the ligaments of the lumbar vertebra?
anterior longitudinal ligament
posterior longitudinal ligament
ligamentum flavum
interspinous ligament
supraspinous ligament
What are the muscles involved with the lumbar vertebra?
Psoas
Quadratus lumborum
erector spinae
What are the nerves involved with the lumbar vertebrae?
vertebral column
- contains spinal cord until T12 / L1, then it is the conus medullaris, cauda equina
- intervertebral foramen - transmits the relevant spinal nerve
What are the relations of the lumbar vertebra?
Laterally - psoas, quadratus lumborum
L5 is the largest lumbar vertebra
What is the gross anatomy of the sacrum?
Wedge shaped bone at the bottom of the spine
Made of 5 fused vertebra
Articulates laterally with iliac bones, inferiorly coccyx, superiorly lumbar
What are the different parts of the sacrum?
Base - superior articular facet only
Body -
2 sacral ala (wings) - for iliac bones
central canal - transmits sacral N, coccygeal roots, filum terminale
foramina for transmission for spinal nerves -
4 anterior - pelvis
4 posterior - dorsal
median sacral crest - posterior
apex - articulates with coccyx
What are the joints involved with the sacral vertebrae?
intervertebral disc
- fibrocartilaginous joint
- between L5 and sacrum base
- annulus fibrosis + nucleus pulposus
zygophophyseal joint
- between the superior and inferior articular facets of vertebrae above and below
sacroiliac joint
- synovial joint
- sacroiliac joint
sacrococcygeal joint
- sacral apex to coccyx
What are the ligaments involved with the sacrum?
Anterior longitudinal ligament
Posterior longitudinal ligament
Ligamentum flavum
Sacroiliac ligament
Sacrococcygel ligament
Sacrotuberous ligament
Sacrospinous ligament
Iliolumbar ligament
What muscle is involved with the sacrum?
piriformis
What are the nerves involved with the sacrum?
Sacral and coccygeal nerve roots, travelling through central canal, so S1 - S5 are key
Filum terminale
What are the relations to the sacrum?
anterior - median sacral artery
lateral sacral artery
median sacral vein
sacral plexus
rectum S3 - S5
What are the anatomical variants of the sacral vertebra?
Sacralisation of L5
Lumbarisation of L1
Where does the iliolumbar ligament run from?
Tip of the iliac crest to the transverse process of L5
Quadratus lumborum arises from it
What is the L4-L5 vertebral disc?
Structure which sits between the L4-L5 vertebral bodies
Functions as a shock absorber
What is the gross anatomy of the L4-L5 intervertebral disc?
Contains a nucleus pulposus
peripheral annulus fibrosis
attached anteriorly to the anterior longitudinal ligament
attached posterior to the posterior longitudinal ligament
Is one of the joints of the vertebrae
What are the relations of the L4-L5 intervertebral disc?
bifurcation of the common iliac artery (L4 - L5) (anterolateral)
anterior longitudinal ligament (anterior)
ureter (anterolateral)
posterior
posterior longitudinal ligament
cauda equina
vertebrae
lateral
transverse processes
iliopsoas
What is the arterial and venous supply of the intervertebral disc?
Is avascular.
Does not have a vascular supply - recieves nutrition from diffusion from the intervertebral endplates
What is the nerve supply of the intervertebral discs?
peripheral annulus fibrosus is innervated by branches of dorsal root ganglia
What are the muscles / ligaments / fascia involved with the intervertebral discs at L4 - L5?
anterior longitudinal ligament
posterior longitudinal ligament
What is the gross anatomy of the atlas?
C1
No body
anterior ARCH
- has an anterior tubercle for attachment of the anterior longitudinal ligament
- facet on the inner surface for dens articulation
Posterior ARCH
- for ligamentum nuchae
Transverse process
- contains vertebral artery - is a horizontal running foramen
Superior articular process
- for occipital condyle
Inferior articular process
- for axis
Joints
- for atlanto occipital, atlantoaxial
What is the atlantooccipital joint?
synovial joint
between the superior articular facet of the atlas, and the occipital condyle of skull
vertebral A runs posterior to atlanto occipital joint (V3 segment)
What is the atlantoaxial joint?
the joint between C1 (atlas) and the C2 vertebra (axis)
has 2 components
dens of axis / anterior neural arch (synovial)
and the facet joint. (synovial)
What are the ligaments involved in the atlantoaxial joint?
Cruciform ligament (transverse and longitudinal ligament)
Alar ligament
Apical ligament
Tectorial membrane
Accessory atlantoaxial ligament
Also the anterior longitudinal ligament
posterior longitudinal ligament
ligamentum flavum
What are the anatomical variants associated with the atlantoaxial joint?
accessory ossicle of anterior arch of atlas
anterior arch non union - looks like a jefferson fracture
posterior arch non union
Describe the gross anatomy of the axis
It is an atypical cervical vertebra
It has a body
Dens - facet anteriorly: for articulation with anterior arch atlas
facet posteriorly - for articulation with cruciform ligament
transverse process
- for vertebral artery V2 segment
Lateral masses
- superior articular process
- inferior articular process
pedicle
lamina
spinous process
What is the joint between the axis and c3?
synovial joint
superior articular facet of axis, and inferior facet of atlas
What is the artery associated with the atlantoocipital joint?
V2 runs through transverse foramen
What is the nerve supply of the atlantooccipital joint?
Vertebral foramen - contains spinal cord
intervertebral foramen - contains spinal nerves and dorsal root ganglia medially
What are the bones involved in the atlanto occipital joint?
Atlas
Occipital condyles of the skull
Axis (via dens) - via cruciform ligament, alar ligaments, apical ligaments
IT IS A SYNOVIAL JOINT
has hyaline cartilage, synovial membrane, fibrous capsule
What movement does the atlanto occipital joint allow?
Forward flexion and extension
What are the muscles involved with the atlanto occipital joint?
rectus capiitis posterior minor
superior obliqus capitis
inferior obliqus capitis
rectus capitis
splenius capitis
What are the key relations of the atlanto occipital joint?
Superior: foramen magnum, brainstem
Inferior: axis
Medial: spinal cord
Lateral: vertebral arteries (V3 segement, leaving foramina to puncture dura to enter foramen magnum)
Anterior: oropharynx, longus colli / capiitis
Posterior: ligamentum nuchae
What are the joints involved in the lumbosacral articulations?
Intervertebral disc - between L5 and sacrum superiorly
Secondary cartilaginous joint
- ALL, PLL, ligamentum flavum, intervertebral disc
Where is the zygopophyseal joint in the lumbosacral articulation?
Between L5 inferior articular process and S1 superior aritcular process
Synovial - hyaline cartilage, synovial membrane, capsule
Describe the sacroiliac joint in the lumbosacral articulation?
Between the sacrum + ilium
Synovial -
joint capsule (as synovial joint)
iliolumbar ligament
sacroiliac ligaments
sacrotuberous ligament
Describe the sacrococcygeal joint in the lumbosacral articulation?
Between sacral apex and base of coccyx
Secondary cartilaginous
- anterior sacrococcygeal ligament (extension of ALL)
- posterior sacrococcygeal ligament (extension of PLL)
- sacrotuberous
- sacrospinous
What is the function of the spinal cord?
Carries important nerve ascending and descending tracts
Involved in spinal reflex arcs
What is the gross anatomy of the spinal cord?
Is a thick mass of grey + white matter tracts
- grey matter central, white matter peripheral
- surrounded by spinal meninges - thecal sac
What do the spinal meninges consist of?
Dura, pia, arachnoid mater
(spinal meninges blend with epineurium of spinal nerves)
there are two enlargements
- cervical bulge: for brachial plexus / cervical plexus
- lumbar bulge: for lumbosacral plexus
Central canal - filled with CSF - continuous with brain ventricular system
What are the contents of the spinal cord?
afferent tracts - sensory: spinothalamic, posterior column, medial leminiscal
efferent tracts - corticospinal
intervneurons are involved in spinal arcs
What is the course of the spinal cord?
origin: it is continuous superiorly with the medulla
runs in the vertebral column and will be divided by vertebral levels
Termination
conus medullaris
- in neonate L3
- in child L2/3
- in adult L1/2
each segment has a spinal nerve; which exits out of the intervertebral foramen
What is the arterial supply of the spinal cord?
Anterior spinal artery (comes off the intradural part of the vertebral A)
Posterior spinal artery (comes off PICA or VA)
Arterial vasocorona (anastomoses between the anterior spinal + posterior spinal A)
Radicular arteries
Artery of adamkiewicz
What is the artery of adamkiewicz?
dominant radicular artery
provides blood supply to anterior spinal artery below T8
usually from the left
comes off at the level of 9th + 12th intercostal A
What is the venous drainage of the spinal cord?
Mimics the arterial supply
- anterior spinal vein
- posterior spinal vein
- anterior and posterior radicular veins
- internal vertebral venous plexus (anterior / posterior)
What is the nerve supply of the spinal cord?
Spinal nerves + cauda equina
What are the muscles/ligaments /fascia involved with the spinal cord?
filum terminale
What are the variants associated with the spinal cord?
Tethered cord
conus medullaris
conjoined nerve roots
ventricularis terminalis
What are the two main pathways for sensory information to the cortex?
2 most important ascending pathways use a 3 neuron system to convey information from sensory receptors to the cortex.
Dorsal column - medial leminiscal
fine touch, proprioception, vibration, pressure (decussates at level of brain stem)
Anterolateral - spinothalamic
pain, tempreature, crude touch and some proprioception (decussates at spinal cord level)
What is the important descending pathway in the spinal cord?
It is the corticospinal
Only uses 2 neurons (an upper motor neuron) which is entirely in the CNS and a lower motor neuron which leaves at the segment of the spinal nerve
Corticospinal decussates at the brainstem like the dorsal column medial leminisical pathway
What is the course of neurons in the dorsal column - medial leminiscus tract?
1st order neuron ascends in the dorsal column, the decussates in the medulla, continues upwards towards the thalamus in the medial leminiscus
Will also use corona radiata + go to post central gyrus
What is the course of the spinothalamic - anterolateral tracts?
spinothalamic / anterolateral tracts enter, synapse and then decussate immediately and then head to the ventral posterolateral nucleus of thalamus
Will also use corona radiata + go to post central gyrus
What is the course of the neurons in the corticospinal tract?
Starts at precentral gyrus ->
posterior limb of internal capsule ->
cerebral peduncles of midbrain ->
decussate at the pyramids of the medulla
descend in the corticospinal tract and synapse at the level they will leave at
followed by going to the
interneuron and then third order neuron (ventral root)
Motor / efferent pathways use the ventral root
Describe the dorsal column / medial leminiscal pathway
Role: fine touch, proprioception, pressure, vibration
1st order neuron, synapses with the cell body in the dorsal root ganglia. and immediately ascends in the dorsal column. 2nd order neuron is in the medulla…
Synapses in the medulla and decussates in the medulla, ascends from the medial leminiscus to thalamus
Thalamus ventroposteriorlateral. nucleus synapses
3rd order neuron leaves by corona radiata of internal capsule (from thalamus to post central gyrus)
Goes to post central gyrus of parietal lobe
What is the pathway of the neuron in the spinothalamic tract?
Role: pain, tempreature, gross touch
1st order neuron (cell body in dorsal root ganglion) - enters in spinal cord segment via dorsal root
immediately synapses and decussates at the spinal cord segment + synapses
2nd order neuron ascends in the anterolateral tract of the spinal cord to the thalamus
thalamus VPL + synapses
3rd order neuron leaves by corona radiata of internal capsule
goes to post central gyrus of parietal lobe
What is the neuronal pathway of the corticospinal tract?
Role: major descending pathway from brain to the skeletal muscles.
1st order neuron: cell body in precentral gyrus
Fibres descend in the corona radiata, go through posterior limb of internal capsule, cerebral peduncles of midbrain, pyramids of the medulla,
Descend in the spinal column as the corticospinal tract
At the segment they are going to leave, will synapse. 2nd order neuron in spinal cord segment, third order neuron will leave via ventral root
(second order neuron is an interneuron)
What is the corticospinal tract?
It is the major descending pathway for motor control from brain to skeletal muscle
What is the gross anatomy of the corticospinal tract?
Origin - first order neuron descends from the frontal lobe pre central gyrus
goes to the corona radiata,
posterior part of the internal capsule
cerebral peduncles of midbrain
descends through brainstem
pyramids of medulla - decussates
and descends in the corticospinal tract
at segment that they are going to leave at - they synapse
Then second order interneuron at spinal cord segment, and third order neuron, which leaves at same segment and exits via the ventral root
What is the function of the spinothalamic / anterolateral tract?
Responsible for pain, tempreature, gross touch
What is the gross anatomy of the spinothalamic tract?
1st order neuron - whole cell body in the dorsal root ganglia enters via the dorsal root
Synapses and decussates at the spinal level, second order neuron will ascend in the anterolateral tract of the spinal cord
Thalamus (ventroposterior nucleus) will synapse
3rd order neuron will then form and from thalamus will travel to the corona radiata and to the post central gyrus in the parietal lobe
What is the function of the medial leminiscal tract?
responsible for fine touch, proprioception, vibration
What is the gross anatomy of the medial leminiscal tract?
1st order neuron (cell body in dorsal root ganglia) which enters via the dorsal root
ascends in the posterior column of spinal cord
decussates in the medulla
second order neuron ascends through brainstem in the medial leminiscal tract to VPL of thalamus. Then synapses
3rd order neuron goes to the corona radiata (of internal capsule) and then to post central gyrus and parietal lobe
What are the anatomical variants for the arterial supply to the spine?
Anterior spinal artery can come from vertebral artery or posterior inferior cerebellar artery
posterior spinal artery can come from vertebral artery or posterior inferior cerebellar artery
Radicular arteries
arterial vasocorona
artery of adamkiewicz
What is the cauda equina?
It is the horses tail of lumbar/sacral/coccygeal nerve roots which hang inferior to the conus
What is the function of the cauda equina?
to transmit the lumbar, sacral and coccygeal nerve roots through the vertebral column
Where does the cauda equina sit?
Inferior to the conus medullaris
neonate - L3
Child - L2
Adult - L1 / L2
What is the gross anatomy of the conus medullaris?
Marks the end of the spinal cord
Made of nerve roots
Enclosed in dural sac until S2
Filum terminale is inferior
runs in the vertebral column
What are the relations to the cauda equina?
Superior - conus medullaris
Inferior - sacral aperture
Lateral - intervertebral foramina, nerve roots, radicular artery, intervertebral / radicular vein
What is the arterial suppy of the cauda equina?
The radicular arteries (through the intervertebral foramina)
What is the venous drainage of the cauda equina?
Intervertebral veins
Internal venous plexus (both anterior and posterior)
What are the nerves contained in the cauda equina?
Spinal nerves of lumbar, sacral, coccygeal segments
What are the muscles / ligaments / fascia involved with the cauda equina?
Filum terminale
What is the anatomic variation of the cauda equina?
conus medullaris - changes with age
ventricularis terminalis - cystic structure at transition of conus - filum terminale
What is the sympathetic trunk?
It is a paired bundle of nerve fibres which run from skull base to coccyx
Essential part of the sympathetic autonomic nervous system
Sphlanchic nerves arise from it
Interacts with the spinal nerves
Where does the sympathetic trunk sit?
Is posterior which is lateral to vertebral bodies
Continuous superiorly with cervical sympathetic trunk
What is the gross anatomy of the sympathetic trunk?
It is located lateral to the vertebral bodies
covered by pleura or peritoneum
continuous superiorly with cervical sympathetic trunk
lateral to vertebral bodies and under median arcuate ligament of diagphram
terminates to be lateral to the vertebra
What does the sympathetic trunk contain?
Paravertebral ganglia
Ganglia along the trunk
What are the key relations of the sympathetic trunk?
It is lateral to the vertebral column
Runs underneath the median arcuate ligament of the diapghram
What is the arterial supply of the sympathetic trunk?
Branches of intercostal / lumbar / sacral arteries
Radicular arteries
What is the intervertebral foramina?
Lateral passageway where spinal nerves pass out from central vertebral column to the periphery
What is the gross anatomy of the intervertebral foramina?
Anterior - vertebral body, intervertebral disc
Posterior - lamina, ligamentum flavum, facet joint
Superior - pedicle of superior vertebra body
Inferior - pedicle of inferior vertebra body
Medial - spinal cord
Lateral - spinal nerves
What is the contents of the intervertebral canal?
Dorsal root ganglion - spinal meninges fuse just distal to DRG
spinal nerve
radicular artery
radicular vein
epidural fat
What is the lateral recess?
It is the space between the thecal sac and intervertebral foramen
What are the boundaries of the lateral recess?
Space between INTERVERTEBRAL FORAMEN + Thecal Sac
ANteriorly
Vertebral body
Intervertebral disc
Posterior longitudinal ligament
Posterior
Ligamentum flavum
Lamina
Medial
thecal sac
Lateral
Pedicle
Facet joint
Intervertebral foramen
Contents
nerve roots
epidural vessels
fat
