5. Thoracic & Lumbar Spine Flashcards
how does the thoracic spinal column differ from the other parts of the spine
articulates with the ribs
how many thoracic ribs are there
12
what is the curvature of the thoracic spine
kyphosis (primary curvature)
what difference do you notice in the bodies and spinous processes between T1 and T12
T12 looks more lumbar in form - big squared body and thick short spinous process - as it needs to support more weight further down the column
continuum of size increase and form change from T1-12
what passes through the intervertebral foramina
spinal nerves
each thoracic vertebra articulates with the ribs via what joint type
multiple synovial costovertebral joints
how many typical vertebral body does each rib articulate with
2
how many individual synovial joints does a typical rib form with the vertebral column
3
why do the ribs have so many small synovial joints with the vertebrae
stability and movement
many small joints permits movement while also maintaining stability
which specific parts of the vertebrae do the ribs articulate with
body (superior hemi-facet) and the transverse process of their own vertebrae and body of vertebrae above (inferior hemi-facet)
what do you notice about the position in the thoracic column in terms of the atypical thoracic vertebrae
they are at the extremity of either end
in transition areas from one part of the spine to another
what is atypical about rib 1 and therefore T1
there is no Thoracic vertebrae superior to it therefore the rib cannot follow the usual pattern identified above of articulating across 2 bodies
Rob 1 consequently only has one facet on its head and only articulates with T1 which has a complete - not hemi - facet
why are T10-12 atypical in the way that they are
although there are vertebrae above the lower T vertebrae bodies end up so large like lumbar vertebrae that the ribs end up only articulating with their own level vertebra
what is the effect that the morphology of T12 has on the 12th rib
one facet on body and no transverse process so more movement and instability (which is good in many ways) and less likely to fracture (protecting the kidneys)
the winking owl face is indicative of what type of pathology
lytic bone tumor
what kind of articulations are in a cartilaginous joint
bone -> cartilage -> bone
what kind of articulations are in a synovial joint
bone -> joint space -> cartilage bone
what kind of articulations are in a fibrous joint
bone -> fibrous tissue -> bone
eg sutures in the skull
how many joints does each vertebrae form with its adjacent counterpart
what types are these joints and where are they between
3
2 are zygapophyseal joints between superior and inferior articular facets of adjoining vertebrae
1 intervertebral disc between the bodies of adjoining vertebrae
what type of joints are the zygapophyseal joints and what does this morphology allow for
synovial
small sliding movements in limited planes
the thoracic zygapophyseal joints lock together, when compared to those of the lumbar spine what does this say about the functionality of these 2 areas of the spinal column
thoracic = limited flexion/extension, more twisting and lateral bending
lumbar = more flexion/extension but almost no twisting or lateral bending
the intervertebral disc acts as which 2 things
joint and ligament
each IV disc is composed of what 2 components and what are these components made of
annulus fibrosus = concentric layers of collagen running in opposing directions to eachother
nucleus pulposus = jelly like
what type of joint is the IV disc
symphysis (fibrocartilagenous/secondary cartilagenous)
what type of joint are all midline joints
symphysis (fibrocartilagenous/secondary cartilagenous)
what are the functions of the IV discs
absorb compressive forces and allow slight movement between vertebral bodies
what 2 ligaments run the length of the spine
anterior and posterior longitudinal ligaments
what 2 structure do the anterior and posterior longitudinal ligaments attach to
vertebral bodies and IV discs
the anterior and posterior longitudinal ligaments both originate from where and run all the way down to where
occipital bone down to proximal sacrum
the anterior and posterior longitudinal ligaments tend to be thicker and width in which part of the spine
anterior = thicker and narrower in the thoracic region
posterior = thicker and broader in cervical and thoracic regions than lumbar
what role do the anterior and posterior longitudinal ligaments play in restricting movement of the spine
anterior = restricts extension of spine
posterior = restricts flexion of spine
anterior longitudinal ligaments attach to what structure of the spine
top and bottom of vertebral bodies
posterior longitudinal ligaments thicken near what structure of the spine
thicken near the IV discs
what secondary function do the anterior and posterior longitudinal ligaments provide
help prevent the anterior or posterior herniation of the IV discs
what is herniation caused by
when weight isnt applied directly vertically on the IV discs
the anterior longitudinal ligament is implicated in the development of which spinal condition
diffuse idiopathic skeletal hyperostosis
what happens in DISH
the anterior longitudinal ligament gets ossified along its course with other spinal ligaments
what happens in ankylosing spondylitis
inflammatory arthritis of the spine causes ossification of the IV disc peripheries
what is the difference between DISH and AS on the x-ray image
DISH = fusion lines across vertebrae on anterior aspect usually, easily seen on lateral radiograph
AS = lateral and posterior fusion across bodies as whole IV disc periphery is involved and SI joint fusion
bamboo spine in PA view and squaring of vertebral bodies in the lateral view appearance in an image is associated with which spinal condition
AS
how many vertebrae are there in the lumbar region
5
what features differentiate the lumbar from thoracic vertebrae
larger squarer bodies in lateral view
short and squared spinous processes
smaller transverse process
no articulation for ribs
what are lumbar vertebrae more specialised at doing in the spine
supporting weight
what kind of curvature does the lumbar spine have
lordosis (secondary curve)
the spinous processes of the lumbar region differ from the thoracic vertebrae for what reason
creates access path to spinal canal and therefore spinal cord
eg for lumbar puncture
the sacrum consists of ___ ____ ____ with the coccyx attaching ___
5 fused vertebrae
inferiorly
the sacral vertebra have lateral bodies that fuse to form the ___
alae
the sacrum foramina that the other vertebrae dont have is formed by the fusion of what
what is this foraminas name
fusion and alar formation
anterior and posterior sacral foramina
the sacral hiatus marks what
and what is this useful for clincially
the termination of the sacral canal
access to the spinal canal contents (eg sacral nerve blockers)
the sacrum has 3 joints which are these
one joint with L5 superiorly
2 with the pelvis laterally
what part of the pelvis does the alae articulate with
what is this joint called
iliac bones
sacroiliac joint
the sacroiliac joint is part ___ but mostly ___ and hence this allows for what
part synovial, mostly fibrous
allows for a little movement whilst predominantly maintaining a strong articulation
the spinal cord begins where and ends at which vertebral level
what is its end called
base of brain stem to L1/L2 Vertebral level
conus medullaris
below the conus medullaris are spinal nerves which emerge lower than L1/L2 level
where do these continue down to and what level of the spine do they emerge from
what is the name given to these nerves
down to sacral hiatus
emerge from L2-S5 and coccygeal branches
cauda equina
what are the 3 layers that surrounds the spinal cord
what are these layers called
meninges
outer dura mater
intermediate arachnoid mater
inner pia mater
what is the spinal cord bathed in
cerebrospinal fluid
where is the CSF found
what is the fluids purpose
in the subarachnoid space
protects and nourishes spinal cord
lumbar punctures are made to extract what from where
are they performed in the upper/lower lumbar spaces why is this? why is it not in the thoracic region
extract CSF from spinal canal
lower lumbar regions - below L2 - as theres less risk of damage around the cauda equina than spinal cord (smaller nerves get pushed aside more easily)
in the thoracic region there is no access to the spinal cord due to spinous processes
what pass through the intervertebral foramina of the thoracic and lumbar vertebrae
spinal nerve roots
how many thoracic and lumbar spinal nerves are there
thoracic = 12
lumbar = 5
what is the relationship of the spinal nerve roots to their respective vertebrae
each spinal cord emerges inferior to its respective vertebra
what are the 2 plexus that supply the lower limb and pelvis
the lumbar plexus and sacral plexus
out of the 2 plexus supplying the pelvis and lower limbs which one is the more proximal
lumbar plexus
what nerve roots form the lumbar plexus
T12, L1-4
the lumbar plexus is associated and forms within which muscles
psoas major
for the psoas which is more medial and which is more lateral in terms of major and minor
major = lateral minor = medial
which regions of the lower limb/pelvis does the lumbar plexus mostly supply
anterior thigh muscles and skin on anteromedial thigh and medial leg
what symptoms are expected from damaging the lumbar plexus
burning/numbness and muscular pain in the anterior thigh muscles and skin on anteromedial thigh and medial leg regions
the sacral plexus is made of which nerve roots
L4-5 and S1-4
where is the sacral plexus located in terms of the pelvis and sacrum
deep within the pelvis ontop of the sacrum
what does the sacral plexus supply
majority of the lower limb
where do the sacral nerve roots contributing to the sacral plexus emerge from specifically
anterior sacral foramina
which muscle does the sacral plexus form anterior to
piriformis
through which space do the sacral plexus nerves exit the pelvis
greater sciatic foramen
what is more common - lumbar or sacral nerve root injuries/compressions
why
lumbar as sacral spine is very immobile and stable so therefore less prone to OA changes/injuries that might cause nerve root compression
