Spine Flashcards
know how these locations dorsal root ganglia, spinal nerves, and peripheral nerves.
what 2 feature of spinal cord form synovial joint to allow movement of spine?
the articular process (up and down)
which vertebrae form the most mobile part of the spine? why?
The Cervical
. -bc o f the curved shape of their bodies>> flexion and extension
-bc of the shallow slope of their oracular surface> later flexion
what r the movement that can can occur in the lumbar spine?
flexion, extension & later flexion to either side.
what r the ligament of the spine
Ligamentum** **flavum
- Yellow in colour: due to “elastic fibres”
- Between laminae of adjacent vertebrae
- Stretched during flexion of the spine
Interspinous ligaments
- Relatively weak sheets of fibrous tissue
- Unite spinous processes along adjacent borders
- Well developed only in the lumbar region (stability in flexion)
- Fuse with supraspinous ligaments
Supraspinous ligaments
- Tips of adjacent spinous processes
- Strong bands of white fibrous tissue
- Lax in extension
- Tight in flexion (mechanical support for vertebral column)
what is ligament flavum?
“yellow ligament” so thick, made of yellowish fibroelastic ligament. (the leastin make sit yellow)
Limits hyper-flexion
important when performing a lumbar punture
Between laminae of adjacent vertebrae
what prevents the vertebrae from slipping away from each other?
the fact their upper articular surface faces upwards and the lower faces downwards, so the lock on each other.
what r the routes of the sciatic nerves?
L4-S3
largest single nerve in the human body
what is Kyphosis?
.
Name and describve the fucntion of structures
Intervertebral disk consists of:
1) annulus fibrosis (onion skin) made of layers (tension resistant sheath)
External fibrous ring that consists of an inner and outer zone
the outer zone is fibrous sheath that gives high tensile strength and made up of concentric LAMELLAE type 2 collagen.
every layer (onion sheet) of collagen lines up in a different way.
In any particular movement we r in, some of these sheets will be in tension and some of these sheets will be relaxed> BUT they will proved a CONSTANT PRESSURE to the nucleus itself.
it transforms compressive forces into tensile forces.
2) nucleus pulpus
gelitinous core,(lots of GAGS) it functions as a “water cushion” to absorb transient axial loads on the disk. 80-85% water
they both act as effective shock absorbers where rhey can distribute pressure uniformaly over the adjacent vertibral end plates.
what is lordosis
.
what is spina bifida?
Spina bifida is part of a group of birth defects called neural tube defects. The neural tube is the embryonic structure that eventually develops into the baby’s brain and spinal cord and the tissues that enclose them.
Describe the pathophysiological processes that result in diminution of height and loss of secondary curvature of the spine in old age?
With increasing age,
annulus fibrosis undergo degeneration (because of wear and tear).
nucleus pulposus loses its turgor and becomes thinner because of dehydration (failure of imbibition) and degeneration.
These degenerative processes account for some loss of height. Disc atrophy returns the curvature of the spine to the primary curvature of the newborn.
State four factors that contribute to the stability and mobility of the vertebral column.
- The thickness and compressibility of the intervertebral discs
- The shape and orientation of the intervertebral facet joints
- The tone of the back muscles
- The resistance of the ligaments of the vertebral column.
Describe the movements of the vertebral column that can occur in each of the cervical, thoracic and lumbar regions. Explain what anatomical features determine the movements possible in each region.
Cervical:
Thoracic:
Lumbar:
Cervical: Rotation only.
Thoracic: Flexion, extension, lateral flexion, rotation.
Lumbar: Flexion, extension, lateral flexion, tiny amount of rotation
What is neurogenic claudication?
.
What is spondylolisthesis? How does it differ from spondylolysis?
.Spondylolysis and spondylolisthesis are common causes of low back pain in young athletes.
Which part of the vertebra is known as the pars interarticularis?
Ligaments of spine
Ok
Describe the 4 stages to a disk herniation
Disc Degeneration: chemical
changes associated with aging
cause discs to dehydrate and
BULGE
• Prolapse: protrusion of the nucleus
pulposus with slight impingement
into the spinal canal (contained)
• Extrusion: nucleus pulposus
breaks through annulus fibrosus,
but remains within the disc space.
• Sequestration: nucleus pulposus
breaks through annulus fibrosus
and separates from the main body
of the disc in the spinal canal.
A 3 year old girl is admitted with fever, tachypnoea (rapid breathing), photophobia, neck stiffness and a non-blanching rash. Meningitis is suspected. A lumbar puncture is performed.
Q1. Suggest a suitable vertebral level at which the needle should be inserted. Explain the rationale for your choice.
Q2. State the structures through which the needle will pass, in order from the skin to the subarachnoid space.
PALPATE THE ILIAC CREST AND BRING UR HANDS TO THE MIDLINE, this equates for the L4,5 disks.
L2/3), L3/4 or L4/5 (after the conus medullaris so only mobile
spinal nerve roots not cord; least chance of neurological damage)
(Skin), subcutaneous tissue, supraspinous ligament, interspinous
ligament, ligamentum flavum, epidural fat and veins, dura mater,
arachnoid mater, (subarachnoid space)
What is spondylolisthesis? How does it differ from spondylolysis?
spondylolysis is defect or stress fracture in the pars interarticularis of the vertebral arch. (spotty the dog’s neck)
Spondylolisthesis is a forward or backward slippage of one vertebra on an adjacent vertebra.
where does the vast majority of spondylosis occur?
The vast majority of cases occur in the lower lumbar vertebrae (L5), but spondylolysis may also occur in the cervical vertebrae.
what has happened here?
Forward slippage of an upper vertebra on a lower vertebra is referred to as anterolisthesis,
(while backward slippage is referred to as retrolisthesis.)
how many vertebrae do we have in our body?
which area is the most mobile? immobile & why?
33 vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, 4 coccygeal.
24 separable vertebrae
- Mobile – Cervical and Lumbar
- Relatively Immobile – Thoracic (bc it has the ribs attachted to it)
Fused Vertebrae
•9 vertebrae fused to give 2 innominate structures
– Sacrum (fusion of 5 vertebrae)
– Coccyx (fusion of 4 vertebrae)
Fucntions of the vertebral column
-
- Central bony pillar of the body.
- Supports the skull, pelvis, upper limbs and the thoracic cage.
- Protection of the spinal cord and the cauda equina
- Movement - Highly flexible structure of bones, intervertebral discs and ligaments
- Haemopoiesis – red marrow
Label
yippee
know these anatomy
The conus medullaris, cauda equina, filum terminale, spinal nerve roots,
Vertebral bodies ________ in size inferiorly as compression forces increase
Increase
what is the function of the sacral vertebrae in relation to the body’s central of gravity?
Sacral vertebrae: is fused, widened & concave anteriorly to transmit the weight of the body through pelvis to legs
describe the structure of a typical Lumbar vertebrae
General characteristics:
- Kidney shaped vertebral body
- Vertebral arch posteriorly
- Vertebral foramen: for spinal cord and meninges
Vertebral arch:
Gives rise to 7 processes
•x1 Spinous Process
•x2 Transverse Process
•x2 Superior Articular Process •X2 Inferior Articular Process
what is this structure? describe it? and the bone composition
Usually the largest part of the vertebra
10% Cortical Bone
90% Cancellous Bone (we r lighter, hemopoesis)
-Usually the main weight bearing
80% of the body weight passes through the vertebrae body
80% of the body weight passes through the _______
Vertebrae Body
what connects the transverse process with the spinous process?
the lamina
what is a Laminectomy
removal of spinous processes and lamina to increase the space for the nerves themselves.
- is surgery that creates space by removing the lamina — the back part of the vertebra that covers your spinal cana
Describe the articulation of the Sacrum
Sacrum consists of 5 fused vertebrae
Articulates with L5 superiorly ,
ilium laterally
coccyx inferiorly
Label these ligaments
vertebral body ligaments:
- Anterior Longitudonal ligament (stronger!) bind to vertebrae by uniting with periosteum -limits hyper extensions
- Posterioir longitudonal ligament -limits hyper extensions
Vertaberal arch ligament
- Ligamentum Flava
- Interspinous ligament
- Supraspinous ligaments
- intertransverse ligaments
what is this
Vertebral foramen
what is this area circled here?
decribe it
a facet joint, (it is a synovial joint!)
formed by the superior and inferior articulaing process.
it prevents anterior displacemnt of vertebrae.
the orientation of the facet joint in lumbar>> 45 degress, making it easy to move flexion and extension, but limits lateral felxion.
describe the intervertibral disk structure
Mainly made of WATER
- Account for 25% of the length of the vertebral column
- 70% Water, 20% Collagen, 10% Proteglycans (main role is to bind to water)
- disk Loose height with age why? bc the repair of the proteoglycans is less, so their chains get shprter, and they r less hydrophillic, causing it to loose water from disk, disk will loose height and pressure.
- Slightly wedge-shaped → secondary curvature of spine
Consist of two regions:
– nucleus pulposus (central)
– annulus fibrosus (peripheral)
disk Loose height with age why?
bc the repair of the proteoglycans is less, so their chains get shorter, and they r less hydrophillic, causing it to loose water from disk, disk will loose height and pressure.
the vertebral disk is vascular or Avascular?
they r the largest avascular structures in the body.
they metabolise via DIFFUSION, there is a nutrient artery that enters the vertebrae above and vertebrae below and theres cappillary beds.
what is the nucleus Pulpous?
where is its location?
Functions as a “watercushion” to absorb transient axial loads on the disk.
Remnant of notochord
Gelatinous, made up of Type 2 Collgen and 8–85% water>> since it has alot of GAGS, bc theres such a high water conent in it, It Changes in size throughout day and with age.
Surrounded entirely by annulus fibrosus
the location of the nucleus pulpus in the infant is centrally why? how does this differ in adults.
bc they dont weight bare or walk.
But once we stand and wlak and develop our secondary curves, it is Located more posteriorly in the adults.
Describe the forces that r developed on the spine while we r standing?
Posteriorly>tension forces.
its the tension forces that the ligaments r acting to resist the whole time while gravity is acting on us!
what is the correct way in picking up somthing?
bend ur knees and not ur back!
describe the Curvatures of the vertebral column
In utero we r “kyphotic”>> “primary curvature” the curve we r born with
AS WE GROW and start to move more..
we start to develop 2 lordoisis in cervical and lumbar!
(Lordoses are secondary curvatures )
Explain the Development of the curvature from fetus to young adult
The cervical spine develops the first (cervical lordosis) when young child begins to lift its head
The lumbar spine loses it’s primary kyphosis during crawling
When the child begins to stand- up and walk, lumbar lordosis develops.
(Lumbar lordosis is the second secondary curvature)
Why is the curvutures of our spine important?
bc a centre of gravity acts through our spine
• Passes through vertebral column at:
– C1 & C2
– C7 & T1
– T12 & L1
– L5 & S1
• ‘Weak points’ of vertebral column
How does our vertebral column change in aging?
we tend to lose our secondary curvutures, and we tend to become KYPHOTIC, bc the disks start to lose their height,
- Secondary curvatures start to disappear
- Continuous primary curvature is re-established
- ‘Senile kyphosis’
what do u call this type of curvature?
a physiological curvutre that occurs during pregancy.
Exaggeration of lumbar lordosis during pregnancy
which cervical vertebrae bears the weight of the skull?
Atlas
during a lumbar puncture, how can u identify which level of the lumbar spine ur at?
by PALPATING THE ILAIC CREST>>the top of the iliac crest would equate to L4,5 disk, u can then count the spinous process to identify which level of the spine ur’e at.
THE LOWER THE BETTER.
Describe the different layers u pass when performing Lumbar puncture
What is Mechanical back pain?
Pain in ur back when ur spine is loaded
either with standing or sitting bc gravity is acting on u
when u lie down it should be releived.
triggered by an “unharmful activity”
90% ppl imporove w/ in 3 months.
Describe the dermatomes affected with each effect on the sciatic nerve
ok
Name this muscle
When disk height decreases with age, what consequence can this lead to?
increased stress is also placed on the
facet joints → osteoarthritis
Decreased size of intervertebral
foramen and compression of spinal
(segmental) nerves
what r the unique features of the cervical spine?
(only seenin cervical)
bifid spinous process and Transverse Foramen
what space carries the cerebral vertebral arteries?
Transverse Foramen
what is the 1st cervical vertebra?
what does it articulate w/?
Atlas
with the occipital of the skull
which joint in the cervical region allows 50% rotation and shaking of the head?
what type of joint is it?
how does Axis differ from Atlas?
Atlas has no vertebral body, the body is fused w/ axis to from dens or odontoid process.
-no spinous process
-widest cervical vertebre
who has the longest Spinous process? largest?
Longest>> 7th cervical vertebrae
largest>>Axis!
IF INJURIES OCCUR AT THE LEVEL OF C1, IT IS VERY RARE TO DAMAGE THE SPINAL CORD, WHY?
bc the vertebral foramen is hugee
Axis is charachterized by 3 main features:
– The Odontoid Process or Dens
– Rugged lateral mass
– Large spinous process
what is the odontoid process (or peg)?
in the Axis only!
how does axis articulate with atlas
what prevents the horizontal dispalcment of Atlas
the Dens (odontoid process) of axis joins w/ the articular facet of Atlas
the Dens & transverse ligament!
What is different about C7 w/ the other cervical vertebrae?
it’s vertebral foramen only takes in Vertebral veins (no arteries)
and it has largest spinous process!
Name this & its attatchments
function? (3)
Ligamentum Nuchae
it a thickening of the supraspinous ligament.
Attached to:
– External occipital protruberance
– Spinous processes of all cervical vertebrae
- Maintains secondary curvature of cervical spine
- Helps the cervical spine support the head
- Major site of attachment of neck and trunk muscles (e.g. Trapezius, Rhomboids)
NAME THE LIGAMENTS of the spinal column
which ligament is stronger? the anterior or posterior
Anterior
Label the anterior and posterior cords and explain what each is important for
Anterior Cord
Sensory and Motor
Light Touch, Pinprick and Pain
Posterior Cord (Dorsal Columns)
Vibration and Proprioception
what would happen if someone had a posterior cord syndrome?
Loss of coordination
the more central tracts move the_____
and the more Lateral tracts move the _____
Arms
Legs
explain how the nerve roots exit in the cervical and thoracic vertabral bodies
Nerve Roots in cervical spine exit ABOVE their vertebral body until…. the C7/T1 junction
it starts to run below it!
Label
notice how Axis has a LARGE spinous process
Label the ligaments!
