Vertebrae Flashcards
What is vertebral body osteoporosis
Common metabolic bone disease that is often detected during routine radiograph
Why get osteoporosis
Net demineralization of the bones caused by a disruption of the normal balance of calcium deposition and resorption …quality of bone is reduced and atrophy of skeletal tissue occurs
Most effected areas of osteoporosis
Neck of femur and bodies of vertebrae , metacarpals, and radius
How do you see osteoporosis on a radiograph
Dismissed radiodensity of the trabeculae (spongy)
What is vertical striping and why get it with osteoporosis
Loss of horizontal supporting trabeculae a thickening of vertical struts
Dense stripe seen pillars remain ok longer than rest et stripe
Later stages of osteoporosis what do you see on radiograph
Vertebral column collapse
Compression fractures
Increased thoracic kyphosis n
What vertebrae is oosteoporosis most common in
Thoracic
Laminectomy
Surgical excision of one or more spinous processes and the adjacentt supporting vertebral laminae in a particular region of the vertebral column
Or removing most of the vertebral arch by transectingg the Pedicles
Why do a laminectomy
Gain access to the vertebral canal, providing exposure of the spinal cord and/or the roots of the specific spinal nerves providing posterior exposure of the spinal cords and/or roots of specific spinal nerves
-relieve pressure on the spinal cord or nerve roots caused by a tumor , herniated disc, or bony hypertrophy
Because of their more horizontally oriented articular facets, the __ vertebrae are less tightly interlocked than other vertebrae. What does this cause
Cervical
Dislocation with neck injuries with less force than is required to fracture them
Does dislocation of the cervical vertebrae damage the spinal cord
Due to the large vertebral canal in the cervical region, slight dislocation can occur without damage
But severe dislocations or combined with fractures injure the spinal cord
If the dislocation does not result in facet jumping with locking of the displaced articular processes, the cervical vertebrae may self reduce. Clinically what is issue with this and how correct
Radiograph may not indicate cord has been injured ..USE MRI to see soft tissue damage
What is C1 called . Describe it
Atlas
Bony ring with two wedge shaped lateral masses, connected by thin anterior and posterior arches and a transverse ligament
What kind of forces damage the atlas and why
Vertical forces bc the taller side of the lateral mass is directed laterally …the vertical force compress the lateral masses between the occipital condyles and the axis drive them apart, fracturing one or both of the anterior or posterior arches THIS IS CALLED A JEFFERSON OR BURST FRACTURE
If the vertical force is very strong on the atlas, the __ __ that linkers the arches may also occur
Transverse ligament
Does Jefferson fracture/burst fracture damage the spinal cord
Not necessarily bc the dimensions of the bony ring actually increase
If also rupture the transverse ligament then spinal cord injury more likely
How would a ruptured transverse ligament be seen radiographically
Widely separated lateral masses
What is C2 and what is special about it
Axis
Most commonly fractured cervical vertebrae
Axis fracture
Usually in bony column formed by the superior and inferior articular processes of the axis, the pars inter articular is
What is a fracture of C2 pars interarticularis, called traumatic spondylolysis of C2, caused by
Hyperextension of head on neck
What causes whip lash injury
Hyperextension of head and neck
What is hyperextension of the head called
Hangman’s fracture
What may a severe injury in which the body of C2 vertebra is displaced anteriorly with respect to the body of the C3 vertebrae with or without subluxation of the aaxis cause
Qyadriplegia or death. From injury of spinal cord and or brainstem
What causes Fractures of the dens C2
Also common , caused by horizontal blow to the head or as a complication of osteopenia
Lumbar spinal stenosis
Stenosis vertebral foramen in one or more lumbar vertebrae
Hereditary
More susceptible to IV disc bulging
The lumbar spinal nerves __ in size as the vertebral column descends but the IV foramina ___ in side
Increases
Decreases
In lumbar spinal stenosis, narrowing is maximal where
At level of the IV discs
Can lumbar stenosis cause compression of one or more spinal nerve roots occupying the inferior vertebral canal
Yup
Surgical treatment of lumbar stenosis
Decompressive laminectomy
What happens if there is IV disc protrusion in a patient with spinal stenosis
Further compromises a vertebral canal that is already limited , as does arthritic proliferation and ligamentous degeneration
Cervical ribs
Common 1-2% of people hav C7 costal element which becomes a small part of the transverse process that lies anterior to the foramen transversarium becomes enlarged
Vary size and is bilateral 60%
What does supernumerary extra rib cause
Elevate and place pressure on structures that emerge from he superior thoracic aperture , notable the subclavian artery or inferior trunk of the brachial plexus and may cause thoracic outlet syndrome
In living people, the sacral hiatus is closed bu the membranous __ __, which is pierced by what
Sacrococcygeal ligament
Film terminate (a connective tissue strand extending front he tip of the spinal cord to the coccyx)
Deep (superior ) to the ligament , the epidural space of the sacral canal is filled with fatty connective tissue.
Ya
In caudal epidural anesthesia where is Anastasia injected
Into fat around the sacral canal that surrounds the proximal portions of the sacral nerves
Route: through sacral hiatus
How can you locate the sacral hiatus
Palpate. It is between the sacral cornea and inferior to the s4 spinous process or median sacral crest
Once through the sacral hiatus and injection into the fat, how does anesthesia spread and work
Spreads superiorly and extradurally where it acts on ss2-co1 spinal nerves of causal equine
How do you control the height to which anesthesia spreads
Amount that you put in and position of patient
How else can anesthetic be injected into sacral canal around spinal nerves and what is this called
Through posterior sacral foramina into sacral canal
Transsacral epidural anesthesia
What may an abrupt fall on buttocks cause
Subperiosteal bruising or fracture of the coccyx or a fracture-dislocation of the sacrococcygeal joint
Can coccyx be damaged in child birth
Ya
Coccygodynia (coccydynia)
Syndrome that often follows coccygeal trauma
Pain in coccyx of tail bone area
Pain management can be hard
In 5% of people, __ is partially or completely incorporated into the sacrum. What is this called
L5
Hemisacralization (partially) or sacrilization (completely)of the L5 vertebra
What is lumbrilization fo S1 vertebra
S1 is separated from the sacrum. And is partly or completely fused with L5
What clinical problem with L5-S1 lumbrarization
L5-S1 is strong
L4-L5 weak and degenerates, often causing PAIN
Between birth and 5 the lumbar vertebra increase in height ____, and between 5 and 12, it increases another ___%
3 fold
45-50%
When is longitudinal growth finished
18-25
What happens middle age and older
Decrease in bone density and strength, particularly centrally in vertebrae body
The articular surfaces graduallly bow inward so that both the superior and inferior surfaces of the vertebrae become increasingly concave and IV discs become convex
Clinical issue with concavities
Narrowing or intervertebral space
NOT a loss of IV disc thickness
What does aging of IV discs and changing shape of vertebrae cause
Increase in compressive forces at the periphery of the vertebral bodies, where discs are attached.
Causes osteophytes(bone spurs) to develop around the margins of the vertebral body esp anteriorly and posteriorly
What happens as altered mechanics place greater stresses on the zygapophysial joint
Esteophytes develop along the attachments of the joint capsules and accessory ligaments esp superior articular process, whereas exetensions of the articular cartilage develop around the articular facets of the inferior processes
These bony or cartilaginous growth during advanced age have been viewed as a disease process, ____ in the case of vertebral bodies and ____ in case of zygapophysial joints, but can consider it normal anatomy of people of an age(maybe shouldn’t be pathological bc relating to pain is hard)
Spondylosis
Osteoarthrosis
Sometimes the epiphysis of a transverse process fails to fuse. Why is this a problem
Don’t mistake it for vertebral fracture in a radiograph or ct
Spina bifida occulta
Neural arches of L5 and/or S1 fail to develop normally and fuse posterior to the vertebral canal
24% of pop usually in vertebral arch of L5 and/or S1
Small dimple or tuft of hair from lower back
Back problems
Palpate baby to see if vertebral arches are intact and continuous from the cervical to the sacral regions
Spina bifida cystica
One or more vertebral arches may fail to develop completely
Herniation of meninges
Meningocele
Spina bifida associated with meningeal cyst
Meningomyelocele
Spinal cord protrudes
Neurological symptoms present-paralysis of the limbs and distribances in bladder and bowel control
Severe forms of spina bifida result from the ___ ___ ___
Neural tube defects
Such as the defective closure of the neural tube during the 4th week of embryonic development
With advancing age, what happens to nucleus pulposi
Dehydrate and lose elastin and proteoglygans while gaining collagen
IV discs lose Turcot, becoming stuff and more resistant to deformation
How does this effect the nucleus pulposi
Dehydrate and the two parts of the disc appear to merge as the distinction between them becomes increasingly diminished
Becomes dry and granular and may disappear altogether
As the nucleus pulposi disappears, the ___ ___ assumes an increasingly greater share of the vertical load and the stresses and strains that come with it
Annulus fibrosis
What happens as the lamellar of the annulus thicken
Develop fissures and cavities
What is the most common reason for slight loss of height as age
the margins of adjacent vertebral bodies may approach more closely as the superior and inferior surfaces of the body become shallow concavities
*note the IV discs increase in size
Not only do the intervertebral discs become more convex but between 20 and 70, their __ diameters increases 10% in females and 2% in males .
AP
The thickness (height) increases centrally about 10% over both sexes. What if it is more
Overt narrowing, especially when it is greater than that of more superiorly located discs, suggests pathology (degenerative disc disease), not normal aging
Top two reasons people visit doctor
Cold
Back pain
Two biggest causes of lost work days
Headache
Backache
What 5 categories of structures receive innervation in the back and can be sources of pain
Fibroskeleton(periosteum, ligaments, annulus fibrosi of IV disc)
Meninges
Synovial joints (capsule of zygapophysial joints)
Muscles
Nervous tissue : spinal nerves or nerve roots exiting the IV foramina
What innervates the fibroskeleton and meninges
Recurrent meningeal branches of the spinal nerves
What innervates the synovial joints and intrinsic back muscles
Posterior rami (articular and muscular branches)
Pain from nervous tissue-caused by compression or irritation of spinal nerves or nerve roots-is called ___ ___, perceived as coming from the cutaneous or subcutaneous area supplied by that nerve (dermatomes
Referred pain
*can be accompanied by localized pain
Localized lower back pain
Perceived as coming from the back is generally muscular, joint, or fibroskeletal pain.
Muscular-usually related to reflexive cramping (spasm) producing ischemia, often secondarily as a result of guarding
Zygapophysial-associated with aging (osteoarthritis) or disease (RA)
Pain from vertebral fractures-sharp pain mostly periosteal
Dislocations-ligamentous
IV disc herniation-emanates from the disrupted posterolateral anulus fibrosis and impingement on the posterior longitudinal ligament
Pain in all these latter instances is conveyed initially by the meningeal branches of the spinal nerves
Clinical presentation of herniated nucleus pulposus
Lower back pain and lower limb pain
Also can be asymptomatic
IV discs are strong in young people with a high water content . Do they get fractures or rupture first
Fracture before discs rupture
More water more Turgor
What may rupture an IV disc and fracture
Violent hyperextension
What does flexion of vertebral column cause
Compression anteriorly and stretching/tension posteriorly
Squeezing nucleus pulposus further posteriorly toward thinnest part of anulus fibrosis (if degenerated may herneate into vertebral canal and compress spinal cord or nerve roots of cauda equina)
Herniation of L4 L5 disc
Sparing L4 spinal nerve but compressing L5 and other nerves passing to lower levels
What is the cauda equina
Bundle of spinal nerve and spinal nerve rootlets consisting of the second through fifth lumbar nerve pairs , the 1-5 sacral nerve pairs, and the coccygeal nerve all of which arise from the lumbar enlargement and the conus medularis of the spinal cord
Where does nucleus pulposus usually herniate
Posterolaterally where anulus fibrosis is thin and does not get support from posterior or anterior longitudinal ligaments
Why is a posterior lateral herniation usually symptomatic
Proximity of the spinal nerve roots
Is the nucleus pulposus sensitive
No
Localized back Pain of PL herniated disc
Acute pain from pressure on longitudinal ligaments and periphery of the anulus fibrosus and from local inflammation caused by chemical irritation by substances from ruptured nucleus pulposus
Chronic pain from compression of the spinal nerve roots by hernaited disc
Referred radiating pain
Perceived as coming from he dermatome supplied by that nerve
Where are PL herniation of the nucleus pulposus most common and why
Lumbar and lumbosacral regions where movements are consequently greater and IV discs are largest
Where are 95% of lumbar disc protrusions
L4-L5, L5-S1
With disc herniation what foes the decrease in intervertebral space (disc height) cause
Narrowing of the of the IV foramina exacerbating compression of the spinal nerve roots, especially if hypertrophy of the surrounding bone has also occurred
Since nucleus gets more dehydrates and fibrous/granular with age, is acute herniation common in advanced years? What would you suspect over it
No
Suspect nerve roots being compressed by increased ossification of the IV foramen as they exit
Acute pain in lower back
Suspect mild PL protrusion of lumbar IV disc at L5-S1 such as those assocatied with the posterior longitudinal ligament
Muscle spasm associated with low back pain
Lumbar region of vertebral column becomes tense and cramped as relative ischemia occurs, causing painful movements
Sciatica
Radiates from lower back into the buttock and down posterior or lateral aspect of the thigh into the leg
Common cause of sciatica
Herniated lumbar IV disc that compromises L5 or S1 component of the sciatic nerve
What movement may produce or exacerbate sciatic pain
Flex thigh with knee extended
Can osteophytes cause sciatica
Ya
What other movements may also damage IV discs
Violent rotation or flexing
When an IV disc protrudes, it usually compresses the nerve root numbered one __ to the herniated disc. L5 nerve root is compressed by what herniation
Inferior
L4-L5
The spinal nerve roots descend to the IV foramen from which the spinal nerve ____ by their merging will exit
Formed
The nerve that exits a given IV foramen passes through the ___ bony half of the foramen and this lies ___ and is not affected by a herniated disc at that level
Superior
Above
The nerve roots passing to the IV foramen immediately and farther below pass directly across the area of herniation
Symptom producing IV disc protrusions occur in the cervical region almost as often as in the lumbar region
What may chronic or sudden forcible hyperflexion of the cervical region (head on collision or during illegal head blocking in football) cause. Why does that happen in this region
Rupture IV disc posteriorly without fracturing the vertebral body
In this region the IV discs are centrally placed int he anterior border of the IV foramen and a herniated disc compresses the nerve actually exiting at the level of the disc (rather than below as in the lumbar region)
Soooo if you herniate a cervical disc is the above or below nerve affected
Below
C5-6, C6
C6-7, C7
Where do cervical disc ruptures cause pain
Neck, shoulder, arm, hand
Degenerative disc disease that results in a markedly diminished IV disc space causes __ ___ that may be treated with laminectomy with or without spinal fusion
Spinal stenosis
What do laminectomy and spinal fusion do
Laminectomy-decompress involved nerves
Spinal fusion (athrodesis)-eliminates movement between two or more segments of the back that may produce additional compression by using bone to make a bridge between adjacent vertebrae which will be replaced by new bone that unites the adjacent vertebral bodies (rod until bone formed)
What does spinal fusion treat
Numbness, pain, or weakness in lower limbs rather than back pain
Increase range of motion
Artificial disc replacement
Alternative to fusion when one or two segments are involved
Restores disc space lost due to disc degeneration , relieving stenosis while allowing motion to occur
Also prevents premature breakdown of adjacent segments
Why are zygapophysial joints of clinical interest
Close to IV foramina through which the spinal nerves emerge from the vertebral canal
What is often affected when the zygapophysial joints develop osteophytes(osteoarthritis)
Spinal nerves are often affected , causing pain along the distribution patterns of the dermatomes and spasm in the muscles derived from the associated myotomes
What is enervation of lumbar zygapophysial joints
Procedure for treatment of back pain caused by disease of these joints. Nerves are sectioned near the joints or are destroyed by radiofrequency percutaneous rhizolysis. The dinner action is directed at the articular branches of two adjacent posterior rami of the spinal nerves because each joint receives innervation from both the nerve exiting at that level and the superjacent nerve
Sudden forceful flexion (automobile accident or violent blow to the head)
Crush or compression fracture of the body of one or more vertebrae
Violent anterior movement of vertebrae with compression
Vertebra may be displaced anteriorly on the vertebra inferior to it (dislocate C6 or C7 vertebrae)
Usually displacement dislocates and fractures the articular facets between the two vertebrae and ruptures the interspinous ligaments
Sudden forceful extension (head butting. Or illegal face blocking in football )
Injure posterior parts of the vertebrae , fracturing by crush or compression of the vertebral arches and Their processes
Why do fractures of cervical vertebrae radiate pain to back of neck and scapular region
Same spinal sensory ganglia and spinal cord segments receive pain impulses from he vertebrae are also involved in supplying neck muscles
Severe hyperextension of neck (whip lash) from rear end motor collision injuries esp with head rest low
Anterior longitudinal ligament is is stretched and may be torn
Hyperflexion injury of the vertebrae may also occur as the head rebounds after the hyperextension snapping the head forward on the thorax. What does this cause
Facet jumping, or locking of the cervical vertebrae may occur because of dislocation of the vertebral arches.
Severe hyperextension may also produce hang mans fracture , rupture of anterior longitudinal ligament and adjacent anulus fibrosis of C2-C3 IV
If this injury occurs the cranium, C1 and the anterior portion (dens and body) or C2 are separated from the rest of the axial skeleton ….what happens
Spinal cord is usually severed and person doesn’t survive really
What causes most fractures of the cervical region
Football, diving, falls (from horse), and MVC
Is the lumbar region less flexible than thoracic
No more
What are the most commonly fractures thoracic vertebrae and why
T11 and 12 bc of the abrupt change to the lumbar region which has more flexibility
They participate in rotary movements superiorly but only flexion and extension movements inferiorly
Why is dislocation of vertebrae uncommon in thoracic and lumbar regions
Interlocking of their articular processes
What fracture breaks the interlocking mechanism
Soondylolysis-fracture of the column of bones connecting the superior and inferior articular processes (pars interarticularis or interarticular part)
Subsequently, what may happen after spondylolysis
Spondylolisthesis
Fracture of interarticular parts of the vertebral laminae of L5(spondylolysis of L5) may results in spondylolisthesis of L5 vertebral body relative to the sacrum due to downward tilt of L5/S1 IV joint
Spondylolisthesis at L5S1 IV joint may result in pressure on the spinal nerves of the __ ___ as they pass into the superior part of the sacrum causing lower back and limb pain
Cauda equina
Which is stronger: the transverse ligament of the atlas or the dens of C2 vertebra
Transverse ligament
*note fractures of the dens make up 40% of fractures of the axis
Where does the most common dens fracture occur
Base
Why are base fractures of the dens unstable(don’t reunite)
The transverse ligament of the atlas becomes interposed between fragments and bc the separated fragments no longer have a blood supply which results in AVASCULAR NECROSIS
Fractures of the vertebral body inferior to the base of the dens
Also common
Heals more readily bc fragments retain their blood supply
What happens when transverse ligament of the atlas sutures
The dens of the axis is set free resulting in atlantoaxial subluxation -incomplete dislocation of the median Atlanta-axial joint
What causes pathological softening of the transverse and adjacent ligaments
Connective tissue disorders
May also cause atlantoaxial subluxation
Down’s syndrome
Is dislocation owing to transverse ligament rupture or a genesis more likely to cause spinal cord compression than that resulting from fracture of the dens
Yup
The dens fragment is held in place against the anterior arch of the atlas by the transverse ligament and the dens and atlas move as a unit
In the absence of a competent ligament the upper cervical region of the spinal cord may be compressed between the approximated posterior arch of the atlas and the dens, causing what
Paralysis of all four limbs (quadroplegia) or into the medulla of the brainstem resulting in death
What is Steele’s rule of thirds
1/3 of atlas ring is occupied by the dens, one third the spinal cord, and 1/3 fluid filled space and tissues surrounding the cord
Why may some people with anterior displacement of the atlas be asymptomatic
Rule of thirds ]
Sometimes inflammation in the craniovertebral area may produce softening of the ligaments of the craniovertebral joints and cause dislocation of the atlanto-axial joints
Sudden movement of a patient from a bed to a chair may produce posterior displacement of the dens of the axis and injury to spinal cord
Are the alar ligaments stronger than the transverse ligaments
No weaker
What movement tears one or both alar ligaments
Combined flexion and rotation or head
What does rupture of alar ligaments cause
Increase of approximately 30% in the range of movement to the contralateral side
Dowager hump
Excessive thoracic kyphosis in older women resulting from osteoporosis but also in elderly men
What does osteoporosis effect most
Horizontal trabeculae or trabecular bone of the vertebral body
The remaining unsupported vertical trabeculae are less able to resist compression and sustain compression fractures, resulting in short and wedge shaped thoracic vertebrae
The excessive kyphosis leads to an increase n the AP diameter of the thorax and a significant reduction in what
Dynamic pulmonary capacity
What is excessive lumbar lordosis associated with
Weakened trunk musculature, especially anterolateral abdominal muscles
*pregnancy (low back pain that disappears after birth)
Obesity
Scoliosis
Curvature accompanied by rotation spinous processes turn upward toward the cavity of the abnormal curvature and when the individual bends over, the ribs rotate posteriorly(protrude) on the side of the increased convexity
Hemivertebrae
Failure of half of the vertebrae to develop
Cause structural scoliosis
Combination of structural scoliosis with excessive thoracic kyphosis
Kyphoscoliosis
Abnormal AP diameter produces severe restriction of the thorax and lung expansion
Idiopathic scoliosis in girls and boys
Girls 10-14
Boys 12-15
Myopathy scoliosis
Asymmetric weakness of intrinsic back muscles
Functional scoliosis
Different int he length of the lower limbs with a compensatory pelvic tilt
When scoliosis is entirely postural it disappears during maximal __
Flexion
Why do you need to warm up and stretch before work out
Increase tonus of the core muscles to prevent strain and sprains which are common causes of lower back pain
Back sprain
Only ligamentous tissue or the attachment of ligament to bone is involved without dislocation or fracture
Results from strong contractions related to movements of the vertebral column such as excessive extension or rotation
Back strain
Sports
From overly strong muscular contraction
Some degree of stretching or microscopic tearing of muscle fibers
-lumbar joint muscles, erector spinae
Using back as a lever when lighting weights
Strain on the vertebral column and its ligaments and muscles
Strains minimized if I’ve butt and lower limbs by keeping back straight
What is protective mechanism of back muscles after injury or response to inflammation
A spasm
Cause cramps and pain , involuntary movements
When is the winding course of the vertebral arteries through the foramina transversarii of the transverse processes of the cervical vertebrae and theought the suboccipital triangles clinically significant
Blood flow through these arteries is reduced, as occurs with ATHEROSCLEROSIS
-under these conditions prolonged head turning (backing up car) cause light headed ness, dizziness, and other symptoms s from decreased blood supply to the brainstem
The lumbar spinal nerves ___ in size from superior to inferior
Increase
The IV foramina ___ in diameter from superior to inferior
Decrease
The __ spinal nerve roots are the thickest with the narrowest foramina. This increase chance of what
L5
Compression if osteophytes develop or herniation of IV disc
Myelography
Radioopaque contrast procedure that allows visualization of the spinal cord and spinal nerve roots
How perform a myelography
CSF drawn by lumbar puncture and replaced with a contrast media injected into subarachnoid space
-this shows extent of subarachnoid space and its extensions around the spinalnerve roots within the dural root sheaths
-use high resolution MRI instead
Together the arachnoid and pia mater form the ____
Leptomeninges
How do leptomeninges develop
As a single layer from the mesenchyme surrounding the embryonic spinal cord
Subarachnoid space
Fluid filled spaces form between pia and arachnoid
Oder of layers
Brain and spine -dura, arachnoid, pia on inside
Lumbar puncture
Withdrawal of CSF from lumbar cistern for evaluating CNS disorders
Body position while perform lumbar puncture
On side with knees to chest
Flexion facilitates insertion of the needle by spreading apart the vertebral laminae and spinous processes, stretching the ligaments flava
Where do lumbar puncture
L3 and L4 is L4 L5 between the spinous processes
What spinal level at iliac crest
L4 spinous process
Path of needle
Punctures ligamentum Flava, then dura and arachnoid and enters lumbar cistern
When do we not perform a lumbar puncture and how can we telll this
Increased intracranial pressure
CT or fundus of interior eyeball (papilledema)
Spinal anesthesia
Anesthesia injected into subarachnoid space..anesthesia within 1 min
Headache may follow from CSF leak
Epidural anesthesia (block)
Injected into the epidural space using the position described for lumbar puncture or sacral hiatus
The segmental reinforcements of the blood supply to the spinal cord front the ___ ___ arteries are important in supplying blood to the anterior and posterior spinal arteries
Segmental medullary
Fractures, dislocations, and fracture-dislocations may interefere with blood supply to the spinal cord. Why
From spinal and medullary arteries
What happens if have deficient blood supply (ischemia) of the spinal cord
Affect function and can lead to muscle weakness and paralysis
Also circulatory impairment if the segmental medullary arteries (great anterior segmental medullary artery of Adam kite wick) are narrowed by obstructive arterial disease
Sometimes the aorta is purposely occluded (cross clamped) during surgery . Patients undergoing such surgeries and those with ruptured aneurysms of the aorta or occlusion of the great anterior segmental medullary artery may have what symptoms
Lose all sensation and voluntary movement inferior to the level of impaired blood supply to the spinal cord (paraplegia)secondary to death of neurons in the part of the spinal cord supplied by the anterior spinal artery
Why will neurons with cell bodies distant from the site of ischemia of the spinal cord also die
Secondary to the degeneration of axons traversing the site
Iatrogenic paraplegia
Aorta clamp in surgery
When. Systemic blood pressure drops for 3-6 minutes, blood flow from the segmental medullary arteries in the anterior spinal artery supplying the midthoracic region of the spinal cord may be reduced or stopped. What may they experience
Lose sensation and voluntary movement in the areas supplied by the affected level of the spinal cord
Describe cervical vertebral canal
Narrow, like lumbar.
Narrow cervical vertebral canal dangerous?
Of course. Minor fracture and or dislocation of cervical vertebra may damage spinal cord
Spinal cord shock
Protrusion of cervical IV disc into the vertebral canal after a neck injury associated with transient depression or abolition of reflex activity or paralysis inferior to the site of lesion
During autopsy what signs indicate protrusion of IV disc in spinal shock
Swollen ligamenta flava, osteoarthritis of zygapophysial joint may exert pressure on cauda equina
Lumbar spondylosis
Degenerative joint disease.
Osteoarthritis of ZP joint exert pressure on cauda equina
Pain and stiffness
Transaction of the spinal cord results in loss of all sensation and voluntary movement inferior to the lesion
Yup
Transaction C1-C3
No function below the head level: a ventilator is required to maintain respiration
Transcetion c4-c5
Quadriplegia (no function of upper and lower limbs) respiration occurs
Transaction C6-8
Low of lower limb function combined with a loss of hand and a variable amount of upper limb function; the individual may be able to self feed or propel a wheelchair
Transcetion T1-T9
Paraplegia (paralysis of both lower legs) amount of trunk movement depends on height of lesion
Transcetion T10-L1
Some thigh muscle function while may allow walking with long leg braces
Transcetion L2-L3
Retention of most leg muscle function; short leg braces may be required for walking
