Cervical Spine Anatomy, Neurology & Biomechanics Flashcards
Which part of the vertebral body in the CS is an origin for cervical muscles?
-transverse processes
How does the cervical vertebral body compare with the lumbar vertebral body?
-cervical vertebral body is thinner & wider compared to TS & LS
Name of the opening in which the spinal nerve passes through in CS.
-foraminal gutter (sulcus or groove)
Where is the foraminal gutter specifically located between each vertebral body
-between the anterior & posterior tubercles of the transverse process
transverse foramen holds what structure?
-vertebral artery
Differences of LS disc & CS disc
CS disc:
- lamellae do not exhibit alternating orientations. posterior part of disc consists of vertically oriented fibers.
- structure of a dense anterior interosseous ligament with few fibers to contain the NP
- posterolaterally the NP is contained by the alar fibers of the PLL & UVJ
- vertical height of disc is 2 times greater anteriorly than posteriorly
- thinner than LS disc
At what age is there a decrease in the blood supply resulting in overall loss of disc height?
-20 yrs old
fissures in CS disc
-result of normal mechanics & usually are not painful
How are the inferior facets in the CS oriented?
-anteriorly & downward
How are the superior facets oriented in the CS?
-posteriorly & upward
CS facet joint is what type of joint?
-synovial joint with hyaline cartilage
Strengths & weaknesses of CS facet joint capsule?
- strong anteriorly
- thin & weak posteriorly
How does the CS facet joint allow for translation?
-the joint becomes lax in neutral & extension
CS facet joint meniscoids
-vascular, fat-filled, intra-articular inclusions that consist of connective tissue & are innervated
CS facet joint meniscoids function
-space fillers
What are the CS facet joint meniscoids prone to?
-entrapment
What happens to the CS facet joints with age?
-atrophy & disappear
CS facet joint orientation
-45 degree angle to horizontal
What motion does the CS facet joint facilitate?
-rotation
CS facet joint capsular pattern
-extension > SB, rot; flexion not affected
In what position do the disc & facet joints in the CS bear equal vertical compressive forces?
-erect standing position
Function of uncovertebral joints
- contain the posterolateral border of the IVD
- guide CS flexion & extension
- reduce SB of CS
- prevent posterior translation of neighboring vertebra
Why is it thought that the uncovertebral joints wear out faster (5-7x) more than other joints?
-most likely due to additional loading on these joints associated with increased disc fissuring & loss of disc height & shear forces on the joint during vertical movement [usually not painful but will see crepitus & decreased ROM]
innervation of ALL & PLL
-sinuvertebral nerve (anterior rami of C1-C6
CS deep layer muscles
- rectus capitus posterior minor
- rectus capitus posterior major
- oblique capitus inferior
- oblique capitus superior
- transversospinalis
CS intermediate layer muscles
- semispinalis capitus
- semispinalis cervicis
- intertransersarii
- scalenes
- splenius capitus
- splenius cervicis
- levator scapulae
CS superficial layer muscles
- SCM
2. upper trap
CS anterior muscles
- rectus capitus lateralis
- rectus capitus anterior minor
- rectus capitus anterior major
- longus cervicis/longus coli
Locations of where CS nerve roots exit the vertebrae
-8 cervical nerve roots each exiting above the vertebra which it is named for EXCEPT C8 which exits below C7
Anterior nerve compression at CS is caused by which structures?
-likely caused by protruding discs & osteophytes of the uncovertebral region
Posterior nerve compression at CS is caused by structures?
-likely caused by superior articular process, the ligamentum flavum
CS disc innervation
-sinuvertebral nerve (anterior rami C1-C6)
CS facet joint innervation
-dorsal cervical rami from C2-C8 and the sinuvertebral nerve
normal CS flexion range
0-(45-60) degrees
How do the vertebra & disc move during CS flexion?
- superior vertebra tilts anteriorly & glides superiorly over the vertebra below
- ventral compression & dorsal distraction of disc
Limiters of CS flexion?
- SS, IS, & PLL ligaments
- ligamentum flavum
- ligamentum nuchae
- capsular ligaments
- facet orientation
- cervical extensor muscles
normal CS extension range
0-(60-80) degrees
How do the vertebra & disc move during CS extension?
- superior vertebra tilts posteriorly & glides inferiorly over the vertebra below
- IVF narrows & spinous processes approximate
Does flexion or extension place the CS in the closed packed position?
-CS extension
Limiters of CS extension?
- disc size
- bony contact of spinous processes or facet & transverse processes
- tension in facet joints
- anterior annulus
- anterior trunk muscles
- ALL
normal CS rotation range
0-(50-70) degrees
Where is the fulcrum located during CS rotation?
-initial fulcrum is the disc until the facets close on side rotating toward & then those facets become the fulcrum
Movement of facets during CS rotation?
- facets glide inferiorly on the side rotating toward & superior on the opposite side
- side rotating towards closes down & opposite side opens up
normal CS side bending range
0-(25-50) degrees
How do the CS structures move during CS side bending?
- superior vertebra tilts to the side you are side bending towards & glides inferiorly over vertebra below
- facet on opposite side glides superiorly
- annulus is compressed on concavity of curve & stretched on convexity
- side bending towards closes down & opposite side opens up
Limiters of CS side bending
- facets on the same side
- passive tension in annulus
- intertransverse ligaments & posterior trunk muscles
Coupled movements in CS
-generally SB & rotation are coupled IPSILATERAL but in extreme flexion, SB & rotation go opposite one another
combined movement in CS
-SB & rotation contralateral
Which segments in the CS have fairly equal SB/rotation?
C2-C4
Does lower or upper CS have more rotation and why?
-lower CS due to plane of facets
Which CS segments has the greatest mobility?
-C5-C6 usually has greatest mobility, least amount of resistance with movement
