Exam 1 Flashcards
Vertebral body function
resist compressive load
Vertebral pedicle function
Transmit the bending forces from the posterior elements to the vertebral body
Vertebral lamina function
Transmit forces from the articular, transverse and spinous processes to the pedicles
Vertebral transverse procress function
Serve as muscle attachment and provide mechanical lever
Vertebral spinous process function
Serve as muscle attachment and provide mechanical lever; may also serve as bony block to motion
Vertebral foramen function
Combined with all segments, forms a passage and protection for the spinal cord
what does an intervertebral disc consist of?
- nucleus pulposus
- anulus fibrous
- vertebral end plate
what is the nucleus pulpous?
- “Pulp-like gel”
- 70-90% water
- jelly part of intervertebral disc
what is the annulus fibrosis?
- Fibrous outer ring
- 60-70% water
- Collagen and elastin arranged in 15 to 25 concentric layers
- Fibers oriented 65° from vertical
- band portion of intervertebral disc
what is the vertebral end plate
- Cartilaginous layer covering superior and inferior surfaces of the disc
- 0.6 to 1 mm of cartilage in adults, larger in children
- Strongly attached to annulus fibrosis but not the vertebral body
- can be apart of the bone
how much of force is transmitted through intervertebral disc?
80%
what in the intervertebral disc is capable of resisting distraction, shear, and torsion
anulus fibrosis
anterior longitudinal ligament
limits extension
- reinforces anterolateral portion of annulus fibrosis and anterior aspect of intervertebral joints
posterior longitudinal ligament
limits forward flexion
- reinforces posterior portion of anulus fibrosis
ligamentum flavum function
limits forward flexion
- particularly in lumbar area
interspinous ligaments
limits forward flexion
supraspinous ligaments
limits forward flexion
intertransverse ligaments
limits contralateral lateral flexion
what is coupling
consistent association of one motion about an axis with another motion around a different axis
coupling patterns vary based on…
- spinal structure
- spinal curvature
- orientation of articulating facets
- fluidity/elasticity/thickness of the disc
- extensibility of the muscles, ligaments, joint capsules
what do the inter body joints do
- determine magnitude of movement
- distribute load
- create space for movement and passage of spinal nerve roots
what do facet joints do
- determine direction of movement
2. influenced by geometry, height, and spatial disorientation
vertebral flexion is…
anterior tilt and anterior glide of superior vertebra
vertebral flexion results in ..
- widening of intervertebral foramen
- separation of spinous processes
vertebral extension is…
posterior tilt and posterior glide of superior vertebra
vertebral extension results in…
- narrowing of intervertebral foramen
- spinous processes approximate
vertebral lateral flexion is…
lateral tilt, rotation and translation of superior vertebra over inferior vertebra
vertebral lateral flexion results in…
- widening of intervertebral foramen on contralateral side
- narrowing on ipsilateral side
vertebral rotation
- varies by region
- rotation of inter body joint
- approximation/distraction at facet joint
what are the upper cervical vertebra
- occiput
- atlas
- axis
what are the lower cervical vertebra
C3-C7
atypical cervical vertebrae
- atlas
- axis
- C7
what is the function of the atlas
- cradles occiput
2. transmits forces from occiput to C-spine
what is the function of the axis
- transmits combined load of head/atlas to C-spine
2. provides axial rotation of head/atlas
Atlanto-occipital joint
between convex occipital condyles with concave superior facets of atlas
- synovial
antlanto-axial joint
between dens and anterior arch of atlas/transverse ligament
- synovial
AND
between inferior facets of atlas wit superior facts of axis
posterior Atlanto-occpital membrane continues to be..
ligamentum flavum
posterior Atlanto-axial membrane continues to be…
ligmentum flavum
anterior atlanto-occipital membrane continues to be…
anterior longitudinal ligament
tectorial membrane continues to be…
posterior longitudinal ligament
ligamentum nuchae continues to be…
supraspinous ligament
transverse atlanto ligament function
to prevent anterior displacement of C1 on C2
alar ligament function
limit lateral flexion and prevent distraction of C1 on C2
how are the cervical facet joints oriented
45 degrees off frontal and transverse planes
Describe what happens in the upper and lower cervical spine with protraction
upper cervical extension, lower cervical flexion
Describe what happens in the upper and lower cervical spine with retraction.
upper cervical flexion, lower cervical extension
what ligament limits rotation of AA joint
alar ligaments
what ligaments limits tilting of axis at AA joint with flexion
transverse lig
osteology of TMJ
condyle of mandible with articular eminence of temporal bone
classification of inferior TMJ
simple hinge
classification of superior TMJ
functions as a gliding joint
function of lateral TM ligament
stabilize lateral portion of capsule
- help guide movement of condyle during opening