Intervertebral Discs Flashcards
What kind of joints are intervertebral discs?
Symphyses
Where are ivntervertebral discs located?
Between vertebral bodies from C2 to sacrum
Where are the degenerate discs located?
Between S5 and Cx1
Where are IVDs thicker anteriorly than posteriorly? Why?
- Cervical regions
- Lumbar regions
- Helps created spinal curvatures
Where are IVDs flat?
Thoracic regions
Where are IVDs thinnest?
Upper thoracic
Where are IVDs thickest
Lumbar region
Convex posteriorly
Kyphosis
Convex anteriorly
Lordosis
Lateral curvature
Scoliosis
Discs adhere to inferior surface of a body of a vertebra above and superior surface of the body below via:
Vertebral end plate
Vertebral end plate is a thin layer of:
Hyaline cartilage
Part of the IVD with an outer collagenous zone and a wider, inner fibrocartilage zone
Annulus Fibrosis
Fibers of annulus fibrosis at adjacent laminae arranged obliquely at _____ from horizontal
30 degrees
Oblique arrangement of annulus fibrosis fibers =
Torsional strength to disc
Which direction does the outer lamina bulge of the annulus fibrosis extend?
Externally
Which direction does the inner lamina bulge of the annulus fibrosis extend?
Internally
Function of annulus fibrosis
- Enclose and retain nucleus pulposis
- Absorb compressive shocks
- Structure unit between vertebral bodies
- Allows restricted motion
What percentage of the IVD does the nucleus pulposus make up of?
40%
The nucleus pulposis is a remnant of what embryological structure?
Notochord
When do the notchordal cells disappear?
Within first decade of life
Where are the nucleus pulposuses most developed?
Cervical and lumbar regions
Where are the nucleus pulposus more skewed?
Posteriorly
Nucleus pulposus function
- Resilient spacer allowing motion between vertebrae
- Distributes compressive forces
Nucleus pulposus is extruded through defect in annulus fibrosis
Herniation
Where is a hernia most likely to occur?
Lumbar region, posterolaterally
Where is the annulus fibrosus thinnest?
Posteriorly
Are IVDs vascular or avascular? Exception?
Avascular, except for periphery
What ligaments are IVDs attached to?
Anterior and posterior longitudinal ligaments
What are IVDs attached to the ribs via?
Interarticular ligaments
IVDs contribute to how much of the vertebral column height?
1/5th
Functions of the IVD
- Bearing weight
- Dissipating shock (high water content)
- Distributes loads
- Flexible buffer between rigid vertebrae
- Adequate motion at low loads, stability at higher loads
IVD posterior innervation
Recurrent meningeal nerve
