Symphyses Of Vertebral Column + Thorax Flashcards
IVDs = ~ ___ of height of vertebral column. Where are they thicker and why?
1/5 of height of vertebral column
Lumbar + cervical = ^mobility
What are 5 functions of IVDs?
Bear weight, dissipate shock (^H2O content), distribute load, flexible buffer, adequate motion at low loads, stability at ^loads
IVDs are symphyses found where in the vertebral column? Where are they degenerate discs?
C2 - sacrum
Btwn S5 and Cx1
What helps create spinal curvatures? Where are IVDs flat? Thinnest? Thickest?
Thicker ant. Than post. In cranial + lumbar regions
Flat = thoracic
Thinnest = ^thoracic
Thickest = lumbar
Name + define the curvatures of the spine. What curvature is *pathological?
Kyphosis = convex post.
Lordosis = convex ant.
*Scoliosis = lat. curvature
What can severe, untreated scoliosis cause?
Rib cage deformity + vertebral curvature
How do IVD’s adhere to the bodies of the sup. + inf. Vertebra? Define this structure
Vertebral end plate - thin layer of hyaline cartilage
What is the Annulus Fibrosis composed of? What are the two zones?
Lamellae
Outer collagenous zone
Wider, inner fibrocartilage zone
How are fibers at adjacent laminae of the annulus fibrosis arranged from horizontal? What is the function of this arrangement? How do the 2 zones bulge due to this?
Oblique arrangement (30˚ from horizontal) = torsional strength to disc
Outer lamina - externally; inner - internally
What are the 4 functions of the Annulus fibrosis?
Enclose nucleus pulposus
Absorb compressive shock
Structure btwn vertebral bodies
Allow restricted motion
Nucleus pulposus makes up ___% of bulk of disc. What makes up it’s content? Where is the nucleus pulposus more developed? When is it larger?
40% of disc
^water content, notochord remains
More developed in cervical + lumbar (more post. Than ant.)
Larger at birth, decrease size w/ age
How long do notochordal cells exist in the nucleus pulposus?
Disappear w/in 1st decade of life
What is the function of the nucleus pulposus?
Resilient spacer allows motion btwn vertebrae
Distribute compressive forces
What is herniation of the IVD? What region is herniation most likely to occur, as well as what aspect of the disc? Why?
Nucleus extruded through defect in annulus
Lumbar, posterolaterally - annulus thinnest posteriorly where post. Longitudinal ligament is located.
How does Herniation of IVD become less likely?
With age as nucleus solidifies
