Spine, IV Disc, and Venous Plexus anatomy Flashcards
How many IV discs are there?
25
Between which vertebrae is there no IV disc?
C1 and C2
What is the action of IV discs?
allow the spine to be flexible without sacrificing a great deal of strength. Provide shock absorbing effect and prevent vertebrae from grinding together
Where is the thickness of the discs the highest?
cervical and lumbar regions
What creates the secondary curvature (lordosis) of the spine?
IV discs in the cervical and lumbar regions are thicker anteriorly
Iv discs consists of 3 major components. List them:
- annulus fibrosus
- nucleus pulposus
- cartilaginous endplates
Annulus Fibrosus
tough circular exterior of the intervertebral disc that surrounds the nucleus pulposus
Nucleus Pulposus
- inner structure
- gelatinous
- high water content
- resists axial forces
Blood supply to the IV discs
- no significant vascular structures
- receive blood supply by diffusion through vertebral body endplates
Cartilaginous endplates
anchor the discs to adjacent vertebrae
At each vertebral level from T4 to the sacrum, a pair of _______ _____ branches posteriorly from the aorta to supply blood to the vertebral body, posterior elements, spinal cord, and costal structures.
segmental arteries
Disc bulges
the circumference of the disc extends beyond the vertebral bodies
Herniation usually occurs
posterolaterally
Herniation of IV disc
puts pressure on the nerve roots or dorsal root ganglion exiting the intervertebral foramen at or below this level, leading to the symptoms of a “slipped disk”
Where do herniations occur most frequently?
cervical and lumbar regions due to them being the most mobile
How many cervical spinal nerves are there?
8 even though there are 7 cervical vertebrae
-starts above C1 and ends below C7 (above T1)
Where is the anterior longitudinal ligament?
extends from the axis (C2) anteriorly to the sacrum
Is the posterior longitudinal ligament stronger or weaker than the anterior longitudinal ligament?
weaker
Where is the posterior longitudinal ligament?
runs from the axis (C2) caudally to the sacrum
The PLL is narrow at the levels of the vertebrae, but the fibers extend _____ at the disc levels. These fibers may help to contain herniated disc material.
laterally
Because the PLL thins laterally, most disc herniations occur in a ______ direction.
posterolateral
The ______ ligament connects each adjacent spinous process.
interspinous
In the cervical spine, the interspinous ligament becomes part of the _____ _____ that extends cranially to insert into the occiput.
ligamentum nuchae
The ___ _____ ligament is a very strong band connecting the tips of contiguous spinous processes. It extends from C7 to the sacrum.
supraspinous ligament
