Vertebral Column and SC Flashcards
How many vertebraes are there?
Vertebral column is composed of 33 vertebrae
- 7 cervical
- 12 thoracic
- 5 lumbar
- Sacrum (5 - fused)
- Coccyx (4 - fused)
Describe 4 key differences in the cervical, thoracic and lumbar vertebraes
(1.) Body
C = Small and oval
T = Heart shaped
L = Kidney shaped
(2.) Vertebral foramen
C = large, triangular
T = small, circular
L = small/medium, triangular
(3.) Transverse foramen
C only, transmits vertebral arteries
(4.) Spinous process
C = Bifid
T = Posterior-inferiorly
L = Posterior
What is the IV disc made up of? and what is its purpose?
(1. ) IV discs are strong fibrocartilage structures that is important for:
- Shock absorber i.e. withstand compression and prevent vertebrae grinding
- Allows for movement between vertebrae
(2. ) Made up of:
- Annulus fibrosis (10-12 layers of collagen)
- Nucleus pulposus (gel structure made up of water, collage, cartilage etc)
(3. ) Discs are thicker in the cervical and lumbar regions
(4. ) No IV disc between C1 and C2
What ligaments surround the vertebral column? And why are they important?
(1. ) Ligaments strengthen and stabilize the vertebral column, and protect the IV discs
(2. ) Anterior and posteriorlongitudinal ligaments = run the full length of the vertebral column
(3. ) Interspinous and supraspinous=join the spinous processes of adjacent vertebrae
(4. ) Ligaments flavum extends between lamina (of spinous process) of adjacent vertebrae.
How many spinal nerve pairs are there?
31 Spinal nerves:
- 8 cervical,
- 12 thoracic,
- 5 lumbar
- 5 sacral
- 1 coccygeal nerve
At what point in the vertebral column does the Spinal cord end?
Spinal cord ends between L1-L2 vertebrae.
Where are Lumbar punctures taken? When are they indicated?
(1.) Lumbar punctures are donebelow the L2 level (usuallybetween L3-4 orL4-5) to avoid injury to thespinal cord.
(2. ) Indications:
- Measure opening pressure in idiopathic intracranial HTN
- MS oligoclonal bands
- Cytology
- CNS infection: meningitis, encephalitis
- SAH
What is the conus medullaris?
- Terminal end of the Spinal Cord
- Spinal cord ends at L1-L2 vertebrae
- Spinal cord is shorter than vertebral column
What is the cauda enquina?
- These are bundle of spinal nerves that extend beyond the conus medularis
- Lumbar and Sacral nerve roots
What is the filum terminale?
- Extends from the conus medullaris to coccyx vertebrae
- Acts as an anchor for spinal cord and meninges
What is a disc herniation? What Sx would be seen?
(1. ) Protrusion of the nucleus pulposus through the anulus fibrosus can put pressure on spinal nerve roots this can cause pain, numbness, weakness.
(2. ) This is usually in the lumbar or cervical regions
(3. ) Pain due to compression of spinal nerve by herniated disc is referred to the area (dermatome) supplied by that nerve.
(4. ) E.g. Sciatica and Cauda Equina Syndrome
what is a radiculopathy?
- Pinched nerve due to compression from a prolapsed IV disc
- Most common are at L5/S1 (Sx in feet) and C6/7 (Sx in forearm)
What is sciatica? Sx?
(1. ) Sciatica nerve becomes pinched, usually due to a herniated disc that compress the L5 or S1.
(2. ) This irritates the sciatica nerve and causes pain along its dermatome
(3. ) Pain in the lower back and radiating to back of thigh and leg.
Where do spinal nerves leave the vertebral column?
(1. ) Nerves exit via the intervertebral foramen
(2. ) IV foramen is a foramen between two spinal vertebrae
(3. ) Gives passage to other structures: vessels, spinal ganglions
Describe the structures of C1/Atlas and it’s points of articulation
- No spinous process
- Transverse ligament separates the vertebral foramen and dens foramen
- Transverse ligament anchors the dens (of C2) in place
Points of articulation
- Atlanto-occipital joint = C1’s superior articular facets + occipital condyles
- Lateral atlanto-axial joint = C1’s inferior articular facets + C2 vertebrae
- Medial atlanto-axial joint = C1’s anterior arch, transverse ligament + C2 dens
