Spinal Cord Anatomy Flashcards
Describe the following spinal segments:
cervical enlargement
lumbar enlargement
cervical enlargement - C5-T1 (why we have brachial plexus)
lumbar enlargement - L1-S2 (why we have lumbo sacral plexus
Describe the relationship between a given vertebral level and the corresponding spinal nerve.
Spinal nerves come out above the same named vertebrae, until nerve c8, which comes out of the cord below vertebra C7. The rest of the nerves come out below their corresponding vertebrae.—Thus vertebra C7 has 2 nerves associated with it—–c7 and c8
How far does the fetal cord extend? What is the significance of this?
to L3
Care must be taken during spinal tap
Describe the meninges.
Dura, Arachnoid, Pia
spinal dura continuous with meningeal layer of cranial dura
dura fuses with epineurium of peripheral nerves
delicate arachnoid trabeculae attach to pia
What is the denticulate ligament?
pial extension anchoring the cord to the dura
Describe motor/sensory, afferent/efferent nerves.
motor tend to be efferent (movement)
sensory tend to be afferent (pain)
Describe sympathetics and splanchnics.
For the most part sympathetics have short preganglionics and long postganglionics—exception: splanchnics, the greater splanchnic (t5-9) synapses in the celiac ganglion, the lesser (t10-11) in the superior mesenteric and aortico renal ganglia, and the least (t12) in the renal plexus.
WIGO. White/grey ramus myelinated?
White “in” grey “out”
grey are unmyelinated
white are myelinated
How does the pia extend?
What does it fuse with and form?
pia extends caudally as filum terminale
fuses with dura to form coccygeal ligament (filum terminale externa)
-attaches to coccyx
Describe the lumbar cistern.
subarachnoid space caudal to conus medullares (L1-S3)
What do cauda equina fibers surround?
sacral cord
Where doe spinal arteries come from?
Describe the spinal cord arteries.
All spinal arteries come from the vertebrals
one anterior, two posterior
anterior spinal artery sits in median anterior fissure. posterior is very tortuous
What do somites give?
dermis, muscle, skeleton
Review the diff between dermatomes and peripheral cutaneous nerves.
?
What are these important/common dermatomal references?
C2,C6
T4,T10
L3, S1
C2- back of head C6- thumb and index finger T4- nipples T-10 umbilicus L3- kneecap S1-lateral foot
Describe limb rotation of thumbs and big toes.
thumbs-laterally
big toes-medially rotate
In regards to the spinal cord/vertebral segment, where does the dorsal root enter?
posterior lateral sulcus (sensory info comes in, dorsal root comes in)
Describe posterior intermediate sulcus
Only above T6
Separation between gracilus and cuneatus
Label the spinal cord/vertebral segment soft chalk.
See powerpoint slide 37.
Describe the anterior median fissure.
Where the anterior spinal artery lives.
Describe the anterior lateral sulcus.
where the ventral root leaves. (motor fibers go out)
Describe the posterior funiculus.
axons forming bundle
White matter ascending axons mostly from the dorsal column pathway.