Exam 2 Neuro: Spinal Cord Anatomy Flashcards
What are the 3 spinal meningeal layers & their order inner to outer?
Pia Mater (inner), then Arachnoid layer(middle), & Dura (outer layer)
Collection of nerve roots come from where?
Cauda Equina
What is the end of the spinal cord is called?
Conus Medullaris
What fastens/anchors the base of the spinal cord? At what skeletal landmark?
Filum Terminale & sacral hiatus
What are the two parts of the Filum terminale?
- Filum Terminale internum (Inside the Dural sac)
- Filum Terminale externum
Where does the Dural sac terminate?
S-2
Where does the spinal cord end in an adult?
L-1 to L-2
The Pia mater layer sits right on top of what?
Nervous system tissue (neurons & supporting cells).
Between which 2 layers does CSF flow & what is that space called?
Between Pia & Arachnoid. Called the subarachnoid space.
Where does the Dura layer taper off & why?
At the spinal ganglia. CSF give cushion & nutrition to the neurons
What 2 things are directly located above the dural space?
Fatty tissue & veins
Why are epidurals performed below S-2?
Cauda equina has more space & Dural sac is larger
What wraps around the cauda equina?
The Dural sac
Where are the 2 spinal cord enlargements & why?
- At cervical C3 thru C6 & between T11 thru L1.
- Lots of synapse & cell bodies making decisions for upper & lower extremities
Why does the spinal cord narrow in the thorax?
Not as many sensors. More for signal transport.
Where does the spinal cord end in a newborn?
L-2 to L-3
What is another name for the Dural sac?
Lumbar cistern
What is an incomplete fusion & adjustments should one make?
- Ligmentum flava does not have complete midline fusion.
- Come slightly off midline with epidural.
What is another name for the Pyramidal tracts?
Corticospinal tracts
What is the medulla crossover point for corticospinal tract #1 called & where is it?
Pyramidal Decussation & in the Medulla
What is the primary way for efferent corticospinal tract #1?
Cortex -> Internal capsule -> Pyramids of Medulla -> Pyramidal decussation -> descending the lateral corticospinal tracts -> then lateral tract talks to anterior horns thru, Lamina 8, to motor neuron -> signal exits anterior rootlets
What percentage of pathway does not cross over & travels down which tract?
1-2% & travels down the uncrossed lateral corticospinal tract
Where is the crossover point for the 2nd corticospinal tract?
In the spinal cord at the same level it initiates activity
What is the purpose for Spinocerebellar tracts?
Feedback about movement, coordination