Flashcards in Spinal Cord Anatomy Deck (57)
Describe the following spinal segments:
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?
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?
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- back of head
C6- thumb and index finger
Describe limb rotation of thumbs and big toes.
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.
Describe the dorsolateral fasciculus (zone of Lissauer).
contains finely myelinated and unmyelinated axons originating in the substantia gelatinosa and involved in sensory modulation.
Area where axons ascend or desend several segments (fibers can go up/down cord before leaving or entering...pain)
Describe the anterior commissure.
A spot where fibers cross from one side to another
Describe the gray matter regions.
What is white matter full of?
anterior horn (motor)
posterior horn (sensory)
white matter full of myelin/oligodendrites
Describe all the functional components.
GSA—general somatic afferent—pain, vibration, touch, proprioception from skin, body wall, and skeletal muscle
GVA---general visceral afferent---pain, stretch from guts
GVE---general viscera efferent-----motor to viscera, glands, and blood vessels—autonomics
GSE---general somatic efferent----motor to skeletal muscle
SSA—special sensory afferent----vision, hearing, and balance
SVA—special visceral afferent----taste and smell
SVE---special visceral efferent—innervates muscle of branchiomeric origin—”gills”—pharynx, larynx,mastication, and facial expression—5,7,9,10, and 11
Describe nucleus in regards to the neuroscience definition.
a group of neurons with a common function or modality. Example: hypoglossal nucleus --motor to the tongue (GSE)
(basal ganglia is a nuclei, CN use 1 or more nuclei depending on its functional units)
Describe the alar/basal plates functional components.
alar (dorsal, afferent/sensory) GSA, GVA
basal (ventral, efferent/motor) GVE, GSE
Describe substantia gelatinosa.
What do the cells do?
Where do axons ascend and descend?
What is it homologous to?
What does it receive?
small compact cells that modify sensory input by synapsing on dendrites in nucleus proprius. Axons ascend and descend in Lissauer's tract.
Homologous to spinal trigeminal nucleus
receives mall diameter dorsal root afferents
all cord levels