Spine and Spinal Cord Flashcards
What spinal cord end forms the posterior coccygeal ligament?
Filum terminale
At what vertebral level does the spinal cord lay at each of the following ages?
3 months gestation
Birth
Adult
3 months gestation: end of spinal canal
Birth: L3
Adults: L1-L2
Where does the C1 root exit?
Is there a dorsal root to C1?
C1 root exits between occiput and atlas
There is no dorsal root to C1
Within the posterior nerve roots, where within the nerve root are pain/temperature sensation and proprioceptive fibers located?
Pain/temperature fibers are lateral
Proprioceptive fibers are medial
How many posterolateral sulci are there and what lies near them?
What does the posterior intermediate sulcus separate?
2 posterolateral sulci and are near DREZs
Posterior intermediate sulcus separates fasiculus cuneatus from gracilus
Which rexed laminae caps the posterior horn?
What inputs does it receive?
What type of sensation does it receive?
What neurotransmitters?
Rexed laminae I
DRG and from II
Pain/temperature
Substance P, Enkephalin, 5HT, Somatostatin
Which rexed laminae is also known as the substantia gelatinosa?
Where does it receive inputs from?
What is the major neurotransmitter?
II
Posterior columns, dorsolateral, and lateral funiculi with slow pain (C fibers)
Substance P
Which two rexed layers have a high density of opiate and substance P receptors?
Laminae I and II
C0-C2 ligaments
long tracts of SC
Dorsal column-medial lemniscus (DCML)
**First-order neuron
**Peripheral sensation X
Dorsal root X
Dorsal horn of the spinal cord X
Fasciculus gracilis or cuneatus (dorsal column) X
**Second-order neuron
**Nucleus gracilis (NG) or cuneatus (NC) X
Medial lemniscus after NG and NC X
**Third-order neuron
**Ventralposterolateral thalamus X
Thalamocortical tract X
Somatosensory cortex
Lissauer tract
Somatosensory information arising from the skin enters into the spinal cord via the dorsal horn. From here, it can ascend into the thalamus. Some of those fibers ascend or descend locally, across one or two spinal segments. The white matter bundles that only project within the spinal cord are called Lissauer’s tract, or the posterolateral tract. These axons mostly carry crude touch and pressure information.
rexed lamina functions
rexed lamina
The dorsal and ventral horns of the spinal cord contain 10 different layers of grey matter, known as the Rexed laminae. Just as the Brodmann areas map the cortex according to the cytoarchitecture (cellular structure) of each of its parts, the Rexed laminae distinguish 10 different layers in the spinal cord on the basis of the characteristics of their neurons.
The dorsal horn, where the first connections in the pain pathways are made, contains laminae I to VI, while the ventral horn, comprising the motor neurons, contains laminae VII to IX. Lamina X surrounds the central canal.
Numerous studies of the physiology of the spinal cord have confirmed that this division based on cell types has functional bases as well.
Spinal dysraphism classification
**1.open spinal dysraphism
**
myelomeningocele (98% of open spinal dysraphism)
myelocele
myeloschisis
hemimyelomeningocele
hemimyelocele
**2. closed spinal dysraphism
**
**2/A with subcutaneous mass
**
lipoma with dural defect
lipomyelomeningocele
lipomyelocele/lipomyeloschisis
terminal myelocystocele
meningocele
limited dorsal myeloschisis
**2/B without subcutaneous mass
**
posterior spina bifida (isolated defect of the posterior neural arch of vertebra)
intradural lipoma
filar lipoma
tight filum terminale
persistent terminal ventricle
disorders of midline notochordal integration:
dorsal dermal sinus, dorsal enteric fistula, neurenteric cyst, split cord malformations, diastematomyelia, diplomyelia,
disorders of notochordal formation: caudal regression syndrome, segmental spinal dysgenesis
Perineural cyst
Tarlov cyst
Tarlov cysts, also called perineural cysts, are CSF-filled dilatations of the nerve root sheath at the dorsal root ganglion (posterior nerve root sheath). These are type II spinal meningeal cysts that are, by definition, extradural but contain neural tissue.
Most Tarlov cysts are asymptomatic, but in some individuals can lead to neurological dysfunction and pain. These have been termed sacral symptomatic Tarlov cysts
spinal stenosis pathology
sup process of joint, lig. flavum, disc, tarlov cyst, epidural lipid
Wallenberg
