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Med Neuro Lect7
Med Neuro Lect7 Spinal Cord and Peripheral Nerves
Question | Answer |
---|---|
What key foramen is located/created above/by the pedicles? | Intervertebral Foramina |
How is the epidural space in the spinal column different from that in the skull? | It contains Fat and a Venous Plexus!! |
What are the Processes associated with the vertebral Lamina? | 1.Superior Articular Process. 2.Inferior Articular Process. 3.Transverse Process. 4.Spinous Process. |
Zygapophyseal Joint | formed b/w the sup & inf articular processes. **also called facets. |
3 Longitudinal Ligaments in the spinal column and their main actions/resistance | 1.Ligamentum Flavum (considered longitudinal even though it is interrupted by lamina): provides resistance during FLEXION. 2.Posterior Longitudinal Ligament (not musch resistance). 3.Anterior Longitudinal Ligament: provides resistance during EXTENSION. |
Does the Ligamentum Flavum buckle during extension since it is stretched so much during flexion? | NO, contains high concentration of elastic fibers allowing it to SHRINK during extension |
What are the 3 main causes of spinal nerve compression within the intervertebral foramina (Dorsal Root Ganglia particularly vulnerable)? | 1.IV Disc bulge/herniation. 2.Osteophyte on edge of vertebrae. 3.Swelling/hypertrophy in joint capsule. |
What is the main way to distinguish Anterior Vs Posterior spinal cord? How can it be used to distinguish Ant Vs Post rootlets? | The Anterior Spinal Artery runs down along the spinal cord. If it is identified: 1.rootlets ANTERIOR to denticulate lig are Ant rootlets. 2.rootlets running POSTERIOR to denticulate lig are Post rootlets. **Vica Versa if posterior view. |
What is responsible for stabilizing the spinal cord within the spinal canal? | DURA. **Denticulate ligaments extend from Pia to Dura to stabilize the cord within the DURAL SAC. |
Where does the Dural sac end? Where does the spinal cord end? | S2. L1. |
What do the rootlets enter as they pass through the dura to leave the spinal column? What does that dura then become? | Lateral Recesses. After the intervertebral foramina, the dura turns into the EPINEURIUM. |
What Key structure does the needle pass through within the spinal column during an epidural injection? | Ligamentum Flavum. |
Where is the CSF contained within the spinal column? | Subarachnoid space, just like the brain. |
What structures would most likely impinge the dorsal root ganglia? | Intervertebral foramina. **Vertebral artery could in cervical vertebrae |
Which is larger, dorsal or ventral ramus? | Ventral Ramus is larger. **Dorsal and Ventral rootlets pass through lateral recesses together, then encounter the Dorsal Root Ganglia, then divide out. |
Compare and contrast the anatomy of the spinal cord in the cervical, thoracic and lumbar regions and relate these morphological features to functional issues | 1.Cervical: THICK (cervical enlargement) due to Inc sensory and motor neurons for the upper extremity. 2.Thoracic: THIN b/c less sensory & motor for Torso. 3.LumboSacral: THICK b/c lots of motor and senory neurons for lower extremity. |
Explain the orientation of rootlets in the cervical spine Vs thoracic,lumbar, and spine spine? Why is this? | 1.Cervical: Rootlets are horizontal. 2.Thoracic, Lumbar, Sacral: Rootlets are vertical. **This is because the spinal cord developes slower that spinal canal: Causes rootlets to stretch out more as you go down the cord. |
What spinal segements would you find in the Conus Medullaris? What type of damage would affect the Conus Medullaris? What symptoms would result? | Conus Medullaris is located at vertebral level T12 and constains spinal segements S2-S4. **Trauma at level T12 would damage it and cause both bladder and bowel control problems. |
At what level would a Lumbar Puncture be done? | Vertebral level L2. **Cauda Equina wont be damaged when you enter subarachnoid space here to remove the CSF. |
What is the extension of dura running from L1-S2 to anchor the dural sac to the sacrum? | Filum Terminale |
Describe the difference in spinal nerve exits seen in the spinal cord | 1.C1-C7 pass out above the equivalent transverse process. 2.C8: transition level. 3.T1-S5 pass out below equivalent transverse process. |
When will you see plexuses formed from spinal nerves? | At extremities. **Brachial and Lumbosacral |
What do the Dorsal Rami innervate? Ventral Rami? | DORSAL: Epaxial muscles (everything within the angle of the scapula developing posterior to transverse processes). VENTRAL:Hypaxial muscles (everything developing anterior to transverse processes). **Ventral will wrap back around to join Dorsal |
Do Cutaneous nerves follow along with dermatomes? Why or Why not? | NO. They contain innervation for multiple dermatomes b/c they cross through a PLEXUS. **they have mixed nerves so will contribute to multiple dermatomes. |
What is one important function of the Plexi seen at upper and lower extremities? | Allows the dermatomes to be maintained by different peripheral nerves. |