Lesson1 Flashcards
Meninges
- 3 connective tissue coverings
(epidural space)
- Dura Mater
(subdural space)
- Arachnoid Mater
(subarachnoid space)
- Pia Mater
What protects the spinal cord?
Bony vertebral column
Meninges
Space with CSF
Dura mater
Superficial
Dense Irregular CT
Arachnoid Mater
Middle layer
Avascular
Delicate collagen fibers and elastic fibers
Pia Mater
Innermost layer
thin and transparent
adheres to spinal cord and brain
lots of blood vessels to supply spinal cord
Denticulate Ligaments
Extensions of Pia Mater that suspend the spinal cord in the middle
Protect against sudden displacement
Spinal Cord Shape
Oval (flattened anteriorly and posteriorly)
Spinal Cord Length
Medulla Oblongata to L2
In newborns L3 or L4
2 Enlargements of the SC
- Cervical enlargement
* C4 to T1
* Nerves to and from Arms - Lumbar enlargement
* T9-T12
* Nerves to and from legs
Conus Medullaris
End of the spinal cord
Ends between L1 and L2
Filum Terminale
Extension of Pia mater that runs from conus medullaris to coccyx
Cauda Equina
Spinal Nerve roots at the end of the spinal cord that fan out like a horses tail
Do not exit the vertbral column at the same level they exit the cord
How many Cervical spinal nerves are there
8
C1-C8
What is a Spinal Tap
Anasthetic inserted in the subarachnoid space to withdraw CSF
Patient side lying and flexed
Normally performed between L3-L4 or L4-L5
White Matter
Bundles of myelinated axons
Grey Matter
Dendrites and cell bodies of neurons
Unmyelinated axons
Posterior Grey Horns
- Incoming sensory axons
- Cell bodies of interneurons
Anterior Grey Horns
- Somatic motor cell bodies
Lateral Grey Horns
- Only in thoracic and upper lumbar spine
- Autonomic motor cell bodies
Tracts
Bundles of Axons in the CNS
Nerves
Bundles of axons in the PNS
Nuclei
Clusters of cell bodies in the CNS
Ganglion
Clusters of cell bodies in the PNS
Spinal nerve coverings
deep to superficial
- Endoneurium
- Perineurium
- Epineurium
Endoneurium
- innermost layer
- wraps individual axon
Perineurium
- Middle layer
- Wraps fascicles
Epineurium
- Outer layer
- Wraps entire nerve
Neurapraxia
6 points
- First degree nerve injury
- Mild focal compression
- Segmental demyelination
- Reversible in hours to months
- No break in the fiber
- Motor function loss
Axonotmesis
6 points
- Second degree nerve injury
- prolonged, severe compression
- Wallerian degeneration
- Endoneurium intact
- Prognosis >6mo
- sensory, motor, autonomic loss
Neurotmesis
5 points
- third degree nerve injury
- damaged endoneurium
- Wallerian degeneration
- Hard to regenerate
- Surgical intervention to suture
