Neuro2 Flashcards
Where is the lesion in syringomyelia?
Anterior White Commissure
*Crossing fibers of Spinothalamic Tract
S/S of syringomyelia.
“Cape-like” bilateral los of Pain & Temp in Upper extremities
What is spared in syringomyelia?
Dorsal columns – Fine touch is preserved
Where in the vertebral column is syringomyelia most common?
C8-T1 (upper extremities)
Syringomyelia is associated with:
Chiari I malformation
Neuroectoderm gives rise to:
CNS neurons
Ependymal cells
Oligodendroglia
Astrocytes
Neural crest gives rise to:
PNS neurons
Schwann cells
Mesoderm gives rise to:
Microglia
“Microglia, like Macrophages, originate from Mesoderm”
What happens if an Axon is damaged?
Undergoes Wallerian degeneration
Function of Astrocytes.
Physical support & repair
K+ metabolism
NT removal
BBB maintenance
Function of Microglia.
CNS phagocyte
*HIV-infected macrophages fuse to form multinucleated giant cells in the CNS
What are the myelin producing cells in the CNS? PNS?
CNS - Oligodendrocytes
PNS - Schwann cells
What cells are destroyed in Multiple Sclerosis?
Oligodendrocytes
What cells are destroyed in Guillain-Barre syndrome?
Schwann cells
Acoustic Neuroma.
Type of Schwannoma
Located in Internal Acoustic Meatus (CN VIII)
Describe C-fibers.
Slow, Unmyelinated
Pain & Temp
Describe A(gamma) fibers
Fast, Myelinated
Pain & Temp
What receptor senses Dynamic, Fine/Light touch and position sense?
Meissner’s corpuscles
*Glabrous (Hairless) skin
What receptor senses Vibration & Pressure?
Pacinian corpuscles
*Deep skin layers, ligaments, joints
What receptor senses Pressure, Deep static touch (e.g., shapes, edges), position sense?
Merkel’s discs
*Hair follicles
What are the layers of a Peripheral Nerve?
- Endoneurium
- invests single nerve fiber layers
- Guillain-Barre
- Perineurium
- Permeability barrier
- surrounds fasicles
- must be rejoined in microsurgery
- Epineurium
- Dense CT that surrounds entire nerve
