Card Set Information
Which has the ability to regenerate? CNS or PNS
PNS, nerves regrow at 3mm/day
The supporting glial cell of the CNS both structurally and metabolically; contains GFAP marker useful in identifying tumors
phagocytic cells of the CNS
myelin-forming cells of the CNS; 1 cell can myelinate up to 30 axons
myelinating cells of the PNS; 1 Schwann cell produces 1 internode
line central canal and ventricles; produce CSF
Neurofibromatosis, type 1
Gliomas of optic nerve, pigmented lesions of iris (Lisch nodules) and cafe‐au‐lait spots
NF1 gene at 17q11.2 – neurofibromin – tumor suppressor gene
Neurofibromatosis, type 2
Bilateral schwannomas and multiple meningiomas may occur
Gliomas (ependymomas of spinal cord)
NF2 gene at 22q12 ‐ merlin
Hamartomas of brain – cortical tubers and subependymal hamartomas (candleguttering)
Organ cysts, angiofibromas, shagreen and ash‐leaf (skin) patches, and subungual fibromas.
Genes – TSC1 at 9q34 – hamartia; TSC2 at 16p13.3 – tuber in
Subependymal giant cell astrocytomas can occur
Hemangioblastoma – cerebellum, retina, brain, spinal cord)
Pancreas, liver, kidney cysts
Renal cell carcinoma
Gene on chromosome 3p25‐26 coding pVHL
Hemangioblastoma cells produce erythropoietin – polycythemia
Venous angiomatous masses in leptomeninges
Ipsilateral port‐wine stain of face
Mental retardation, seizures, hemiplegia, radiopacities in skull
Which tract carries parasympathetics to S2-S4? What happens when this tract is severed?
Corticospinal tract to the sacral nerves; loss of voluntary bladder and bowel control.
Which spinal tracts are affected in with vitamin B12 neuropathy (aka: subacute combined degeneration)?
Dorsal columns, lateral corticospinal tracts, spinocerebellar tracts (arm/leg dystaxia)
Guillain-Barre syndrome: which nerves are affected?
motor fibers of ventral roots and peripheral nerves producing LMN symptoms (m weakness, ascending flaccid paralysis, areflexia)
Guillain-Barre syndrome: Features
Demyelination and edema
Upper cervical root (C4) involvement and respiratory paralysis
Facial diplegia (CN involv)
Elevated protein (causing papilledema)
Increased CSF protein w/o pleocytosis (albuminocytologic dissociation)
where does spinal cord end on infants and adults?
Disk herniation between L4 and L5: which spinal nerve will be affected?
L5; the spinal nerves T1-S4 come out below their corresponding vertebrae; the lumbar nerves cross over the junction above the corresponding vertebrae
Disk herniation between C5 and C6: which nerve is affected?
C6; the spinal nerves C1-C7 emerge above their corresponding vertebrae but unlike T and L spinal herniations, Cervical herniations affect the nerve emerging at that junction
Conus medullaris syndrome (S3-coccygeal)
Results in bilateral pain, normal reflexes, incontinence and sexual functions impaired, onset sudden and bilateral
Cauda Equina syndrome (L3-Coccygeal)
unilateral pain, unilateral muscle atrophy and absent lower reflexes (S1 and L3)
Explain corticobulbar innervation of facial nerve nucleus
Facial nerve nucleus that innervates the upper face receives bilateral corticobulbar input
Facial nerve nucleus that innervates the lower face receives only contralateral corticobulbar input
With trigeminal sensation, which is contralateral vs. ipsislateral: pain and temp (ventral) vs. discrimination and pressure (dorsal)?
pain and temp
: contralateral, 2nd order fibers decussate in lower medulla
discr. and pressure
: ipsilateral, 2nd order nuclei are in the principal sensory nucleus of V
What is the drug of choice for Tic douloureux?
Functions of CN VII
taste (ant 2/3)
general sensation from external ear
Stapedius m (hyperacusis if paralyzed)
lacrimation during eating as a result of aberrant regeneration after trauma
3 Things required for balance
Functions of CN IX
Taste and general sensation (post 2/3)
Input from carotid sinus and body
Functions of CN XI
Cranial division-n.ambiguus-intrinsic mm of the larynx via inferior (recurrent laryngeal nerve) except cricothyroid m.(CNX)
Spinal division-from C1-C6-sternocleidomastoid and trapezius
Inferior (Recurrent) laryngeal nerve->intrinsic larynx mm