Neurology Flashcards
Astrocyte
Physical support Repair K+ metabolism Removal of excess neurotransmitters Component of blood brain barrier
Microglia
CNS phagocyte, derived from monocytes
Irregular nuclei, little cytoplasm, no discernible w/ Nissel stain
HIV infected microglia fuse to form multinucleate giant cells in the CNS
Oligodendroglia
Mylinates the axons of neurons in the CNS
Each oligodendroycte can myelinate many axons
Predominant type of glial cell in white matter
“Fried egg” appearance on H&E
Destroyed in MS and PML
Schwann cells
Each Schwann cell myelinated only 1 PNS axon
Also promotes axonal regeneration
Destroyed in GBS
Free nerve endings
C (slow), Adelta (fast)
Located in skin, epidermis, and some vicera
Pain and temperature
Meissner corpuscles
Large myelinated fibers, adapt quickly
Hairless skin
Dynamic, fine/light touch, position sense
Pacinian corpuscles
Large myelinated fibers, adapt quickly
Deep skin layers, joints
Vibration, pressure
Merkel discs
Large myelinated fibers, adapt slowly
Basal epidermal layer, hair follicles
Pressure, deep static touch, position sense
Right parietal temporal cortex lesion
Spatial neglect syndrome
Agnosia of the contralateral side of the world
Left parietal temporal cortex lesion
Gerstmann syndrome
Agraphia, acalculia, finger agnosia
Reticular activating system (midbrain) lesion
Reduced levels of arousal and wakefulness
Mammillary bodies lesions
Associated w/ thiamine deficiency
Wernicke-Korsakoff syndrome
Cerebellar hemisphere lesions
Intention tremor, limb ataxia, loss of balance
Fall toward side of lesions
Laterally located affecting lateral limbs
Cerebellar vermis lesions
Truncal ataxia, dysarthria
Centrally located, affects central body
Central pontine myelinolysis
Variant of osmotic demyelination syndrome
Acute paralysis, dysarthria, dysphagia, diplopia, and loss of consciousness
CAN cause locked in syndrome
Massive axonal demyelinaiton in pontine whir matter tracts 2ndary to osmotic forces and edema
Commonly iatrongenic, caused by overly rapid correction of hyponatremia
Broca aphasia
Broca Broken Boca (mouth)
Nonfluent aphasia with intact comprehension
Broca area: inferior front gyrus of front lobe
Wernicke aphasia
Wordy but makes no sense
Fluent aphasia with impaired comprehension and repetition
Wernicke area: superior temporal gyrus of temporal lobe
Global aphasia
Nonfluent aphasia with impaired comprehension
Both Broca and Wernicke areas affected
Conduction aphasia
Poor repetition but fluent speech, intact comprehension
Can be caused by damage to left superior temporal lobe and/or left supramarginal gyrus