Neuro Flashcards
Neural plate gives rise to…
Neural tube and neural crest cells
Notochord induces…
Overlying ectoderm to differentiate into neuroectoderm and form the neural plate
Notochord becomes…
Nucleus pulposus of IV disc in adults
Alar vs. Basal plate of primitive spinal cord derivatives
Alar: sensory
Basal: motor
What two serum/AF markers are present in NTD’s?
- AFP
2. AChE
The technical names for the fore/mid/hind-brain and their derivatives
Forebrain: Prosencephalon – Tel/Di
Midbrain: Mesencephalon – Mes
Hindbrain: Rhombencephalon – Met/Myel
Holoprosencephaly results from…
Failure of L-R separation (sonic)
Arnold-Chiari malformation
Chiari 2: cerebral aqueduct stenosis
A/W TL MMcele
Dandy-Walker Malformation
Agenesis of cerebellar vermis with cystic enlargement of 4th ventricle; fills enlarged posterior fossa
Anterior vs. Posterior tongue derived from what branchial arches?
Anterior: Arch 1
Posterior: Arch 3+4
Embryological origin CNS vs. PNS
CNS+ependymal+oligodendrocytes: Neuroectoderm
PNS+Schwann: Neural crest cells
Mesoderm: Microglial
Nissl substance stains…
RER of axons
Wallerian degeneration
Degeneration distal to the injury and axonal retraction proximally; allows for potential regeneration of axon (if in PNS)
Which cell in the CNS is responsible for physical support, K+ metabolism, removal of excess NT, maintenance of BBB and reactive gliosis?
Astrocytes
CNS phagocytes
Microglia
How do microglial respond to tissue injury?
Differentiate into large phagocytic cells
Nodes of Ranvier have high concentrations of what type of ion channel?
Sodium
What type of cell is destroyed in MS?
Oligodendrocyte
How many different types of cells does each oligodendrocyte/Schwann cell myelinate?
Oligodendrocyte: up to 50 axons
Schwann cell: 1 PNS axon
Shwann cells are destroyed in what condition?
GBS
Inflammatory infiltrate in GBS is in what layer?
Endoneurium
What layer of nerve must be rejoined in microsurgery for limb reattachment?
Perineurium
Dense C/T that surrounds entire nerve (fascicles and BV)
Epineurium
C fibers vs. A-delta fibers in free nerve endings
C: slow, unmyelinated
A-delta: fast, myelinated
Merkel’s discs vs. Meissner’s corpuscles
Meissner: Large, myelinated; fast adaptor [dynamic, fine touch] – hairless skin
Merkel: Large, myelinated; slow adaptor [static touch, position] – hair follicles
Free nerve endings sense
Pain and temperature
Pacinian corpuscles sense…
Pressure, vibration [deep skin layers, ligaments, joints]
Location synthesis: NE
Locus ceruleus (pons)
Location synthesis: Dopamine
Ventral tegmentum and SNc (MB)
Location synthesis: 5-HT
Raphe nucleus (pons)
Location synthesis: ACh
Basal nucleus of Meynert
Location synthesis: GABA
Nucleus acumbens
Stress and panic center of the brain
Locus ceruleus (pons)
Reward center, pleasure, addiction, fear in the brain
Nucleus accumbens
ACh increased/decreased in Alzheimer’s and Huntington’s
Decreased
NE increased/decreased in anxiety
Increased
Infarction and/or neoplasm destroying endothelial cell TJ’s results in
Vasogenic edema
Lateral hypothalamus
Hunger (inhibited by leptin)
Ventromedial hypothalamus
Satiety (Stimulated by leptin)
Anterior hypothalamus
Cooling (parasympathetic)
Posterior hypothalamus
Heating (sympathetic)
Suprachiasmatic nucleus hypothalamus
Circadian rhythm
Hypothalamus regulates
Thirst/H2O, Adenohypop, Neurohypop, Hunger, Autonomic, Temperature, Sexual
VPL, VPM, LGN, MGN, VL of the thalamus
VPL: DC/ML, ALS VPM: Trigeminal, gustatory LGN: CN2 --> calcarine sulcus MGN: SO/Inf. colliculus VL: Basal gangli
Major relay center for all ascending sensory information except olfaction
Thalamus
What system in the brain includes structures responsible for emotion, LTM memory, olfaction, behavior modulation, ANS system
Limbic system
Superior, Medial, Inferior cerebellar peduncles
Superior: output to contralateral cortex
Middle: input from contralateral cortex
Inferior [propioception]: input from SC [climbing/mossy fibers]
Describe cerebellar output
Purkinje fibers –> deep nuclei (lat to medial: DEGF) –> contralateral cortex
Lateral vs. Medial cerebellum
Lateral: voluntary movement
Medial: balance, truncal coordination
Essential (postural) vs. resting vs. intention tremor
Essential: familial, EtOH/beta-blocker, primidone
Resting: Parkinson’s
Intention: Cerebellar dysfunction
Hemiballismus is characterstically lesion of…
Contralateral subthalamic nucleus; lacunar stroke
Broca’s vs. Wernicke’s area
Broca: motor speech (formulation of speech)
Wernicke: associative auditory cortex (understanding)
Homunculus: medial vs. lateral (blood supply)
Medial: Anterior cerebral artery [toes, leg, shoulder, hand]
Lateral: Middle cerebral artery [face]
PPRF lesion vs. FEF lesion
PPRF: look away from lesion
FEF: look towards lesion
Amygdala lesion
Kluver-Bucy: hyperorality, hypersexuality, disinhibited behavior
Frontal lobe lesion
Disinhibition and deficits in [ ] & orientation, and judgement; may have reemergence of primitive reflexes
R parietal lobe lesion
Spatial neglect syndrome: agnosia of the contralateral side of the world
B/L Mammillary body lesion
Wernicke-Korsakoff: confusion, opthalmoplegia, ataxia, amnesia, confabulation, personality changes [B1 deficiency]
Cerebellar hemisphere vs. vermis lesion
Hemisphere: intention tremor, limb ataxia, loss of balance (ipsilateral)
Vermis: Truncal ataxia, dysarthria
Lesion to the subthalamic nucleus
Contralateral hemiballismus
Lesion to the hippocampus
Anterograde amnesia; inability to make new memories
Broca’s area
Inferior frontal gyrus
Wernicke’s area
Superior temporal gyrus of temporal lobe
Aphasia vs. Dysarthria
Aphasia: higher-order inability to speak (language)
Dysarthria: motor inability to speak (movement)
Global vs. Conduction aphasia
Global: Broca’s + Wernicke’s
Conduction: Poor repetition but fluent speech; damage to arcuate fasiculus
If a patient cannot repeat the phrase: No if’s, ands, or buts… There is damage to
Arcuate fasiculus
Hypoxemia increases cerebral perfusion pressure only when PO2 < ______ mm Hg
50
