Neurology Flashcards
What type of neuronal cell has a different embryonic origin than the rest?
Microglia - from mesoderm; CNS macrophage
Others are from neuroectoderm
Stains for different cells?
Nissl substance = dendrites, cell bodies (RER) - NOT axons
GFAP = astrocytes
Blood Brain Barrier
- tight junctions nonfenestrated endothelial cells
- BM
- astrocyte foot process
Lipids get through
Glucose/AA need carriers
NOT present in area postrema and neurohypophysis
Lateral Area Hypo
Hunger
Inhibited by Leptin
Destruction: anorexia, FTT
Ventromedial Area Hypo
Satiety
Stimulated by Leptin
Destruction: obesity, hyperphagia
Anterior Hypothalamus
Cooling, PNS
“Anterior nucleus = A/C”
Posterior Hypothalamus
Heating, Symp
Suprachiasmatic Nucleus
Circadian Rhythm
Stimulates pineal gland -> melatonin
Preoptic Area Hypothalamus
GnRH
Dorsomedial Nucleus
Stimulates GI - savage behavior, obesity
Arcuate Nucleus
Dopamine
GHRH
Supraoptic Nucleus
ADH
Paraventricular Nucleus
Oxytocin
Stages of Sleep and EEG waveform
“BATS Drink Blood”
Awake (open eyes) = beta (highest freq, lowest amp)
Awake (closed eyes) = alpha
N1 light sleep = theta
N2 deeper sleep; bruxism = sleep spindle, K complexes
N3 deepest/slow wave sleep = delta (lowest freq, highest amp)
REM = beta
What stage of sleep associated with night terrors, sleep walking, bedwetting? What drugs treat?
N3
EtOH, Benzo, Barb = decreased REM and delta sleep
Bedwetting = DDAVP
What happens during REM sleep?
loss of motor tone variable pulse, BP dreaming penil/clitoral tumescence memory processing
What characterizes narcolepsy? What stage? Tx?
Awake -> REM sleep:
- excessive daytime sleepiness
- cataplexy
- HypnoGOgic (going to sleep); HypnoPOmpic (post sleep) hallucinations
Tx:
- stimulants: amphetamine, modafinil
- PM sodium oxybate GHB
Changes in sleep stages in depression?
- dec. slow wave N3 deep sleep
- inc. total REM
- rpted PM awakenings
- early AM awakening
Kallman Syndrome?
Dec. GnRH (Hypogonadism) + Anosmia
Corneal & Lacrimation Reflex
CN V1
CN VII
Jaw Jerk Reflex CN
V3
Pupillary Reflex CN
CN II
CN III
Gag Reflex CN
CN IX
CN X
Mnemonic for S vs. M in CN?
Some Say Marry Money But My Brother Says Big Brains Mean More
CN Pathway
1 Cribiform Plate 2 Optic Canal 3, 4, 6, V1 Superior Orbital Fissure V2 Foramen Rotundum V3 Foramen Ovale 7, 8 Internal Auditory Meatus 9, 10, 11 Jugular Foramen 12 Hypoglossal Canal
Foramen Magnum = spinal roots of Cn XI, Brain stem, VA
V = Standing Room Only
Damage to CN III vs. IV vs. VI?
CN III: “Down and out,” ptosis, mydriasis, loss of accommodation
CN IV:
- eye moves upward
- esp with contralateral gaze
- compensatory head tilt TOWARD side of the lesion
CN VI:
- medial eye, can’t abduct
- Obliques move the eye in the Opposite direction”
Afferent vs. Efferent Pupillary Eye Defect?
Afferent = Marcus Gunn Pupil = Optic N. damage
- affected eye: nothing constricts with light
- unaffected eye: both will constrict with light
Efferent = Oculomotor N.
- affected eye UNABLE to constrict with light in EITHER eye
Meyer vs. Dorsal Optic Radiation?
Meyer = temporal loop
Dorsal Optic = parietal loop
Forebrain (Prosencephalon)
Telencephalon = Cerebral Hemispheres; Lateral ventricles Diencephalon = Thalamus; 3rd ventricle
Midbrain (Mesencephalon)
Mesencephalon = Midbrain; aqueduct
Hindbrain (Rhomboencephalon)
Metencephalon = Pons, Cerebellum, upper 4th ventricle Myelencephalon = Medulla, lower 4th ventricle
Screening for NT defects
When do neuropores normally fuse?
Elevated AFP in maternal serum or amniotic fluid
4th week
Spina Bifida Occulta vs. Meningocele vs. Myelomeningocele
Spina Bifida Occulta - opening in bone spinal canal, tuft hair/dimple, nl AFP
Meningocele - meninges out
Myelomeningocele - meninges + spinal cord out
Anencephaly associated with what condition?
Failure of anterior NT to close - inc. AFP
Polyhydramnios (no swallowing center)