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Flashcards in Neuro Deck (75):
1

Forebrain derivatives

- telencephalon (cerebral hemispheres)
- diencephalon (thalamus)

2

midbrain derivatives

- mesencephalon (midbrain)

3

Hindbrain derivatives

- metencephalon (pons, cerebellum)
- myelencephalon (medulla)

4

Neural tube defect findings

- increased AFP and AchE (confirmatory test)

5

spina bifida

- failure of bony spinal canal to close, no herniation
- tuft of hair overlying defect
- dura is intact

6

meningocele

- meninges (but not the spinal cord) herniate through spinal canal defect
- normal AFP

7

meningomyelocele

- meninges and spinal cord herniate through spinal cord defect

8

anencephaly

- malformation of anterior neural tube
- increased AFP, polyhydramnios (no swallow center)
- associated with type I DM and decreased folate

9

Arnold Chiari I malformation

- cerebellar tonsillar ectopia (congenital malformation that is usually asyptomatic, but can manifest with headache and cerebellar symtpoms)
- associated with syringomyelia

10

Arnold Chiari II malformation

- signficant herniation of cerebellar tonsils and vermis through foramen magnum with aqueductal stenosis and hydrocephalus
- often presents with lumbosacral myelomeningocele and paralysis below the defect

11

Dandy-Walker malformation

- agenesis of vermis, with cystic enlargement of 4th ventricle
- associated with hydrocephalus and spina bifida

12

syringomyelia

- cystic cavity within the spinal cord
- crossing anterior spinal commissural fibers are typically damaged first
- results in "cape-like" bilateral loss of P/T sensation
- late stage can progress to lower extremity weakness and hyperreflexia

13

tongue innervation

- ant 2/3 - V3 sensation and VII taste
- post 1/3 - IX sensation and taste
- XII movement

14

neurons

- if the axon is injured, undergoes Wallerian degeneration
- neuronal marker is synaptophysin

15

astrocytes

- supporting cell that is a component of the BBB
- responsible for reactive gliosis in response to neuronal injury
- marker - GFAP
- derived from neuroectoderm

16

microglia

- CNS phagocytes
- mesodermal origin
- respond to tissue damage by differentiating into large phagocytic cells

17

myelin

- CNS - oligodendrocytes
- PNS - schwann cells
- increase space constant (length constant) and conduction velocity

18

oligodendroglia

- derived from neuroectoderm
- "fried egg" appearance
- myelinate many different axons in the CNS
- damaged in MS, PML and leukodystrophies

19

schwann cells

- each cell myelinates only one PNS axon
- derived from neural crest
- destroyed in GBS
- acoustic neuromas are schwannomas

20

free nerve endings

- C - slow, unmyelinated fibers
- Ad - fast, myelinated fibers
- located in all skin, epidermis and some viscera
- senses pain and temp

21

meissner corpuscles

- large, myelinated fibers
- adapt quickly
- located in glabrous (hairless) skin
- senses dynamic, fine/light touch, position sense

22

pacinian corpuscles

- large, myelinated fibers
- adapt quickly
- located in deep skin layers, and joints
- sense vibration, pressure

23

merkel discs

- large, myelinated fibers
- adapt slowly
- located in basal epidermal layer, hair follicles
- sense pressure, deep static touch, and position sense

24

TTX and Saxitoxin effect

- blocks Na channels, inhibiting influx and preventing AP conduction

25

Norepinephrine

- locus ceruleus (pons)
- increased in anxiety, decreased in depression

26

dopamine

- ventral tegmentus and SNc
- increased in Huntingtons, decreased in parkinsons and depression

27

5HT

- raphe nucleus
- plays a role in sleep/wake cycle - lesions lead to insomnia and depression
- increased in parkinsons, decreased in axiety and depression

28

Ach

- basal nucleus of Meynert
- increased in parkinsons, decreased in Alzheimers, decreased in HD

29

GABA

- nucleus acumbens
- decreased in anxiety, decreased in Huntington disease

30

Hypothalamus functions

TAN HATS
- Thirst/water balance
- Adenohypophysis control
- Neurohypophysis releases hormones made in the hypothalamus
- Hunger
- Autonomic regulation
- Temp regulation
- Sexual urges

31

supraoptic nucleus of the hypothalamus

makes ADH

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paraventricular nucleus of the hypothalamus

makes oxytocin

33

lateral area of the hypothalamus

mediates hunger
- lesions --> anorexia, inhibited by leptin
- if you zap your lateral nucleus, you shrink laterally

34

ventromedial area of the hypothalamus

medaties satiety
- lesions --> hyperphagia, stimulated by leptin
- if you zap your ventromedial nucleus, you grow ventrally and medially

35

anterior hypothalamus

- cooling, parasympathetic
- lesions lead to hyperthermia
- Anterior is the A/C

36

posterior hypothalamus

- heating, sympathetic
- lesions lead to hypothermia
- if you zap the posterior, you become a poikilotherm

37

suprachiasmatic nucleus of the hypothalamus

- circadian rhythm
- you need to sleep so you can be charismatic

38

waves of sleep phases

BATS Drink Blood
awake (eyes open) - beta
awake (eyes closed) - alpha
Stage 1 - Theta
Stage 2 - Sleep spindles and K complexes
Stage 3 - Delta
REM - beta

39

VPL thalamus

- input from spinothalamic tract and dorsal columns
- pain and temp, pressure, touch, vibration and proprioception
- transmits to the primary somatosensory cortex

40

VPM thalamus

- input from trigeminal and gustatory pathway
- face sensation and taste
- transmits to primary somatosensory cortex
- vpM - Makeup goes on the face

41

LGN thalamus

- input from CN II
- vision
- goes to calcarine sulcus
- Lateral = Light

42

MGN thalamus

- input from superior olive and inferior colliculus of the tectum
- hearing
- goes to auditory cortex of temporal lobe
- Medial = Music

43

VL thalamus

- input from basal ganglia, cerebellum
- receives motor information
- destination -- motor cortex

44

basal ganglia

- Direct pathway - via D1 receptors - stimulates movement
- indirect pathway - via D2 receptors - inhibits movement
- SNc inputs on D1/D2 receptors in putamen, then to GP and on to thalamus

45

Parkinson disease

- degenerative disease of Lewy bodies
- loss of dopaminergic neurons in the SN pars compacta
- TRAPS - tremor, rigidity, akinesia, postural instability, shuffling gait

46

Huntington disease

- CAG repeat on chromosome 4
- huntington protein deacetylates histones - silencing genes that are needed for neuronal survival -- neuronal death via NMDA-R binding and glutamate toxicity
- decreased levels of GABA and Ach in the brain
CAG repeats - Caudate loses Ach and GABA

47

hemiballisumus

sudden, wide flailing of 1 arm +/- ipsilateral leg
- lesion: contralateral subthalamic nucleus (lacunar stroke)

48

chorea

sudden, jerky, purposeless movements
- lesion: basal ganglia (HD)

49

amygdala lesion

Kluver Bucy syndrome - hyperorality, hypersexuality, disinhibited behavior

50

right parietal-temporal cortex lesion

spatial neglect syndrome (agnosia of contralateral world)

51

left parietal-temporal cortex lesion

agraphia, acalculia, finger agnosia, and L/R disorientation

52

subthalamic nucleus lesion

contralateral hemiballismus (lacunar stroke)

53

paramedian pontine reticular formation

eyes look away from the side of the lesion

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frontal eye fields

eyes look toward the side of the lesion

55

brocas area

inferior frontal gyrus of frontal lobe

56

wernickes area

superior temporal gyrus of temporal lobe

57

conduction aphasia

- poor repetition but fluent speech and intact comprehension
- due to lesions of the left superior temporal lobe or left supramarginal gyrus

58

ACA stroke

- affects the motor and sensory cortices of the contralateral lower limb

59

lenticulostriate artery stroke

- affects the striatum, internal capsule
- contralateral hemiparesis, hemiplegia
- common location of lacunar infarcts 2/2 uncontrolled hypertension

60

ASA stroke

- affects the lateral corticospinal tract, medial lemniscus and caudal medulla - hypoglossal nerve
- causes contralateral hemoparesis, upper and lower limbs
- decreased contralateral proprioception
- ipsilateral hypoglossal dysfunction

61

PICA stroke

- lateral medulla
- vomiting, vertigo, nystagmus, decreased pain and temp sensation from ipsilateral face and contralateral body
- dysphagia, hoarseness, decreased gag reflex, ipsilateral Horner syndrome, ataxia, dysmetria

62

AICA stroke

- lateral pons and medial/inferior cerebellar peduncles
- vomiting, vertigo, nystagmus, paralysis of the face, decreased lacrimation, salivation, taste and corneal reflex
- face - decreased pain and temp, ipsilateral decreased in hearing and Horners
- ataxia, dysmetria
- "facial droop means the AICA's pooped"

63

PCA stroke

- occipital cortex, visual cortex
- contralateral hemianopia with macular sparing

64

basilar artery stroke

- post, medulla, lower midbrain, etc
- "locked in syndrome" - preserved cognition and blinking with quadraplegia

65

PCOM aneurysm

CN III palsy - down and out eye with ptosis and pupil dilation

66

berry aneurysms

- most commonly at the ACA and ACOM junction
- associated with ADPKD, Ehlers Danlos and Marfans

67

Charcot-Bouchard aneurysm

- associated with chronic HTN, affects small vessels (basal ganglia, thalamus)

68

first area to be damaged in global cerebral hypoperfusion

hippocampus

69

central post-stroke pain syndrome

neuropathic pain due to thalamic lesions (starts as numbness, progresses to allodynia)

70

intraparenchymal hemorrhage

- most commonly caused by systemic HTN, also amyloid angiopathy, vasculitis and neoplasm
- typically happens in the basal ganglia and internal capsule, but can be lobar

71

12-48 hours after brain ischemia

red neurons (eosinophilic cytoplasm, pynknotic nuclei, decreased Nissl)

72

24-72 hours after brain ischemia

necrosis and neutrophils

73

3-5 days after brain ischemia

macrophages

74

1-2 weeks after brain ischemia

reactive gliosis and vascular proliferation

75

> 2 weeks after brain ischemia

glial scar