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Flashcards in Neuro Deck (48):
1

Neuron staining

Nissl stain - stains RER

Doesn't stain axons, there isn't any RER there!

2

Axonal injury

Wallerian degeneration - distal degen, retraction proximally

If PNS, potential regeneration

3

Astrocytes
give functions, stain, derivation

Physical support, repair, K+ metabolism
necessary for blood-brain barrier
- holds glycogen fuel reserve

-marker GFAP
-reactive gliosis
-derived from neuroectoderm!

4

Microglia

scavenger cells of CNS
- mesodermal mononuclear origin
- HIV: fuse to form multinucleated giant cells
- not stained by Nissl

5

Schwann cell

1:1 ratio with PNS cells
- promote axonal regeneration
- neural crest!

destroyed in Guillain-Barre syndrome
- acoustic neuroma

6

Oligodendrocytes

1:many ratio with CNS cells
- injured in MS, PML
- neuroectoderm
- fried egg appearance

7

Peripheral nerve structure
Endoneurium
Perineurium
Epineurium

Endoneurium: single nerve fibers (site of inflamm infiltration in G-B)
Perineurium: surrounds fascicle of nerve fibers, rejoined in microsurgery in limb attachment
Epineurium: dense connective tissue, contains fibers and blood vessels

8

Blood brain barrier (3 things)

Tight junctions (endothelial cells)
Basement membrane
Astrocyte foot processes

- glucose/AAs cross slowly
- non-polar/lipid-soluble cross rapidly
- no BBB: area postrema, neurohypophysis

9

Hypothalamus (regulates TAN HATS, give hormones and site of synthesis)

Thirst, Adenohypophysis, Neurohypophysis, Hunger, Autonomic regulation, Temp regulation, Sexual urges

Supra optic nucleus: ADH
Paraventricular: oxytocin

Inputs: area postrema, OVLT = osmolarity sensor

10

Nuclei of hypothalamus
Lateral
Ventromedial
Ant. hypot
Post. hypot
Suprachiasmatic

Lateral: hunger
Ventromedial: satiety
Ant. hypot.: cooling/parasympathetic
Post. hypot: heating, sympathetic
Suprachiasmatic: ciracidan rhythms (sleep = charismatic)

11

Sleep physiology

Light --> suprachiasmatic nucleus --> NE --> pineal gland --> melatonin

12

Thalamus nuclei
VPL
VPM
LGN
MGN
VL

- relay for all sensory information except olfaction
VPL: STT/DCML tracts (everything but face!)
VPM: trigeminal/gustatory (face sensation, taste)
LGN: vision (L for light!)
MGN: hearing
VL: basal ganglia, cerebellum

13

Limbic system functions (5 F's)

feeding
fleeing
fighting
feeling
sex

14

Cerebellum inputs, outputs, lesions

Input:
- middle cerebellar peduncle = contralateral cortex
- inferior cerebellar peduncle = ipsilateral proprioceptive

Output:
- superior cerebellar peduncle = contralateral cortex to modulate movement

Lesions: lateral will fall to affected side, medial will be truncal ataxia

15

Basal ganglia anatomy

Describe direct and indirect pathways

Striatum = putamen (motor input) + caudate (cognitive input)
Motor functions all start in the frontal cortex

Direct pathway = D1R leads to increased GABA from striatum to inhibit GPi inhibitory neurons, leading to increased thalamus activity and increased movement

Indirect pathway = D2R leads to inhibition of GPe, releasing their inhibition of subthalamic nucleus, allowing for activation of GPi and inhibition of thalamus

16

Parkinsons

decreased DA secretion, leads to overall less movement and also less inhibition of movements at rest

-alpha synuclein form Lewy bodies (eosinophilic, intracellular inclusions)

TRAPS: tremor, rigidity, akinesia, postural instability, shuffling gait

17

Huntinton

CAG repeats
Caudate loses Ach and GABA

18

Aphasia
Broca
Wernicke
Conduction
Global motor
Global sensory

Broca - nonfluent, impaired repetition (inferior frontal gyrus)
Wernicke - fluent, impaired comp/rep (superior temporal gyrus)
Conduction - fluent, poor rep (arcuate fasciculus)
Global motor - nonfluent, intact otherwise
Global sensory - poor comp, intact everything

19

Amygdala lesions

Hyperphagia, hypersexuality, hyperorality (HSV-1 = infectious cause)

20

Parietal-temporal lesions

Contralateral hemispatial neglect

21

Midbrain
Reticular-activating system lesions

Decreased arousal, wakefulness

22

Mamillary bodies lesions

W-K syndrome, confabulation!

23

Subthalamic nucleus lesions

Contralateral hemiballismus

24

Hippocampus lesions

anterograde amnesia

25

Frontal eye fields lesions

Conjugate toward the side of the lesion

26

Cerebral perfusion

Driven by pCO2 (central medullary chemoreceptors)
CPP = MAP - ICP

27

Medial medullary syndrome

Paramedian ASA branches infarct
Leads to hemiparesis, decreased proprioception, hypoglossal dysfunction (tongue motor symptoms)

28

Lateral medullary syndrome

PICA or verterbral artery
CN V, VII, VIII, IX, X, XII all affected
vomiting, vertigo, nystagmus, HOARSENESS, DYSPHAGIA

29

Lateral pontine syndrome

AICA
Paralysis of face, decreased lacrimation/salivation

30

Epidural hematoma

Middle meningeal, lucid interval, III palsy,

transtentorial herniation

31

Subdural hematoma

bridging veins, slow evolving

32

Subarachnoid hemorrhage

Saccular aneurysm rupture (Ehlers-Danlos, ADPKD)
Xanthochromic LP

33

Intraparenchymal hemorrhage

Systemic hypertension, amyloid angiopathy
Most often in the basal ganglia or internal capsule

34

Ischemia histology progression

12-48 hrs: red neurons
24-72 hrs: necrosis, neuts
3-5 days: macrophage/microglia infiltration
1-2 weeks: reactive gliosis
>2 weeks: scar

35

Pseudotumor cerebri dx, findings, risk factors

increased ICP w/o evidence of cause
Diplopia (VI palsy), papilledema
Risk factors: Vitamin A excess, danazol (endometriosis drug)
Tx: weight loss, acetazolomide, topiramate, shunt

36

Polio/SMA effect on spinal cord

LMN damage, destruction of anterior horn

37

ALS effect on spinal cord

Super oxide dismutase, UMN and LMN lesions

38

B12 deficiency effect on spinal cord

demyelination of dorsal columns, lateral corticospinal tracts

39

Polio

LMN death in anterior horn
Virus recovered from stool/throat

40

Friedrich ataxia

GAA on ch. 9 (frataxin)
- staggering gait, falling, hypertrophic cardiomyopathy

41

Reflexes

Biceps: C5
Triceps: C7
Cremaster: L1
Patella: L4
Achilles: S1
Anal: S3

42

Superior colliculi

Conjugate vertical gaze cetner
Parinaud syndrome = lesion, paralysis of conjugate gaze

43

Middle cranial fossa pathways

Optic canal: CN 2
Superior orbital fissure: CN 3, 4, 5-1, 6
Foramen rotundum: V2 (maxillary)
Foramen ovale: V3 (mandibular)
Foramen spinosum: middle meningeal

44

Posterior cranial fossa pathways

Internal auditory meatus: CN 7, 8
Jugular foramen: Cn 9, 10, 11, jugular vein
Hypoglossal: 12
Foramen magnum: 11 (spinal levels only)

45

Vagal nuclei

Nucleus solitarius - visceral sensory info
Nucleus ambiguus - motor innervation of pharynx/larynx/upper esophagus
Dorsal motor nucleus - parasympathetics to heart/lungs/upper GI

46

Cavernous sinus

either side of the pituitary, collect blood from the eyes to the internal jugular
- CN 3, 4, 5-1, 6 and sympathetic fibers
- also, internal carotid
- syndrome: ophthamloplegia, decreased corneal sensation, Horner syndrome, CN 6 most susceptible

47

Inner ear

low freq = apex near helicotrema (wide, flexible)
high freq = base of cochlea (thin, rigid)

Stapes hits the oval window to stimulate inner ear

48

Muscles of mastication

closes: masseter, temporalis, medial pterygoid
opens: lateral pterygoid

V3 nerve