Review Deck Flashcards
What is the red nucleus? what part of brainstem?
midbrain
cerebellar motor control
What is in the tectum of midbrain?
quadreminal plate –> superior and inferior colliculi
What separates the tectum from tegmentum?
cerebral aqueduct
What 2 cranial nerve nuclei in midbrain?
CN III and IV
what cranial nerve nuclei in pons?
CN V, VI, VII, VIII
What cranial nerve nuclei in medulla?
IX, X, XII
What is edinger wetphal nucleus?
- nucleus for CN III
- in midbrain
- responsible for pupil contraction, ciliary body
What is solitary nucleus?
- Sensor, cardiorespiratory [baroreceptors] and taste
- CN VII, IX, X
What is nucleus ambiguous?
- Motor, responsible for swallowing
- CN IX, X
WHere is nucleus of CN IX?
spinal cord
What is basal plate vs alar plate?
Lateral nuclei = sensory = aLar plate
Medial nuclei = Motor = basal plate
Where is 4th ventricle with respect to quadrigeminal plate?
inferior to it
Which 3 CNs lie medial at the brainstem?
3, 6, 12
3x2 = 6x2 = 12
What happens in CN V motor nerve lesion?
jaw deviates toward side of lesion
What happens in CN X nerve lesion?
uvula deviates away from side of lesion
What happens in CN XI lesion?
weakness turning head to contralateral side, shoulder droop on same side as lesion
What happens in CN XII lower lesion?
tongue toward side of lesion “lick your wound”
What happens in facial upper motor neuron lesion?
lower face: contralateral paralysis
upper: spared due to bilateral UMN innervation
What happens in facial lower motor neuron lesion?
ipsilateral paralysis of both upper AND lower face
What happens in facial nerve palsy?
- complete destruction of facial nucleus
- ipsilateral facial paralysis, can’t close eye on involved side
“bell’s palsy”
What type of astrocytes in grey vs white matter?
grey = protoplasmic white = fibrous
What are the 3 types of glutamate receptors we talked about?
AMPA: ionotropic, Na/Ca
NMDA: ionotropic, Na/Ca, blocked by Mg/alcohol/PCP, need glycine co-activation
mGluR1-8: metabotropic, autoreceptor
What is the nucleus accumbens [2 functions]?
- site of GABA synthesis in brain
- innervated by mesolimbic dopamine pathway for emotion/reward
- in basal forebrain/ganglia rostral to hypothalamus
What are 2 types of GABA receptors
GABA-A: ionotropic, Cl-, increased by hypnotics, decreased by convulsants, rapid
GABA-B: metabotropic, modulatory, autoreceptor
What is the major glycine receptor?
strychnine-sensitive glycine receptor: ionotropic, Cl-
What is function of glycine in brain?
- co-agonist for NMDA glutamate receptor
thus modulates glutamate transmission in brain
What are 3 major sites of dopamine synthesis?
- arcuate nucleus of hypothalamus
- substantia nigra of midbrain
- ventral tegmental area [VTA] of midbrain
What is substantia nigra?
- part of basal ganglia of midbrain
- site of dopamine synthesis
- start of nigrostriatal dopaminergic pathway that innervates striatum
What is ventral tegmental area?
- ventral part of tegmentum of midbrain
- site of dopamine synthesis
- start of mesolimbic dopaminergic pathway that innervates nucleus accumbens [for reward/emotion]
What is arcuate nucleus?
- part of tubular region of hypothalamus
- site of dopamine synthesis
- start of tuberoinfundibular pathway that innervates AP [to inhibit prolactin secretion]
What two structures make up the striatum?
- putamen and caudate nucleus
What two structures make up the lenticular nucleus?
- putamen and globus pallidus
What is function of dopamine nigrostriatal path?
extrapyramidal motor function
What is function of mesocorticolimbic path?
regulation emotions, reward, cognition
What is function of tuberoinfundibular path?
- inhibit prolactin secretion from pituitary
What type of drugs are D2 receptor antagonists?
antipsychotics
What type of drugs promote dopamine by inhibiting uptake or stimulating release?
- psychostimulants –> cocaine, meth
What are two paths for parkinsons drug treatment?
- give L-DOPA
- D2 agonists
What are the two major types of dopamine receptors?
- both GPCRS
D1: coupled to Gs
D2: coupled to Gi, autoreceptor, target of parkinsons, antipsychotics
Where is norepinephrine synthesized?
locus ceruleas in pons
What is important about locus ceruleas?
- in pons
- site of norepinephrine synthesis
What are the 3 types of NE receptors?
- all GPCRS
B: coupled to Gs
a1: coupled to Gq
a2: coupled to Gi, autoreceptor
What is function of NE in brain?
- vigilance and attention
- central control over SNS
- regulate stress response + emotion
What are 2 actions of antidepressant drugs on NE transmission?
- inhibit NE reuptake
- inhibit MAO [degradation]
Where is serotonin synthesized?
- raphe nucleus in pons/medulla/midbrain [most important is dorsal raphe in midbrain]
What are the 4 types of 5HT receptors we talked about?
5HT1: coupled to Gi, autoreceptors
5HT2: coupled to Gq
5HT3: ligand-gated
5HT4-7: coupled to Gs
Which 5HT receptor is auto?
5HT1
Which NE receptor is auto?
a2
Which dopamine receptor is auto?
D2
Which glutamate receptor is auto?
mGluR1-8 [GPCR]
Which GABA receptor is auto?
GABA-B
What 2 types of drugs affect 5HT2A receptors?
antipsychotics block 5HT2A
hallucinogens are 5HT2A agonists
What drugs affect 5HT1D?
antimigraine drugs are agonists
Where is acetylcholine synthesized?
- brainstem nuclei [dorsolateral tegmuntum] in ponds
- basal forebrain nuclei [nuclei of meynert, septal nuclei]
Where do ACh brainstem nuclei project? function?
- project widely
- important for sleep
Where do ACh basal forebrain nuclei project?? function?
- project to hippocampus
- important for cognition
What is function of ACh in brain?
- cognition
- regulate sleep-wake cycles
- modulate striatal motor function
plus NMJ nicotinic receptors
What are the two types of ACh receptors?
nicotinic: ionotropic
muscarninic: metabotropic, autoreceptor
Which ACh receptor is auto?
muscarinic
Where is histamine synthesized?
tuberomammilary nucleus in hypothalamus
What are the 3 types of histamine receptors?
H1: metabotropic, major in brain
H2: metabotropic, inhibits stomach acid
H3: autoreceptor in brain
Which histamine receptor is auto?
H3
Where is orexin synthesized?
in lateral hypothalamus
Where do orexinergic neurons project?
- tuberomammilary nucleus in hypo [site of histamine synthesis]
- brainstem nuclei [sites of ACh/MOA synthesis]
difference myasthenia gravis vs lambert eaton?
myasthenia: auto against postsynaptic nicotinic receptor, worse with muscle use, treat with ACHesterase inhibitor
lambert: auto against presynaptic Ca channels at NMJ, improves with muscle use
Does bigger or smaller diameter axon have faster conduction?
bigger
dandy walker?
hypoplasia of cerebellar vermis, cystic 4th ventricle, lsuchka/magendie don’t open, congenital hydrocephalus
associated wtih vit a toxicity
chiari 2?
- obstructive
- medulla and cerebellar tonsils herniate down
associated with meningiomyelocele
anencephaly vs encephalocele vs meningomyelocele?
anencephaly: complete failure anterior closure, absence brain formation, brainstem functions ok, before day 24
encephalocele: restricted failure anterior closure, mengingeal +/- cortical tissue herniate past bony opening
meningomyelocele: restricted fialure posterior, due to malnutrition, fetal alcohol, DM, can have chiari II, hydrocephalus, paralysis
