Neuro Block 1 Flashcards
myelinating oligodendrocytes
in white matter
myelinate CNS axons
satellite oligodendrocytes
gray metter next to soma
regulate ECF
recruited ot migrate to axons
astrocytes
form blood brain barrier
interdigitate form glia limitans on CNS surface
form scar after brain injury
composition of blood brain barrier
endothelial cells of blood vesselss
astrocytes
if either of these breakdown you get neuroinflammation and neurodegeneration
astrocytes glia limitans
superficialis - around arteries, penetrating arteries, arterioles
perivascularis - around capillaries
parenchymal microglia
slowly replenished by circulating monocytes from bone marrow
gray and white matter and migratory
when activated can become phagocytic to consume damaged tissue (primary magrophage response)
blood borne monocytes
in perivascular space/choroid plexus
major antigen presenting cell of CNS
secondary macrophage response
ependymal cells
ciliated columnar cells lining ventricals and spinal canal
seperate CSF from CNS
continuous with and give rise to choroid plexus
choroid epithelial cells have tight junctions to create blood CSF barrier
corpus callosum parts
rostrum, genu, body, splenium
diencephalon
anterior commissure
lamina terminalis
optic chiasm
hypothalamus
mammillary bodies
thalamus
midbrain
tegmentum with cerebral peduncles
tectum colliculi
lateral ventricle parts
anterior horn (frontal lobe)
body (frontal/parietal lobe)
posterior horn (occipital lobe)
trigone (btwn temporal, occipital, parietal lobe)
inferior horn (temporal lobe)
flow of CSF
made in choroid plexus (atrium of lateral ventricles)
flow through interventricular foramina to third ventricle
flow through cerebral aqueduct to fourth ventricle
flow through lateral and median aperture to subarachnoid space
CSF flows through arachnoid granulations to superior sagital sinus
subarachnoid cisterns
lamina terminalis
chiasmatic
interpeduncular (infront of midbrain)
prepontine (infront of pons)
ambient (over midbrain)
superior (quadrageminal) - between midbrain, cerebellum, corpus callosum
cerebellopontine (on pons)
lateral cerebellomedullary (on medulla)
dorsal cerebellomedullary (behind medulla below cerebellum)
brocas area (44, 45)
motor function of speech (frontal lobe)
wernickes ares (22)
understanding speech (temporal lobe)
cingulate gyrus
controls emotion
primary auditory cortex
temporal lobe
area 41
primary visual cortex
occipital lobe
area 17
primary somatosensory cortex
area 1,2,3
primary motor cortex
area 4
global apahasia
nt fluent, no comprehension, no repetition
transcortical (pericentral) aphasia
motor - like brocas but can repeat
sensory - like wernickes but can repeat
mixed - like global but can repeat
conduction aphasia
everything normal but cant repeat (arcuate fasiculus)
brain flexures
cervical
midbrain (cephalic)
pontine
telencephalic
cerebellar development
cerebellar plate (part of rhombic lip)
form flocculonodular lobe and posterolateral fissure first
then posterior lobe and primary fissure
then anterior lobe
eye development
from diencephalon
optic vesicle with lens placode
form optic cup (retina) and optic stalk (optic nerve)
pituitary development
from stomodeum in diencephalon
2 parts - neurohypophyseal diverticulum and hypophyseal diverticulum
neurophypophyseal diverticulum to infundibulum to posterior lobe
hypophyseal diverticulum to for ming stalk, rotate and join pars intermedia to form anterior pituitary
neurulation
ventricular zone with germinal cells, intermediate zone with differentiating cells, marginal zone with axons
mitosis happens in ventricular layer
ependymal cells stay in ventricular layer
glioblasts and neurons go to mantle layer
marginal layer is pia layer
INTERMEDIATE ZONE
anterior - basal plate (motor)
posterior - alar plate (sensory)
intermediate zone differentiation
sulcus limitans between each plate
near the sulcus limitans is visceral nerves
alar plate makes general somatic and general visceral afferent
basal plate makes general somatic and general visceral efferent
brainstem they more to have efferents medial and afferents lateral
cerebellar cortical development
cells from alar plate
cells move from ventricular zone to marginal zone on radial glia
start on bottom with intermediate germinal layer go up to form external germinal layer, drop off purkinje cells, go down dropping of granule cells
thalamic development
cells from alar plate
form outside in on radial glia cells
cerebral cortex development
form outside in on radial glia
thalamic nuclei
anterior - attachment/memory
VPL - very painful limbs
VPM - very painful mouth
hypothalamus nuclei
supraoptic - sensing osmotic
anterior - anterior cooling
suprachiasmatic - super clock
mammillary bodies - memory map
upper motor neurons
cell body in cerebral cortec
axon through cerebrum, brainstm, spinal cord
lesions - weakness, increased refled, increased tone
lower motor neurons
cell body in anterior horn
axons become part of peripheral nerve
lesion - weakness, atrophy, fasiculations, decreased reflex, decreased tone
motor neuron tract
primary motor cortex
posterior limb of internal capsule (face posterior, leg anterior)
midbrain basis pedunculi (leg posterior, face anterior)
pons anteriorly in corticospinal tract
medullary pyramids LCST (limbs) decussates, ACST (trunk) doesnt
spinal cord synapse in anterior horn and travel in lateral corticospinal tract (arm medial, leg lateral)
red neuron change
acute ischemia
cytoplasm acidic, loss of nissl staining
eventually neuron engulfed by macrophages
inclusions
accumulation and structural alteration of proteins
parkinsons - lewy bodies
alzheimers - neurofibrillary tangles
rabies - negri bodies
axon injury
wallerian degeneration - degeneration of axon distal to injury
chromatolysis - injury to proximal proteion can result in regenerative efforts, enlargement and rounding of cell body with peripheral displacement of nucleaus, dispersion of nissl substance
astrocytes response to injury
gliosis/astrocytosis - scarlike tissue in brain
oligodendroglia response to injury
loss of myelin/decreased myelin production
ependymal granulations
subpial astrocytes underneath ependymal layer around ventricles proliferate with severe hydropcephalus
microglia with infection
elongate and aggregate
anencephaly
anterior end
lack of cerebral hemispheres
folic acid deficiency
spina bifida
occulta - no herniation
meningocele - herniation of meninges
meningomyelocele - herniation meninges and nervous tissue
encephalocele
herniation of brain through skul
cystic disorders
syringomyelia - clefts in spinal cord or brainstem
hydromyelia - enlargement of central canal
holoprosencephaly
single cerebral hemisphere and ventricles (trisomy 13 and 18)
arnold chiari
type 1 - herniation of cerebellar tonsils
type 2 - small posterior fossa, herniation cerebellar vermis, elongation of brainstem through foramen magnum, hydrocephalus, 95% with meningomyeloceles
dandy walker
agenesis of cerebellar vermis
posterior fossa enlarged
hydrocephalus
neuronal heterotopia
neurons dont migrate correctly and end up in abnormal locations
polymicroglia
too many gyri, too small
lissencephaly
absent gyri
micrencephaly
brain (head) is too small
megalencephaly
brain too large
agenesis of corpus collosum
can be normal or with retardation
perinatal anoxic ischemic lesions
infart like - ulegyria (white matter - periventricular), laukomalacia (grey and white matter - multicystic encephalopathy), basal ganglia (status marmoratus - myelination), entire hemisphere (hydranencephaly)
hemorrhagic - germinal matric (prematurity, often extends into ventricle)
perinatal metablic lesion
kernicterus - bilirubin can injur newborns due to incomplete blod brain barrier
cholinergic drugs (pro parasympathetic)
muscarinic agonists - acetylcholine, bethanechol, carbachol, methacholine, pilocarpine, muscarine, nicotine, succinylcholine, varenicline, cevimeline
reversible cholinesterase inhibitors - edrophonium, physostigmine, pyridostigmine, neostigmine, donepezil, rivastigmine
irreversible cholinesterase inhibitors - organophosphates, para/mala(thion), echothiophate, nerve agents, sarin, vx
parasympathetic receptors
agaonistic - M1,3 (heart, lungs, GI, bladder, glands, blood vessels)
antagonistic - M2 (heart)
anticholinergic drugs (anti parasympathetic)
cholinesterase reactivators - pralidoxime
muscarinic antagonists - atropine, hyoscyamine, scopolamine, oxybutynin, tropicamide, dicyclomine, benztropine, pirenzopine, tolterodine, glycopyrrolate, ipratropium, tiotropium
ganglionic blocking drugs - rocuronium, vecuronium, pancuronium, mivacurium, tubocurarine, mecamylamine, trimethaphan, hexamethonium
ACh synthesis inhibitors - hemicholinium, vesamicol, botulinum toxin
sympathetic receptors
alpha 1 - smooth muscle contraction, pupil dilation, BP increase (NE>Epi)
alpha 2 - inhibitory effects (Epi=NE)
beta 1 - cardiac HR increase (Epi>NE)
beta 2 - bronchodilation, BP decrease (Epi>NE)
sympathetic agonists
beta agonists - epinephrine, norepinephrine, dopamine, albuterol, salmeterol
alpha agonists - 1 (phenylephrine, midodrine) 2 (clonidine, guanafacine, alphamethyldope, tizanidine)
sympathomimetics - amphetimine, cocaine, ephedrine, tyramine
sympathetic antagonists
alpha blockers - phenoxybenzamine, phentolamine, prazosin, doxazosin, terazosin, tamsulosin
beta blockers - (Nonselevtive - propranolol, nadolol, timolol) (selective - metoprolol, atenolol, betaxolol, esmolol)
alpha beta blockers - labetalol, carvedilol
tyrosine hydroxylase inhibitor - metyrosine
osins alpha 1
catecholamines
epinephrine, norepinephrine, dopamine
tyrosine to dopa with tyrosine hydroxylase (w BH4)
dopa to dopamine (decarboxylated)
oxidized to norepinephrine (uses Cu)
methylated to epinephrine
degraded by monamine oxidase and catechol o methyl transferase - produces metanephrines and vanillymandelic acid
NT in vesicles
transported via VMAT2, exchanged for hydrogen
serotonin
tryptophan hydroxylated (using BH4)
dopa decarboxylase converts to serotonin
degraded by MAO and oxidation or acetylated and methylated to melatonin
histamine
histidine decarboxylase
degradation depends on tissue
brain methylates then MAO-B deaminate, oxidized to final product
peripheral tissues diamine oxidase followed by oxidation
acetylcholine
acetyl coa and choline (requires SAM)
degredation by acetylcholinesterase
glutamate and GABA
transamination of alpha ketoglutarate to glutaminase and glutamate dehydrogenase to glutamate
decarboxylated to GABA
GABA shunt runs through TCA to alpha ketoglutarate back to glutamate
glycine
glycine made from serine by serine hydroxymethyl transferase, PLP, and folate
serine made from 3 - phosphoglycerate from glycolysis
receptors
biogenic amines - all but 1 are GPCR
acetylcholine - muscarinic are GPCR, nicotinic are ion channels
glutamate - ionotropic (AMPA, NMDA) and metabotropic (group 1 post synaptic, group 2/3 presynaptic)`
GABA - ionotiopic A/C, B is metabotropic
glycine - ionotropic
purine receptors
P2X ion (neurons) , P1 and P2Y (neurons and strocytes) GPCR
enkephalins
synthesis increased in painful stress
hyperpolarize presynaptic membrane inhibiting transmission of pain signals
endorphins
bind receptors and hyperpolarize, inhibiting the release of substance P
motor nuclei
oculomotor - CN III
trochlear - CN IV
abducens - CN VI
hypoglossal - CN XII
motor nucleus of CN V
facial nucleus - CN VII
nucleus ambiguous - CN IX and X
accessory spinal nucleus - CN XI
edinger wetphal - CN III
superior salvitory nucleus - CN VII
inferior salvitory nucleis - CN IX
dorsal motor nucleus of CN X
sensory nuclei
nucleus solitarius (rostral) - CN VII, IX, X
nucleus solitarius (caudal) - CN IX and X
trigeminal nuclei - CN V, VII, IX, and X
cochlear nuclei - CN VIII
vestibular nuclei - CN VIII
midbrain nuclei
rostral - oculomotor, edinger westphal (CN III) and mesencephalic tract (CN V)
caudal - trochlear nucleus (CN IV) and mesenchephalic tract (CN V)
pons nuclei
rostral - trigeminal motor (CN V), principal sensory nucleus (CN V)
caudal - abducens nuc (CN VI), superior salvitory nucleus (CN VII), facial motor nuc (CN VII), solitary nuc (taste), vestibular nuc (CN VIII balance), spinal trigeminal nuc (CN V)
medulla nuclei
rostral - inferior salvitory nucleus (CN IX), nucleus ambiguous (CN IX and X), solitary nucleus (taste), cochlear nucleus (hearing)
both - vestibular nucleus (balance, spinal trigeminal nuc (CN V)
caudal - hypoglossal nuc (CN XII), dorsal motor nucleus of vagus (CN X), solitary nucleus (cardiorespiratory)
corticonuclear tract
upper face - collateral branches on ipsilateral side
lowerface - only contralateral innervation
nucleus in pons
UMN lesion - lower face paralysis on contralateral side
LMN lesion - full face weakness on ipsilateral side
lesions to nucleus ambiguous
uvula points to strong side
in medulla
UMN - point to side of lesion
LMN - point to opposite side of lesion
lesions to hypoglossal nucleus
tongue deviates to weak side
in medulla
UMN - point to opposite side of lesion
LMN - point to side of lesion
multiple sclerosis
appears to be autoimmune
CD 4 T cells initiate disease
lesions (plaques) common in white matter near ventricles - active (macrophages) and chronic (loss of myelin)
symptoms - secondary to loss of myelin, often start as optic neuritis
CSF - oligoclonal bands with immunoelectrophoresis (B cells)
treat with immunomodulators (DMT then fumarates then teriflunomide)
relapsin remitting
primary progressive
progressive relapsing
secondary progressive
acute disseminated encephalomyelitis
follows viral infection or immunization
monophasic
general symptoms (headache, lethargy, fatigue)
acute hemorrhagic encephalomyelitis
follows upper respiratory illness
fatal in many
periventricular demyelination
hyperacute
neuromyelitis optica (devic disease)
bilateral optic neuritis and spinal cord lesions
central pontine myelinolysis
loss of myelin in pons
rapid correction of hyponatremia in alcoholics
B12 deficiency
subacute combined degeneration of spinal cord
vacuolization
ataxia, numbness, tingling
thiamine deficiency
wernicke korsakoff - necrosis of mammillary bodies and other midline structures
alcohol related
hepatic encephalopathy - hepatic cirrhosis leads to alzheimers type 2
alcohol cerebellar degeneration
disturbances in conciousness, fluctuating neurological signs including rigidity, hyperreflexia
carbon monoxide
necrosis of globus pallidus, hypoxic changes, cherry pink skin
subacute sclerosing panencephalitis measles
demyelination/gliosis
progressive multifocal leukoencephalopathy
JC virus in immunocompromised
multiple areas of demyelination
abnormal astrogliosis
methanol
degeneration retinal ganglion cells (eyes)
ethanol
degeneration of anterior superior cerebellar vermis
methotrexate
necrosis around ventricles or vessels
krabbe disease
sphingolipidosis
deficiency of galactocerebroside beta galactosidase
stiffness and weakness, worsening problems with feedings
metachromatic leukodystrophy
deficiency o arylsulfatase A which cleaves sulfat containing lipids
accumulation fo sulfatides
myelin breakdown
bone marrow transplant
adrenoleukodystrophy
X linked
VLCFAs accumulate
myelin loss in deep white matter
Foster Kennedy Syndrome
tumor in olfactory groove
ipsilateral insomnia, ipsilateral optic aatrophy, contralateral papilledema
meningioma
cerebellopontine angle syndrome
schwannoma
ipsilateral facial pain and sensory loss, facial nerve palsy, tinnitus, hearing loss, dizziness, unsteadyness
CN V, VI, VII, VIII)
cavernous sinus syndrome
pain and sensory disturbances in V1/2 distribution
ipsilateral ophthalmoplegia
jugular foramen syndrome
vernets syndrome
loss of taste to posterior 2/3 of tongue (IX)
paralysis vocal cords and palate, anesthesia of larynx and pharynx (X)
ipsilateral trap and SCM weakness (XI)
pancoast tumor
apical lung lesion
invovle brachial plexus and sympathetic trunk/path
hypoglossal nerve
tongue muscles (except palatoglossus)
UMN - contralaterral tongue weakness
LMN - ipsilateral tongue weakness
collet siccard syndrome
jugular foramen syndrome with involvement of CN XII
posterior column medial lemniscus path
fine touch, vibration, proprioception
enter dorsal horn and travel in ipsilateral side dorsal column (gracile fasciculus medial, cuneate fasciculus lateral)
synapse in caudal medulla and decussate to travel in medial lemniscus (gracile nucleus anterior, cuneate nucleus posterior)
synapse in thalamus ventroposterolateral nucleus, use posterior limb of internal capsure to somatosensory cortex
spinothalamic tract
pain and temp
enter and synapse in dorsal horn, decussate at this level to anterolateral column (upper cervical medial, sacral lateral) to travel to thalamus
synapse at ventral posterolateran nucleus and take posterior limb of internal capsule to somatosensory cortex
trigeminal nerve nuclei
main sensory nucleus - fine touch, dental pressure
-trigeminal nerve axons in trigeminal ganglia enter at lateral edge of pons and synapse on principal sensory nucleus, form posterior trigeminothalamic tract, synapse in VPM and travel through internal capsule to postcentral gyrus
spinal nucleus - crude touch, pain, temperature
-trigeminal nerves enter at pons and descend in spinal trigeminal tract, terminates on spinal trigeminal nucleus, travel up in anterior trigeminothalamic tract, terminate in VPM then internal capsule to postcentral gyrus
mesencephalic nuclus - proprioception
-muscle spindles in masseter muscle detect stretch (pseudounipolar neurons with soma in mesencephalic nucleus) these neurons synapse on motor nucleus of V
central cord lesion
anterior spinal artery
bilateral paresis or paralysis of upper limb
loss or psin and temp below lesion
sphincter dysfunction
medial medullary syndrome
anterior spinal artery
contralateral hemiplegia of upper and lower limbs and trunk
contralateral loss of tough and vibration
deviation of tongue to ipilateral side
posterior spinal artery syndrome
ipsilateral loss of fine touch and vibration below
lateral medullary syndrome
PICA lesion
contralateral loss of pain and temp
ipsilateral loss of pain and temp in head
dysphagia, hoarseness, diminished gag reflex
ipsilateral Horner syndrome
ataxia to ipsilateral side
medial pontine syndrome
paramedian basilar artery
contralateral hemiplegia
contralateral loss of fine touch and vibration
caudal lesion - ipsilateral lateral rectus muscle paralysis, ipsilateral fascial muscle paralysis
lateral pontine syndrome
lond circumferential basilar artery (AICA)
ataxia toward side of lesion
vertigo, nausea, deafness
ipsilateral facial paralysis
ipsilateral Horners
ipsilater pain and temp of face
contralteral pain and temp of body`
medial midbrain (Weber)
paramedian basilar bifurcation
contralateral hemiplegia
ipsilateral paralysis of oculomotor nerve, dilated pupil, ptosis
central midbrain (Claude)
paramedian basilar bifurcation
contralateral ataxia and intention tremor
ipsilateral paralysis of oculomotor nerve, dilated pupil, ptosis
vestibuocerebellar module
afferent - vestibular nerve to vestibular nucleus and cerebellar vermis, vestibular nucleus to cerebellar vermis via mossy fibers
efferent - cerebellar vermis to fastigial nucleus and vestibular nucleus, vestibular nucleus down spinal cord in vestibulospinal tract (extensor muscles), fastigial nucleus to reticular nuclei and down spinal cord in reticulospinal tract (possture and muscle tone)
spinocerebellar module
afferent - lower limb and trunk proprioceptor neurons synapse and travel up spinal cord in dorsal spinocerebellar tract to restiform body to cerebellar cortex via mossy fibers // upper limb proprioceptor neurons travel up cuneocerebellar tract and synapse in accesory cuneate nucleus and continue up to restiform body to cerebellar cortex via mossy fibers //intermediate zone and spinal border cells decussate and travel up spinal cord in ventral spinocerebellar tract to superior cerebellar peduncle to cerebellar cortex via mossy fibers // posterior thoracic nucleus of Clarke go up some and decussate and continue to cerbral cortex
efferent - vermal cortex sends neurons to fastigial nucleus which send neurons to ventrolateral nuclues of thalamus to trunk area of motor cortex AND fastigial nucleus sends neurons to reticular nuclei and vestibular nucleus and fastigiospinal fibers to anterior horn // intermediate cortex sends neurons to interposed nuclei which send neurons to the ventrolateral nucleus of thalamus to trunk and limb areas of motor cortex AND interposed nucleus sends fibers to red nucleus then to anterior horn
pontocerebellar module
afferent - corticopontine fibers synapse on pontine nucleus and send fibers to dentate nucleus and lateral cortex via mossy fibers, red nucleus sends signals to inferior olivary nucleus to inferior cerebral peduncle to dentate nuclei and to lateral cortex via climbing fibers
efferent - lateral cortex sends fibers to dentate nucleus which goes through decussation of sup cerebellar peduncles to the inferior olivary nucleus, red nucleus, pontine nuclei, and ventrolateral nucleus of thalamus to cerebral cortex
