Neuro Flashcards
primary motor area location
precentral gyrun
broca speech area location
inferior frontal gyrus (frontal lobe) in dominant hemisphere
location of supplementary motor cortex
superior frontal gyrus
primary somatosensory area of cerebral cortex
post central gyrus
association areas involved in somatosensory functions
superior parietal lobule
two components of inferior parietal lobule
supramarginal gyrus
angular gyrus
purpose of supramarginal and angular gyri
supramarginal - interrelates somatosensory, auditory, and visula inputs
angular - receives impulses from visual cortex
location of Wernicke speech area
superior temporal gyrus (in temporal lobe. remember Broca is in inferior frontal gyrus of frontal lobe) in dominant hemisphere
two structures that house the visual cortex
cuneus and lingual gyrus in occipital lobe
components of striatum
cuadate nucleus
putamen
components of lentiform nucleus
putamen
globus pallidus
location of choroid plexus
lateral ventricles
dvlp pathway cerebral hemispheres
forebrain, telencephalon WALL
dvlp pathway lower part of 4th ventricle
hindbrain, myelencephalon CAVITY
dvlp pathway pons and cerrebellum
hindbrian, myelencephalon WALL
dvlp pathway thalamus, hypothalamus
forebrain, diencephalon WALL
dvlp pathway aqueduct
midbrain, mesencephalon CAVITY
dvlp pathway midbrain
midbrain, mesencephalon WALL
dvlp pathway upper fourth ventricle
hindbrain, metencephalon CAVITY
dvlp pathway medulla
hindbrain, myelencephalon WALL
origin CNS neurons
neural tube
origin microglia
blood borne macrophages…mesoderm
origin schwann cells
neural crest
origin oligodendrocytes
neural tube
origin astrocytes
neural tube
origin PNS neurons
neural crest
origin ependymal cells (inner ventricle lining(
neural tube
origin pigment cells (melanocytes)
neural crest
origin parafollicular cells (calcitonin C cells)
neural crest
what two conditions increase risk neural tube defects
maternal diabetes and low folic acid intake (PRIOR TO CONCEPTION AN DDURING PREGNANCY)
all neural tube defects will have increased AFP except
spina bifida (nml)
what neurotrnasmitter in amniotic fluid is helpful in confirming neural tube defect in addition to AFP
AchE
MOA anencephaly
failure of ROSTRAL neuropore to close
presentation of anenecephaly
no forebrain, open calvarium, poly =hyramnios
MOA spina bifida occulta
failure of CAUDAL neuropore to close, but no herniation
presentation of spina bifida occulta
usually seen lower vertebral level, assocaited with intact tdura and tuft of hair/dimple at bony defect
meninges herniate through bony defect (no neural tissue)
meningocele
spina bifida cystica
meningocele
meniningesAND neural tissue (cauda equina( herniate through bony defect
meneingmyelocele
GA when neuropores fuse
4th week
neural tube defects usually occur here (persistent connection between amniotic fluid and spinal canal)
MOA holoprosencephaly and timing
failure of left and right hemispheres to separate at week 5-6
biochemical pathway involved in holopros
sonic hedgehog
holoprosencephaly assssociated with what syndromes
patau (trisomy 13) and fetal alcohol syndrome
MRI presentaiton of holoprosencephaly
monoventricle (one huge ventricle) and fusion of basal ganglia
which chiari malformation is least severe and why
chiari 1 (usually asymptomatic in childhood and manifests in adult hood with headaches and cerebellar symptoms) this is due to ectopia of only the cerebellar tonsils (1 structure)
which chiari malformaiton is assocateid with hydrocephaus, and lumbosacral meningomyelocele
chiari 2
what herniates in chiari 2
low lying cerebellar vermis and tonsils
cystic enlargement of fourth ventricle due to AGENESIS of cerebrellar vermis
dandy walker
what gets enlarged in dandy walker
4th ventricle and posterior fossa
what two diseases are dandy walker associtedd with
spina bifida and noncommunicating hydrocephalus
which spinal cord defect is associated with chiari malformaitons
syringomyelia (cystic cavity wihtin central canal of spinal cord)
“cape like” bilateral loss of pain and temperature sensation in upper exremities (fine touch sensation prserved)
syringomyelia (cystic cavity within centrla canal of psinal cod that damages fibers corssing anterior white commisure- spinothalamic tract) FIRST
MCC site syringomyelia
C8-T1
“frog like aappearance of fetus”
anencephaly
taste nerves
7 9 10 (solitary nucleus)
tongue pain nerves
v3 ix x
motor tongue nerve
x and 12
origin of anterior 2/3rds tongue
1st and 2nd branchiwal arches (cn 5 and 7(
posterior 1/3rd tongue
arches 3 and 4 (sensation and taste 9, posterior sensory X)
which nerve retracts, depresses tongue, draws sides of tongue upward, protrudes tongue
cn 12
which nerve elevated posterior tongue during swalling
10
components of neurons and functions
dendrites receive input
cell bodies
axons send output
Wallerian degeneration
degeneartion of axon distal to site of injury and axonal retraction proximally
potential regeneration of what cells if wallerian degeneration?
PNS cells
astrocyte marker
GFAP
purpose of astrocytes
physical support, repair, removal excess NTs, form component of blood brain barrier,
SUPPORT CELL
what are the scavenger cells of hte CNS (phhagocytes)
microglia (actiavted in response to tissue damage)
origin of microglia
since they are macrophages they are MESODERM
what undergoes reactive gliosis in response to neural injury
astrocytes
origin of astrocytes
neurocectoderm
what helps buffer K concentration in extracellular space
astrocytes
biochemical markers for astrocytes
gltuamine synthetase and GFAP
which cells line luminal surface of choroid plexus and produce CSF
epndymal cells
myelin forming cells of PNS and CNS
pns - schwann cells
cns - oligodendrocytes
BBB consists of
tight junctions of nonfenestrated endothelial cells and ASTROCYTIC FOOT PROCESSES and BASEMENT MEMBRANE
how does infarction o fbrain tissue affect BBB
destroys tight junctions and results in vasogenic edema (plasma) into extracellular space
where is neuromelanin found
substnatia nigra and locus ceruleus (disappears in Parkinson)
lipofuscin (aging accumulation) are derived form what organelle
lysosomes
lewy bodies…what dx
neuronal inclusions characterisitc of parkinsons
negri bodies
intracytoplasmic inclusions pathgnoinc for raibes!!!!
found in pyramidal ells of hippocampus and purkinje cells of cerebellum
intraneuronal, eosinophilic rodlike inclusions found in hippocampus
alzheimers (Hirano bodies)
cowdry type a inclusion bodies
HSV
how many axons can one schwann cell myelinate
1 pns axon
how many axons can one oligoendrocyte myelnate
many CNS axons about 30
predominant in white matter
what cell type is injured in guillan barre
schwann cells
what cell type is injured in MS, progressive multifocal leukoencephalopathy PML and leukodystrophies
oligodendrocytes
where are free nerves located and what do they mediate
located on all skin and epidermins…some viscera
pain and temperature
large myelinated fibers found in depe skin layers that sense vibration and pressure
pacinian corpusccles
dep static touch and position sense found in finger tips
merkel discs
dendritic endings with CAPSULE found in finger tips sense pressure and slippage of objects along skin
ruffini corpuscles
found on hairless skin sense dynamic, fine/light touch and position sense
meissner corpuscles
inflammatory infiltrate in guillan bare syndrome
endoneurium
layers of peripiheral nerve
endoneurium surrounding one nerve fiber-> perineurium (blood nerve permeability -barier that surrounds fasicle of multiple nerve fibers) -> epineurium surrounding entire nervee of fascilcles and blood vessels)
reaction of neuronal cell body to axonal injury concurrent with Wallerian degeneration
chromatolysis
3 characteristics of chromatolysis
round cellular swelling
displacement of nucleus to periphery
dispersion of nissl substance throughout cytoplasm
where is Ach synthesized
basal nucleus of meynert
where is GABA made
nucleus accumbens
where is norepi made
locus ceruleus
where is serotonin made
raphe nucleus
where is dopamine made
ventral tegmentum and SNc
which two meningeal layers are derived form neural crest
the two inner ones (arachnoid and pia mater)
origin of dura mater
mesoderm
how o glucose and AAs corss BBB vs nonpolar lipid soluble substances
glucose and AAs - slow via carrier mediated transport
nonpolar lipids - rapid via diffusion
what specialized brain regions have no BBB to allow molecules to pass to alter brain function
OVLT organum vasculosum lmaina terminalis for osmotic sensing, neurohypophsis for neurosecretory products of area psotrea *vomiting after chemo”, responds to emetics
what does hypothalamus regulate
TAN HATS thirst and water balance adenohypophiss (anterior pit) neurohypophis (posterior pit) hunger autonomic nervous system temperature seual urges
inputs to hypothalamus (areas not protected by BB)
OVLT - osmolarity changes
area postrema - medulla, responds to emetics
lateral area of hypothalamus
hunger
destruction = anarexia, fialure to thrive
stimulated by ghrelin, inhibited by leptin (do not LEPT me eat)
zap lateral area you shrink laterally
venteromedial area of hypothalamus
satiety
destruction = hyperphagia…
stimulated by leptin
zap this and you grow ventrally and medailly
anterior hypothalamus
cooling, parasympathetic
A/C air conditioning, anterior cooling
posterior hypothalamus
heating, sympathetic
zap this and you become cold (poilikotherm)
suprachiasmatic nucles
circadian rhythm
sleep to be charismatic
supraoptic and parventricular nuclei
synthesize ADH and oxytocin
carried by neurophysins down axons where these hormones are stored and released
circadian rhythm controls nocturnal release of what NTs
ACTH, prolactin, melatonin and norepi
how is melatonin released
SCN (suprachiasmatic nucleus) -> norepi release -> pineal gland -> melatonin
what substances decreased REM and delta wave sleep
alcohol, barbituates, benzos and norepi
treatment for bedwetting
oral desmopressin (ADH analog)
but always try motivational therapy first
what to use for nigh terrors and sleepwalking
benzos (decrease N3 and REM sleep)
stages of sleep
awake open eyes, awake eyes closed, nonREM stage N1, n2, n3, REM sleep
what waves are assocaited with each stage
BATS Drink Blood
beta (highest frequency lowest amplitude)
alpha
theta
sleep spindles, K complexes
delta (loweest frequency, highest amplitude)
beta (REM sleep)
what happens to motor tone durign REM
loss of motor tone
what happens to brain O2 use, variable pulse, BP, and Ach during dreamig
all increase
how often does REM happen
every 90 mins
function of thalamus
major relay for all ascending SENSORY info except olfaction
ventral posterolateral nucleus
relay Vibration Pain Pressure Proprioception Light touch, temp from spinothalmuc, dorsal columns to primary somatosensory cortex
Ventral posterooMedial nucleu
face sensation and taste “make up goes to the face”
Lateral geniculate nuclues
relays CN II visual informaiton to calcarine sulcus (lateral to light)
medial geniculate nucleus
input form superior olive and inferior colliculus of tectum to relay AUDIO info to adutiory cortex of temporary lobe (lmedial = music)
ventral lateral nucleus
relays motor info from basal ganglia to motor cortex
5 Fs of limbic system
feeding fleeing fighting feeling FUCKING
4 dopaminergic pathway abnormaliteis
mesocortical, mesolimbic, nigrostriatal, tuberonfundibular
mesocortical pathway abnormalities
decread activity leads to “negative symptoms”
mesolibic abnormalities
incresaed activity leads to “positive symptoms” (target for antipsychotics)
nigrostriatl abnormalities
decreae activity leads to EPS (dystonia, akathisa, parkinsonism, tardive dyskinesai) MAJOR DOPAMINERGIC PATHWAY IN BRAIN
tueroinfundibular abnormality
decreasd activity leads to increaed prolactin and decreased libido…sexual dysfunction galactorrhea gynecomastia
which dopaminergic pathway is significantly affectedby movement disorders and antipsychotic drugs
nigrostriatal
