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USMLE facts 6

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ang93's version from 2017-05-01 14:55

NMBE

Question Answer
acute painless monocular vision losscentral retinal artery occlusion - often permanent
CRAO signs on fundoscopycherry red macula (fovea and foveola have a separte blood supply fro choroid artery), pale retina (ischemia and edema)
amaurosis fugaxpainless transient monocular LOV due to small embolus to opthalmic artery
blurry vision, black spots, floaters, and dec peripheral visiondiabetic retinnopathy
young obese women, daily headache, bilat sym papiledema, transient visual disturbances, sx worsen during valsalvapseudotumor cerebri (idopath intacranial HTN) - impaired cerebral venous outlow - build up of pressure compressed the optic nerves externally - impair axoplasmic flow wi optic nerves - bilateral optic disc edema (papilledema)
uveal tractiris (ant), ciliary body (ant) choroid (posterior)
uveitisautoimmune,CMV, syphyllis, tuberculosis
painful monocular vision loss, headache, vomiting, conjunctival injection, poorly reactive mid dilated pupilacute angle closure glaucoma
progressive painless, bilateral loss of vision w optic disc cuppingopen angle glaucoma
monocular LOV over several weeks w painful eye movmtsoptic neuritis
gradual LOV in one or both eyes, difficulty with driving or readingDRY AMD
leading cause of blindness in industrialized countriesAMD
predipose to AMDsmoking and advanced age
chronic oxidative damage to retinal pigment epith & choriocapillaris -> subretinal inflam w abnl matrix formn -> drusen spotsDRY AMD
progressive ECM accum -> retinal hypoxia -> stim local VEGF -> SUBretinal neovasc'n w formation of leaky vesselsWET AMD - acute vision loss w metamorphopsia (disortion of straight lines)
drusen spotsDRY AMD
metamorphopsia, fundoscopy grayish green subretinal discoloration and adj fluid/hemorrhageWET AMD - distortion of straight lines
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Histology

Question Answer
PAS stains for ___glycoproteins; highlights polysaccs, mucosal substances, and basement membranes
prussian blueirons stains blue
H&E calciumstains dark purple
sudan black or nile redneutral lipids
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Microbiology

Question Answer
oval encapsulated budding yeastscryptococcus neoformans
pharynx -> lymphatics -> meningh influ meningitis (infants and y child)
middle ear -> contiguous tissue -> meningesunusu mech where s. pneumo can gain access to CNS during ear infxn
wound -> leaking CSF -> meningMC cause of s. aureous meningitis or CNS abscess (neurosurgery)
primary lung focus -> blood -> meningesm. tuberculosis or s. pneumo
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Cardio

Question Answer
hemorrhagic infarctsdual blood supply or reperfusion injury
inferior MIoften due to RCA blockage - reponsible for SA and AV node perfusion - bradycardia w MI - need atropine
atherosclerotic plaque formationfatty streak -> plaque --> atheroma
atherosclerosis particularly affectscoronary, politeall, renal , carotids, and CoW
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Pulm

GI

Question Answer
fatigue, pruritis (usu worse @ night), HSM, cholestasis, xanthelasmaprimary biliary cirrhosis
late manifestations of PBCcirrhosis and PHTN
fatigue, high AP, long hx UC, diffuse inflam/fibrosis of large intra and extra hepatic bile ducts w periductal concentric fibrosis "onion skin" and obstruction of small ductsprimary sclerosing cholangitis
fever, prolonged RU ab pain after fatty meal, middle aged obese womanacute cholecystitis
weight loss, ab discomfort, jaundice, epigastric masspancreatic cancer
senescent ceruloplasmin and unabsorbed Cusecreted into bile and excreted into stool
R sided adenocarcinoma presentationbleed, Fe def anemia (tend to grow large buky masses bc large caliber of ascending colon)
L sided adenocarcinoma presentationobstructing sx - altered bowel habits, constipation, ab distention, n/v (smaller tumors, narrowing the small lumen, more obstruction)
watershed areas of the bowelspenic flexure (btw SMA and IMA) and rectosigmois jxn (sigmoid artery and superior rectal artery)
MC location for intusseptionileocolic jxn! due to size difference (iluem into colon) - sometimes assocd w viral infxn
intusseption presentationcolicky, intermit ab pain, n/v, currant jelly stools, possible palpable tubular mass in LRQ - barium enema dx - need surgery
postprandial epigastric pain w assocd food aversion/weight loss, doesnt respond to antacidschronic mesenteric ischemia (similar to angina pectoris)
acute mesenteric ischemia is most likepulm embolism; SMA embolism - sudden severe ab pain NOT post prandial
portal triadhepatic portal vein, hepatic artery and bile duct
hemochromotosis mutationmissense mutation HFE -> imapired iron sensing by hepatocytes and enterocytes cells -> enterocytes inc apical DMT1 expression and inc absorption & hepatocytes dec HEPCIDIN (inc ferroportin exprson on basolat surface of enterocytes) and promotes iron secretion into circ
serum proteins/hemochromotosisinc ferritin and in transferrin saturation
lesser omentum componenthepatoduodenal ligmt &n hepatogastric ligmt
splenic flexureleft colic flexure
remnant of fetal umbilical veinround ligament
embryonic ventral mesenteryfalciform ligament
wilsonsbg atrophy, liver cirrhosis, hinder copper metab by reducing the formation and secretion of ceruplasmin and dec hepatic secretion Cu into biliary system
kayser fleischer ringsgranular deposition Cu w descemets membrane in the cornea
alpha 1 antitrypsin deficiencypanaccinar emphyseama and liver dz (defective protein gets trapped in the liver - HM or HSM, cholestasis inc transaminases, mild thrombocytopenia) - can get cirrhosis and hepatocellular carcinoma
memorize

 

Question Answer
Dubin Johnsondirect hyperbilirubinemia - excretion defect grossly black liver due to impare epinephrine metab excretion
Gilbertsunconj hyperbili - defect in promoter gene for uridine diphophoglu.-glucuronsyltransferase 1A1 - dec bilirubin uptake, occues w fasting, stess, EtOh intake - rifampin test
Crigler-Najjarunconj hyperbilirubinemia (type 1 > severe than type 2), brain damage in infancy, neonat jaudince, kernicterus (bilirubin depo in brain -deafess, poor mental progression)
unconjugated hyperbilirubinemiahemolytic, physiologic (newborn), Crigler Najjar, Gilbert
conjugated hyperbilirubinemiabiliary tract obstruction: gall stones, cholangiocarcinoma, pancreatic or liver cancer, liver fluke, bilary tract dz (1' sclerosing cholangitis or 1' biliary cholangitis), dubin johnson and rotor
physiologic jaundiceimmature UDP glucuronosyltransferase -> unconj hyperbili -. jaundice/kernicterus
memorize

Renal

Question Answer
palpable flank mass discovered in child while bathingWilms tumor - resembles primitive metanephric tissue
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Neuro

Question Answer
lateral geniculate nucleusvisual
medial geniculate nucleusauditory
ACA occlusionsensory and motor of contralat LEG, if BILATERAL - behavioral sx (abulia) and urinary incontinence (medial frontal lobe and cingulate gyrus)
abuliano will power, indecisive
MCA occlusionmotor hand, face/mouth, throat, brocas (dom), anosognosia and spatial neglect (nondom), conj gaze deviation twd side of stoke, homonymous hemianopsia (optic radiation in subcortical temporoparietal lobe
anosognosiaPOOR INSIGHT - cant recog their disorder
Marcus gunnrelative afferent pupil defect
which portion of the retina contribs the most to input at pretectal nucleusnasal portion
early onset alz genesAPP (ch 21), presenilin 1 and 2
late onset alz genesapoE4
MG and motor end plate potentialdecreased motor end plate potential - dec the amt of fxnal receptors
insulaemotion
posterior limb ICsep lentiform from thalamus - carries CST motor and somatic sensory fibers and visual and aud fibers
genu of ICCBT fibers
ant limb ICsep caudat from lentiform - thalamocortical fibers
xanthochromiablood in CSF, suggestive of SAH in lumbar punture - most sensitive for diagnosis
chiari malformationcongential disorders from underdevelopmt of posterior fossa - small size causes cerebellum to hernitate thru F.M.
Chiari malformation 1MC benign low lying cerebellar tonsils extendn into vert canal, paroxysmal occipital headaches (mening irritation) and cerellar ataxia
Chiari malformation 2Arnold, MORE SEVERE, evident in neonate, cerebellum AND MEDULLA thru F.M. - noncomm hydrocephalus - aqeuductal stenosis - medulla comprssion - dysphagia, stridor, apnea
malformation assocd lumbar myelinomeningocelechiari 2, can cause LL paralysis
petit mal seizuresabsence
sudden momentary laspse in awareness, staring, rhythmically blinking, ocasional small jerk of arm or hands NO POST ICTALabsence
3Hz spike wave complexes superimposed on nL background activityabsence seizures
subfalcine herniationcingulate gyrus herns thru falx cerebri, compressing ACA
uncal herniation leads to...CN3 compression, ipsilat PCA compression - homo hemi w macular sparing, compression contralat cerebral peduncle (contralat CST damage -> ipsilat hemiparesis) or ipsilat cerebral peduncle, brainstem hemorrhages (STRETCH AND RUPTURE BASILAR ARTERY - FATAL)
lateral gray matter hornsthoracic and early lumbar s.c. - interomedial cell columns - pregang sympathetics
where does cuneate fasculi join gracileT7
CSF pathwaylat-monro-3-aqueduct-4-luscka&magendie-subarachnoid space-arachnoid granulation - venous sinus
communicatin hydrocephdysfxn or obliteration of subarach villi - sequelae of meningeal infxns or subarach/intravent hemorrhage - ALL VENT SYM ENLARGED
s.c.injury above ____ can also cause ipsilat HORNERST1 - oculosympathetic pathway
baby subdural hemorrhage, retinal hemorrhage, large head, higher brain water content, dec cervical muscle toneabusive head trauma - vigorously shaking baby
post rib fx babybaby
spinocerebellar degenf ataxia
foot abnls and D.M. loss of p/v sensatoinf ataxia
GAA repeatsf. ataxia
AD, demylenation of PNs, distal leg weakness, atrophy, sensory def, pes cavus, kyphoscoliosis, NO CMCharcot-Marie-Tooth
damage to brainstem at or below the red nucleus (midbain tegmentum, pons)decerebrate (EXTENSOR) posturing - via vestibulospinal tract (loss of rubrospinal excitation)
damage above red nucleusdecorticate (FLEXOR) posturing - via rubrospinal tract (hyperactivity of flexors)
cushing triadHTN, radycardia, resp depression - brainstem compression
oculomotor dysfxn, ataxia, confusionwernickes encephalopathy
oculomotor dysfxn in wernickes encephCN3 (horiz nystag) CN6 (bilateral abducens palsy), vestibular nuclei (nystag) - RAPIDLY REV W THIAMINE
ataxia wernickes encephcerbellar cortex and vestibular nuclei - takes longer to resolve than oculomotor - some permanent sx
mental status change wernickes encephdisorientation, apathy, dec attention span - these respond well to tx BUT memory and learning abil usu PERSIST (korsakoff)
korsakoff syndromedamage to ANT and DORSOMEDIAL thalamic nuclei - confabulation - unsure of fact and fill with story they think is true, anterograde amnesia
opsoclonus-myoclonus, truncal ataxia w extracranial tumorparaneoplastic syndrome of neuroblastoma - inc # of copies of N-myc MC extracranial neoplasm in child
wernig hoffmanfloppy child syndrome - ant horn cell damage
beri beri neuropathyPN demyelination weakness and areflex w pain and paresthesia, DISTAL LOWER LIMB
diabetic neuropathy sensory or motor deficitBOTH SENSORY AND MOTOR - nerve ischemia and osmotic nerve injury due to sorbitol accumn
drawing a clock oriented to time requestedexectuive fxn test
dementia dx criteriaimpairment across several cognitive domains and fxnal impairment in daily living activities
rapid correction of chronic hyponatremiaosmotic demyelination of CENTRAL PONS axons - central pontine myelinolysis - quadriplegia and pseudobulbar palsy (CN9,10,11)
SOD1ALS gene - codes for CU-Zn superoxide dismutase
which CN motor nuclei are loss in ALS5,9,10,12
memorize

Neuro - reflexes

Question Answer
cornealV1-7 (nasocilliary; temporal - orbicularis oculi)
lacrimationV1-7
jaw jerkV3-V3 (sensory spindle;masseter)
pupillary2-3
gag9-10
micturition1.sacral 2.pontine 3.cerebral
sacral micturitionS2-4 bladder CONTRACTION
pontine micturitionpontine reticular formation - ext urethral spincter relaxn and bladder contraction coordinatoin
cerebral micturitionINHIB SACRAL MIC. - damage causes URGE incontinence - empties when reflexively full - no sensation of fullness or control over bladder but ext spincter still intact
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Neuro - neurocuteaneous dz

Question Answer
VHLAD, cap hemiangioblastoma (retina and/or cerebellum), congential cysts (kindey, liver, pancreas), inc risk for BILAT RCC
von reckinghausens dzNF1, PNS tumor syndrome, neurofibromas,optic nerve gliomas, Lisch nodules, cafe au lait
NF2AD, bilat CN8 schwannomas and multiple meningiomas
Sturge-Weberencephalotrigeminal angiomatosis, cutaneous facial angiomas, leptomeningeal angiomas, overlie V1,V2 distribution; mental retardation, seizures, hemiplegia and skull radioopacities, tramtrack calcification
tuberous sclerosisAD, kidney, liver, pancreas cysts, angiomatous lesions (cortical and subependymal hamartomas), cutaneous angiofibromas (adenoma sebaceum), visceral cysts, RETINAL ANGIOLIPOMAS, and CARDIAC RHABDOMYOMAS, major complication SEIZURES, shaggy green patch and ash leaf spots
Osler-Weber-Renduhereditary hemorrhagic telangiectasia, AD congential telangectasias, epistaxis, GI bleeding, hematuria NO CYSTS
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Psych

MSK

Derm

Endo

Repro

Question Answer
prostate cancer tends to develop at gland ___periphery, urinary sx LATE in dz
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Biochemistry

Question Answer
anticipationfragile x and huntingtons
variable expressitivtymarfans
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Immunology

Question Answer
immune rxn in MShelper t cells target myelin antigens -> inflam cytokines promote infiltration of destructive macrophages/microglia and leukocytes; B cell - Ig bands
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Stats

Pharm – General

Question Answer
Alz dz tx targetsenhanced cholinergic transmission, neuroprotection (VitE) via antioxidants, NMDA R antagonism (memantine)
donepazil and ADAChEi - delays instituitonalizn and mortality
vigabatrinirrev inhib GABA transaminase (E responsible for GABA catabolism) used in TX RESISTANT EPILEPSY
DRESS syndromedrug induces herpes virus reactivation followed by clonal t cell expansion that cross rect w drug. drug rxn w eosinophilia and sys sx's, 2-8 w after exposure to high risk drugs such as ANTICONVLSANTS, allupurinol, sulfonamides, and ABs; DONT confuse w dressler (autoimmune pericarditis after MI)
DRESS syndrome sxfever, gen lymphadenopathy, facial edema, diffuse skin rash, eosinophilia, and internal organ dysfxn
atropine indicated for tx of bradycardia common PT W EYE PAIN AFTERSE acute closed angle glaucoma - mydriasis (diminish outflow of aqueous humor) - Asians and inuits at inc risk
Wilson dzCu chelators, d-penicillamin and trientine
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Pharm – Adverse Effects

Toxicology

Heme/Onc

Question Answer
high porphobiliogen in urine w ab pain, ascending muscle weakness and hyporeflexiaAIP - def of porphobilinogen deaminase (hydroxymethylbilane synthase)
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