uWorld 37 Flashcards
korsakoff syndrome is associated with damage to what
ANTERIOR and DORSOMEDIAL THALAMIC NUCLEI
results in memory loss (permanent) and confabulation (if they dont know a fact they will fill in the gaps with made up shit they think is true)
inability to form new memories (anterograde amnesia)
QT interval represents what
ventricular depolarization and repolarization
can be though of as a rough estimate of the action potential duration (APD)
what antiarrythmics prolong QT
class IA and III
amiodorone has very little risk of torsades tho
how does adenosine work ni treating PSVT
A1 rectors on cardiac cells to activate POTASSIUM channels, increasing potassium conductance
transient conduction delay through AV node is used for acute termination of PSVT
CD14 is a surface marker of what
monocyte-MACROPHAGE cell lineage
if mom with a son with sickle cell wants to have a kid with another man whats best way to see if her next child will have sickle cell
since her son has it we know she has sickle cell TRAIT (sickle cell disease is AR)
do PATERNAL HEMOGlOBIN ELECTROPHORESIS to see if the new partner also has sickle cell trait
inappropriate activation of what causes acute pancreatitis
TRYPSINOGEN
either ductal obstruction or direct parenchymal injury leads to ACINAR cell INJURY which results in INTRA-ACINAR CONVERSION of TRYPSINOGEN to TRYPSIN (done by lysosomal enzymes)
what do amylases do
hydrolyze starch to produce maltose (glucose-glucose disaccharide), trisaccharide maltotriose, and limit dextrins
impairment of what system can contribute to the development of neurodegenerative disorders such as parkinson’s and alzheimers
Ubiquitin-Proteasome system
mutations of the NOD2 gene have shown a particularly strong association with what
Crohn disease
it encodes an intracellular microbial receptor that recognizes bacterial lipopolysaccharides and subsequently activates NF-kappaB pathway
NK-kappaB is PROINFLAMMATORY TRANSCRIPTION FACTOR that increases CYTOKINE PRODUCTION
mutations in Crohns = impaired innate immune response
pertussis toxin incases cAMP production (via ribosylation of Gi) which leads to what
↑ INSULIN production
lymphocyte and neutrophil dysfunction
↑ SENSTIVITY to HISTAMINE
exogenous androgen (steroid) abuse INCREASES HEMATOCRIT in a dose-dependent mannor, why
testosterone stimulates red blood cell production (this is why normal hematocrit is higher in males than females)
lack of t-tubules in some myofibrils leads to what
uncoordinated contraction of individual fibers
impaired relaxation of the muscle after a SINGLE contraction occurs in what condition
myotonic dystrophy
AD disease due to abnormality of myotonia protein kinase resulting form a CTG trinucleotide repeat expansion
what forms the right lateral cardiac border on frontal chest xray
RIGHT ATRIUM
SVC
what form the anterior (sternal) surface and most of inferior border of the heart
right atrium
what is seen directly posterior to the esophagus on tranesophageal electrocardiography (TEE)
DESCENDING AORTA
good b/c you can see if it is dissected or aneurysm or something
the pulmonary artery ascends anteriorly and to the left of the ascending aorta and is directed toward the left shoulder, what is the course after it bifurcates
right pulmonary artery travels horizontally under the aortic arch posterior to the SVC
left pulmonary artery courses superiorly over the left main bronchus
what is the spread of neisseria causing meningitis
pharynx → blood → choroid plexus → meninges
transmitted via respiratory droplets (usuali asymptomatic carriers with nasopharyngeal colonization)
pharynx → lymphatics → meninges is how what organism causes meningitis
H. flu
infants and young children
middle ear → contiguous tissues → meninges how what organism causes meningitis
S. pneumonia (unusual way but its possible after an acute infection of the middle ear)
traumatic wound → leaking CSF → meninges how what organism causes meningitis
MCC of S AUREUS MENINGITIS or CNS ABSCESS
following penetrating skull injury or neurosurgery
primary lung focus → blood → meninges how what organism causes meningitis
TB or S. pneumonia
TB meningitis is chronic and characterized by monocytes and lymphocytes in the CSG primarily affecting the basal meningines
hemosiderin-containing macrophages in alveoli are suggestive of what
PRIOR episodes of pulmonary congestion and edema that arose due to chronic left heart failure
EPISODIC HYPERTENSION, TREMORS, HEADACHE, TACHYCARDIA, and DIAPHORESIS are highly suggestive of what
PHEOCHROMOCYTOMA (PC)
episodic due to fluctuation in catecholamine synthesis by the tumor
what are the hemodynamics of acute mitral valve regurgitation
↑↑ Preload (EDV) ↓ Afterload ↑↑ Ejection fraction ↓ foraward stroke volume ↓ ESV ↓ CO no change in contractile function
what are the hemodynamics of compensated mitral valve regurgitation
↑ Preload
↑ Ejection fraction
No change in after load, contractile function, or forward stroke volume
what are the hemodynamics of decompensated mitral valve regurgitation
↑ Preload (EDV) ↑ After load ↓ Contractile function ↓ ejection fraction ↓ forward stroke volume
what causes the hemodynamic changes seen in acute mitral valve regurgitation
high LA pressures and PULMONARY EDEMA so the LV need to accommodate regurgitated blood plus what normally comes from venous return, ↑ LV EDV (PRELOAD)
↑ preload and ↓ after load together = ↑ ejection fraction
however much of total stroke volume is lost to regurgitation into the LA, resulting in decreased forward stroke volume and reduced cardiac output (manifesting as HYPOTENSION and cardiogenic shock)
what causes the hemodynamic changes seen in chronic mitral valve regurgitation
compensatory LA enlargements allows the LA to receive the regurgicatnat column at lower filling pressure preventing pulmonary edema
chronic volume overload causes LV to undergo substantial enlargement due to eccentric hypertrophy
early on this will maintain forward stroke volume even in the setting of substantial regurgitant flow
after a while remodeling cause LV to becomes maladaptive and decompensated state occurs. IMPAIRED CONTRACTILITY reduces forward SV and increases left-sided filling pressures, causing decreased cardiac output and pulmonary edema
baby with CF on a HOT SUMMER DAY is vomiting and sleepy what is the electrolyte problem
HYPONATREMIA (they sweat out lots of SODIUM and CHLORIDE, hence the salt test)
they hypochloremia is typically asymptomatic so doesn’t cause the vomiting or sleepiness
what are risk factors for babies with CF getting hyponatremia, how is this managed
exclusive breast or formula feeding prior to the introduction of sodium rich, solid foods
high temperature environments
exercise (more sweating)
SALT SUPPLEMENTATION is recommended for patients with CF
CONSTIPATION, syncope and 2nd degree heart block in the setting of A FIB is likely due to what medication
calcium channel blocker (VERAPAMIL or DILTIAZEM)
frequently used for hypertension, angina pectoris, and supra ventricular arrhythmias
CONSTIPATION is a major side effect of non-DHP calcium channel blockers (verapil more than diltiazem)
what is indapamide
thiazide diuretic
what are the side effects of ethambutol
optic neuropathy:
decreased visual acuity, central scotoma, red/green color blindness
the ixodes tick is the vector for what
lyme
babesiosis (asplenic patients)
Anaplasma spp
what does babesiosis present as in a splenetomized patient
dyspnea
coarse crackles
bilateral infiltrates on CXR
procainamide, hydralazine, and isoniazid are all metabolized how
phase II ACETYLATION in the liver
SLOW ACETYLATORS are more susceptible to drug induced lupus
liver hydroxylation and hydrolysis are what type of metabolism
phase I
addition of of hydroxyl group reduces lipid solubility and facilitates excretion
liver sulfate conjugation is what type of metabolism
phase II
biotransforms drugs into MORE POLAR compounds that are more water soluble and easily excreted
succinylcholine, tetracaine, and remifentanil (all used for anesthesia) are metabolized how
plasma hydrolysis (esterase)
what type of nose bleed are most common
ANTERIOR
occur within the vascular watershed area of the NASAL SPETUM (anteroinferior part of the nasal septal mucosa) known as KIESSELBACH PLEXUS
several anastomosis in Kiesselbach plexus:
septal branch of the ANTERIOR ETHMOIDAL ARTERY
lateral nasal branch of the SPHENOPALATINE ARTERY
septal branch of the SUPERIOR LABIAL ARTERY (brach of the facial artery)
can be TREATED with CAUTERY (silver nitrate)
compression of the nasal alae while leaning forward stops a nose bleed from where
Kiesselbach plexus
what do the turbines (conchae) do
warm, humidify, and filter inspired air
expand and contract in response to environmental changes (temp, allergens, humidity)
they have a corresponding meatus which is a drainage pathway
the middle meatus drains what
frontal, maxillary, and anterior ethmoidal sinuses
MC site of NASAL POLYP
what is the most common site of a nasal polyp
middle meatus
the superior meatus proves drainage for what
sphenoidal and posterior ethmoid sinuses
posterior nose bleed are more severe and usually not treatable with cautery, what arteries are involved
branches of the sphenopalatine artery (also supply the posterior conchae)
co-adminsitration of phenytoin with what decreases the concentration of phenytoin in the plasma
CYP450 inducers (carbamazepine, barbs, griseofulvin, chronic alcohol consumption, rifampin)
most cases of SPORADIC colorectal cancer arise how
classic ADENOMA-CARCINOMA SEQUENCE (APC/beta-catenin pathway)
FIRST MUTATION is usually APC TUMOR SUPPRESSOR (regulates cell growth/adhesion)
seen in the LEFT side of the GI tract
micro satellite instability pathway of colorectal cancer is seen when
DNA mismatch repair gene mutations
implicated in Lynch Syndrome (HNPCC)
what are lab values in kleinfelters
↓ testosterone
↑ FSH, LH
↑ estradiol
new onset neurologic symptoms, anemia with schistocytes, thrombocytopenia, and acute kidney injury suggest what
THROMBOTIC THROMBOYTOPENIC PURPURA (TTP)
impaired function of ADAMTS13 which is a von-willebrand cleaving protease
excess von willebrant multipliers aid in hemostasis resulting in diffuse MICROVASCULAR THROMBOSIS
when the endometrium is no longer exposed to estrogen what happens
prostaglandin production increases, leading to VASOCONSTRICTION of SPIRAL ARTERIES
secretion of metallopreases by endometrial stromal cells (degradation of the extracellular matrix) and APOPTOSIS of the endometrium epithelium
under hypoxic conditions what drives conversion of pyruvate to lactate via lactate dehydrogenase
build up of NADH (due to hypoxia) inhibits PYRUVATE DEHYDROGENASE
patient who recently came back from mexico with maculopapular rash, purpuric lesions, hepatomegaly, thombocytopenia, leukopenia, and elevate liver aminotransferases
they had been to mexico 5 years before and got similar sickness that went away on its own
what they got, why is it worse this time?
DENGUE FEVER
worse because its a DIFFERENT SEROTYPE (SECONDARY infection can cause MORE SEVERE illness)
he has life long immunity to the first serotype he was infected with
what are the symptoms of dengue fever
classic:
- flu like febrile illness with marked myalgia and joint pains (“bone break fever”)
- RETRO ORBITAL PAIN
- rash (white islands in a sea of red)
Hemorrhagic fever: -increased vascular permeability thrombocytopenia spontaneous bleeding → SHOCK PROSITIE TOURNIQUET TEST (petechiae after sphygmomanometer cuff inflation for 5 infuse)
TX: supportive care
