UWorld_4.3 Flashcards
Pharmacokinetic characteristics of inhaled gases/anesthetics
- onset of action correlates with blood solubility (blood/gas partition coeff.)
- high blood/gas = blood saturates slowly ==> slower equilibration w/brain & slower onset of action
- low blood/gas = blood saturates rapidly ==> faster equilibration w/braind and rapid onset of action
- MAC = ~potency (inversely related)
Resistance for circuits in parellel & series
- [parallel] 1/RT = 1/R1 + 1/R2 + 1/R3 + ….
- [series] RT = R1 + R2 + R3 + ….
Hb actions @ lungs vs. peripheral tissues
- @ lungs: increased O2 binding ==> release of CO2 and H+ = “Haldane effect”
- @ periphery: high [CO2] & [H+] ==> O2 unloading
Characteristics of Acute Intermittent Porphyria + tx
- porphobilinogen deaminase deficiency
- usually asymptomatic ==> acute abdominal pain + N/V + neuro sx + reddish-brown urine (or recurring ab pain)
- tx =
- dextrose/glucose prep
- heme prep
- both ==I ALA synthase
What are smelly sweat glands called?
apocrine glands
Gram + rods that form “medusa” heads/serpentine ==> dx?
- bacillus anthracis
- pulmonary anthrax = woolsorters disease
- widening mediastinum (hemmorhagic mediastinitus)
- virulence = antiphagocytic capsule w/D-glutamate instead of polysacc
“Hot tub folliculitis”
- self-limited P.aeuruginosa infection from hot tub/pools that do not have adequate chlorination
- ==> papulopustular rash w/oxidase-positive gram-neg rods
Main energy source that drives gluconeogenesis
- GTP: faciliates OAA ==> PEP by PEPCK
- rxn that produces GTP = Succinyl CoA ==> Succinate
Methotrexate SE
- stomatitis = painful mouth ulcers
- hepatotoxicity = hepatitis, fibrosis, cirrhosis
- myelosuppression ==> increased infection risk
- B-cell lymphomas
- pulmonary fibrosis
- contraindicated in pregnancy
Encapsulated organisms
- H. influenza
- S. pneumo
- N. meningitis
- Salmonella
Indirect vs. Direct vs. Femoral hernias
- Indirect
- most common @ male infant
- enters inguinal ring
- lateral to inferior epigastric vessels
- due to persistent processus vaginalis & failure of closure of inguinal ring
- Direct
- most common @ older men
- bulges through Hesselbach’s triangle
- medial to inferior epigastric vessels
- ==> external inguinal ring
- due to weakness in transversalis fascia
- Femoral
- most common @ women
- potrudes through femoral ring
- medial to femoral vessels
- inferior to inguinal ligament
Characteristics of acute pancreatitis
- blockage ==> digestion of adipose by lipase
- calcium deposition + edema = acute interstitial
- if inflammation continues ==> acute necrotic pancreatitis
- chalky white fat necrosis + hemorrhage
- activation of proteolytic enzymes
Chronic lymphedema ==> increased risk for?
angiosarcoma
Terbanifine: MOA
- inhibits squalene oxidase ==> inhibition of fungal wall formation
- use = dermatophytoses; e.g. tinea corporis
branched-chain alpha ketoacid dehydrogenase coenzymes
- coenzymes = “TLC For Newborn (w/MSUD)”
- Thiamine pyrophosphate
- Lipoate
- CoA
- FAD
- NAD
- other enzymes w/same coenzymes
- pyruvate dehydrogenase
- alpha-ketoglutarate dehydrogenase
Schilling test results
- Administer parenteral B12 + oral radiolabeled B12
- high urinary excretion = normal absorption <== low dietary intake
- low urinary excretion = poor absorption
- Administer parenteral B12 + oral radiolabeled B12 + IF
- high urinary exretion = low IF is cause of poor absorption
- low urinary excretion = poor absorption is due to pancreatic/bowel problem
Gram (+) bacteria w/polar granules staining w/aniline dyes ==> dx?
- diptheria AB toxin = EF2 adp-ribosylation
Low vs. High frequency sound hearing @ inner ear
- high freq = @ base of cochlea, near oval and round window
- low freq = @ apex of cochlea, near helicotrrema
Ethambutol: MOA
- inhbiits arabinosyl transferae ==> inhibition of carbohydrate polymerization necc. for synthesis of TB cell wall
- not effective against non-TB bacteria
Intrafusal vs. golgi tendon organs @ muscles
- GTOs responsd to m. tension ==> connect to inhibitory interneurons of anterior horn motor
- (sudden relax in elevated tension)
- Intrafusal = responsd to passive strectch
- innervated by Ia and II sensory fibers
- DTRs
location of HMG-CoA
mitochondria of hepatocytes ==> cholesterol formation
Digoxin: MOA, use
- ==I Na-K-ATPase pump @ cardiac ventricular myocytes ==> Ca2+ accumulation ==> increased contractility
- acts on vagus nerve ==> decreased AV node condution
- 2nd line in Afib w/RVR
Polycythemia vera association
JAK2 mutation = non-receptor tyrosine kinase
Characteristics of abetalipoproteinemia
- defect in ApoB synthesis ==> inability to form chylomicrons & VLDL
- ==> fat accumulation @ epithelium of small intestine ==> foamy/clear appearace
Characteristics of contracture formation
- during wound healing: excessive MMP activity + myofibroblast accumulations @ wound margins ==> contracture
- produce deform @ wound/surround tissue
- most often @ palms, soles, ant. thorax, serious burn sites
Common cause of congenital bilateral agenesis of vas deferens
CF
Presentation of Reye synrome
- viral illness + tx with aspirin
- hepatic dysfxn ==>
- vomiting + hepatomegaly
- elevated ALT, AST, ammonia, bili, prolonged PT/PTTT
- biopsy = microvesicular steatosis w/out necrosis or inflammation
- encephalopathy = due to hyperammonia
CN IX fxn
- motor = stylopharyngeus
- parasym
- parotid gland secretion
- sensory
- post. 1/3 tongue
- typamic membrane/eustachian tube
- tonsillar region
- upper pharynx
- carotid body/sinus
PRPP synthase activation ==> increased pathway activity and consequences?
- ==> increased purine synthesis (+degredation) ==> gout
Target in gout tx
- PMNs
- via NSAIDs (COX inhibition)
- or (if NSAIDs contraindicated) then Colchichine: MT inhibition
(Tetrahydrobiopterin) BH4 cofactor importance
- inc synthesis of tyrosine, DOPA, serotonin, NO
- dihydrobiopterin reductase = enzyme that takes BH2 ==> BH4 in order for enzymes in this pathway to fxn
Trousseau’s syndrome + similar process in heart
- Trousseau = migratory thrombophlebitis
- similar = nonbacterial thrombotic endocarditis <==hypercoagulable state
Complication of tx of neonatal respiratory distress syndrome
- ==> retinopathy due to retinal neovascularization
Cause of amennorhea in anorexia
- loss of pulsatile secretion of GnRH from hypothalamus
MEN 1 =
MEN 2A =
MEN 2B =
- MEN 1 = “3Ps” = parathyroid, pituitary, pancreas
- MEN 2A = pheo, med carc thyroid, parathyroid
- MEN 2B = pheo, med carc thyroid, oral and intestinal mucosal neuromas
