UWorld System-Based Pathology Flashcards
6 cards from real UWorld practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 UWorld System-Based Pathology flashcards as text
In UWorld pharmacology, which antiarrhythmic drug class works by blocking sodium channels and is used for ventricular arrhythmias?
Answer: Class I antiarrhythmics (e.g., lidocaine, mexiletine, flecainide)
Class I antiarrhythmics block fast sodium channels, reducing phase 0 depolarization velocity; they are subdivided by their effects on action potential duration and are used for ventricular arrhythmias.
In UWorld embryology, failure of the neural tube to close at the caudal end results in which condition?
Answer: Spina bifida (myelomeningocele in severe cases)
Failure of caudal neural tube closure leads to spina bifida, ranging from spina bifida occulta to myelomeningocele, while cranial non-closure causes anencephaly.
What does UWorld emphasize as the primary mechanism of injury in acetaminophen overdose causing hepatotoxicity?
Answer: Accumulation of the toxic metabolite NAPQI when glucuronidation and sulfation are saturated, depleting glutathione and causing hepatocyte necrosis
In overdose, CYP2E1 metabolism produces excess NAPQI that exhausts glutathione stores, allowing NAPQI to covalently bind hepatocyte proteins and cause centrilobular necrosis.
In UWorld microbiology, which organism causes the classic 'rose spots' rash, relative bradycardia, and stepwise fever pattern in typhoid fever?
Answer: Salmonella typhi
Salmonella typhi causes typhoid fever characterized by stepwise fever, relative bradycardia (Faget's sign), salmon-colored rose spots on the trunk, and systemic infection via Peyer's patches.
In UWorld pathology, what is the significance of the Philadelphia chromosome (t(9;22)) in leukemia?
Answer: It creates the BCR-ABL fusion gene producing a constitutively active tyrosine kinase, driving uncontrolled myeloid proliferation in CML and some ALL cases
The t(9;22) translocation fuses BCR to ABL, creating a constitutively active tyrosine kinase that drives uncontrolled proliferation, targeted by imatinib (Gleevec) in treatment.
In UWorld renal pathology, what is the mechanism behind the hyponatremia seen in SIADH?
Answer: Excess ADH causes inappropriate free water reabsorption by the kidneys, diluting serum sodium without total body sodium depletion
In SIADH, persistently elevated ADH drives free water reabsorption via collecting duct aquaporins, expanding intravascular volume and diluting serum sodium with a euvolemic picture.