Uworld 5 Flashcards
Combination therapy with simvastatin and cholestyramine results in?
synergistic reduction in plasma LDL levels
What is Henoch-Schonlien purpura?
IgA mediated small vessel vasculitis that manifests with palpable purpura on the lower extremities, abdominal pain, arthralgia/arthritis, and renal disease (hematuria +/- proteinuria)
Renal involvement is primarily due to IgA deposition in the mesangium
Timeframe for generalized anxiety disorder
equal/more than 6 months
excessive uncontrollable worry about multiple issues. Symptoms: restlessness, muscle tension, fatigue, sleep disturbance, irritability, and difficulty concentrating
What is primary biliary cholangitis?
Autoimmune disorder that most commonly affects middle-aged women and characterized by fatigue, pruritus, jaundice, cholestasis (eg elevated alkaline phosphatase, elevated gamma-glutamyl transferase, direct hyperbilirubinemia), and antimitochondrial antobodies
Histo finding for primary biliary cholangitis
dense lymphocytic portal tract inflammation with granulomatous destruction of interlobular bile ducts
Where is the most deoxygenated blood in the body?
Myocardial oxygen extraction exceeds that of any other tissue/organ; therefore, the cardiac venous blood in the coronary sinus is the most deoxygenated blood in the body.
Due to the high degree of oxygen extraction, increases in myocardial oxygen demand can only be met by an increase in coronary blood flow
The brachial artery can be injured when what nerve is injured?
Injury to the median nerve at the cubital fossa frequently injures the brachial artery
What is the course of the brachial artery?
The brachial artery runs alongside the median and ulnar nerves in the medial bicipital groove of the upper arm.
Proximal to the elbow, the median and ulnar nerves diverge, and the brachial artery continues with the median nerve through the cubital fossa.
Prolonged exposure to loud noises causes hearing loss due to damage of?
Due to damage to the stereociliated hair cells of the organ of Corti
What is mitochondrial encephalomyopathy?
Ragged red fibers on muscle biopsy and a maternal inheritance pattern
Why is the clinical presentation of mitochondrial encephalomyopathy varied in family members?
Clinical presentation in affected family members varies due to the degree of heteroplasmy, or proportion of mitochondria with normal and mutant genomes in the same cell or tissue
Pufferfish poisoning is caused by tetrodotoxin, a neurotoxin produced by microorganisms associated with the fish. Tetrodotoxin binds what?
Tetrodotoxin binds to voltage gated sodium channels in nerve and cardiac tissue, preventing sodium influx and depolarization
What is a cavernous hemangioma?
Cavernous hemangiomas are vascular malformation composed of abnormally dilated capillaries separated by thin connective tissue septa.
The lack of structural support gives them a tendency to bleed, and those that occur in the brain can present with neurological deficits and seizures
Rapid infusion of vancomycin can lead to what?
Can lead to the direct activation of mast cells, which results in a massive release of histamine. This causes vancomycin infusion reaction, a nonallergic reaction marked by flushing, erythema, and pruritus within seconds or minutes of vancomycin infusion.
Because this reaction is not IgE-mediated, vancomycin can be safely resumed at a slower rate once symptoms have resolved.
What is the first line treatment for obsessive-compulsive disorder?
Selective serotonin reuptake inhibitors
What do familial retinoblastoma patients have an increased risk for?
Familial retinoblastoma occurs as a result of mutations of each of the two Rb genes (“two hits”).
These patients have an increased risk of secondary tumors, especially osetosarcomas, later in life.
How does timolol (nonselective beta blocker) treat open-angle glaucoma?
Diminishing the secretion of aqueous humor by the ciliary epithelium
How does acetazolamide treat open angle glaucoma?
Acetazolamide, a carbonic anhydrase inhibitor) decreases aqueous humor secretion by the ciliary epithelium.
How does prostaglandin F2a (latanoprost, travoprost) and cholinomimetics (pilocarpine, carbachol) treat open angle glaucoma?
Decreases intraocular pressure by increasing the outflow of aqueous humor
What is open angle glaucoma?
Progressive loss of peripheral vision from elevated intraocular pressure
How does congenital syphilis present?
Acquired via transplacental transmission of the spirochete Treponema pallidum.
Present with pain and limited extremity movement due to long bone involvement (eg, metaphyseal erosions, periosteal inflammation).
Nonspecific: hepatosplenomegaly and lymphadenopathy
When do neural tube defects most often occur?
When the neural folds fail to fuse in the region of the anterior or posterior neuropores
An open neural tube defect allows leakage of what?
Leakage of alpha-fetoprotein and acetylcholinesterase into amniotic fluid.
Where is the left kidney in relation to the rib?
The left kidney lies immediately deep to the tip of the 12th rib.