2023 USMLE Step 1 Test Bank NEW UPDATE WITH QUESTIONS AND CORRECT ANSWERS |GRADED A

2023 USMLE Step 1 Test Bank NEW UPDATE WITH QUESTIONS AND CORRECT ANSWERS |GRADED A Heterophile ab NEGATIVE Mono-like syndromes - ANSWER- *CMV HHV-6 HIV Toxoplasmosis Wernicke's Aphasia - ANSWER- -word salad: well-articulated, nonsensical speech paired with lack of lang comprehension -aud association cortex: post part of sup temporal gyrus - supplied by MCA Congenital Deficiency of Propionyl CoA Carboxylase - ANSWER- -prevents conversion of propionyl CoA to methylmalonyl CoA -propionyl CoA derived from= val, ile, met, thr, odd # FA, cholesterol side chains -Propionic Acidemia: poor feeding, vomiting, hypotonia, lethargy, dehydration, anion gap acidosis Down Synd Comorbidities - ANSWER- Neuro: MR, early onset Alzheimer's Cardio: complete AV septal defect, VSD, ASD GI: duodenal atresia, hirschprung disease Endo: hypothyroid, DM1, obesity Heme: ALL (> 5 yo) and AML (<5 yo) Rheumatology: atlantoaxial stability MCC of Hypoglycemia in EtOH-ics - ANSWER- Thiamine def= suppression of GNG (pyruvate DH) and TCA cyle (alpha-KG DH) MCC of Hypoglycemia in advanced renal insuff - ANSWER- impaired clearance of insulin Avoid Nitrates in Hypertrophic Cardiomyopathy bc... - ANSWER- Nitrates decrease preload, which will increase the LV outflow tract... BUT since the ventricle is abnormally shaped, there is an outflow obstruction Mets through BM - ANSWER- Clonal proliferation of cells can invade/ metastasize* 1. malignant cells to lose their cell-to-cell adhesion molecules (cadherins) 2. cell receptors to attach to laminin (a glycoprotein) in the basement membrane and to release metalloproteinases (e.g., collagenases, stromelysins, gelatinases) to degrade the basement membrane and other enzymes to degrade the interstitial connective tissue- tissue inhibitors of metalloproteinases neutralize these tumor-produced enzymes and limit the degree of invasion 3. cell receptors to attach to bronectin and other proteins in the extracellular matrix (ECM) and to break it down 4. malignant cells to produce cytokines that stimulate locomotion, so that they can move through basement membranes and the intracellular and extracellular matrices Bicuspid Aortic Valve - ANSWER- Commonly presents in young, asymptomatic patient with soft systolic ejection at right 2nd ICS -can cause aortic regurg MCC of Vaginal Candidiasis - ANSWER- 1. Abx use= reduces lactobacilli pop 2. High estrogen levels- preg 3. System corticosteroid therapy 4. Uncontrolled DM 5. Immunosuppression, including HIV Drug causes of SIADH - ANSWER- -Carbamazepine -Cyclophosphamide -SSRI MC Ankle Sprain due to inversion of plantar-flexed foot - ANSWER- -Ant Talofibular Lig dmg -ecchymosis at the ant-lat aspect of the ankle Upper Brachial Plexus Injury - ANSWER- - Musculocutaneous and Suprascapular N. - dystocia mc in neonates; severe trauma mc in adults - should adduction, elbow extension, and forearm pronation Patent foramen ovale - ANSWER- -failure of septum primum and septum secundum to fuse after birth -can lead to paradoxical emboli Ventricular Septal Defect - ANSWER- -MC occurs in membranous septum -Acyanotic at birth bc of L to R shunt Coronary Blood Flow Peak - ANSWER- -at Early Diastole -coronary perfusion driven by diastolic pressure -tachycardia will decrease coronary perfusion Right Dom Heart - ANSWER- majority of people -PDA comes off RCA -SA and AV nodes supplied by RCA Left Dom Heart - ANSWER- -PDA comes off of LCX - SA and AV node supplied by LCX Increased Pulse Pressure - ANSWER- hyperthyroidism, aortic regurgitation, aortic stiffening (isolated systolic hypertension in elderly), obstructive sleep apnea ( sympathetic tone), exercise (transient) Decreased Pulse Pressure - ANSWER- aortic stenosis, cardiogenic shock, cardiac tamponade, advanced heart failure (HF) Causes of Spontaneous Depol causing Tachyarrhythmias - ANSWER- Hypokalemia, Hypermagnesemia, or prolonged QT interval = all cause spontaneous depol of ventricles in phase 3 or 4 and it will cause an extra AP in heart Direct alpha 1 agonist mediated effects - ANSWER- - vasc smooth muscle contraction= increased afterload and venous return= increased DBP + SBP causes reflexive increase in vagal tone= dec HR and slowed AV conduction - mydriasis - increased internal urethral sphincter tone and prostate contraction Direct alpha 2 agonist mediated effects - ANSWER- - CNS med decrease in BP - decreased intraocular pressure - decreased lipolysis - decreased presyn NE release - increased platelet aggregation S. epidermidis - ANSWER- - coag neg -novobiocin sens - infective endocarditis and infective arthritis in prosthetic pts Asymptomatic heart defect in turner's synd - ANSWER- -nonstenotic bicuspid aortic valve -early systolic , high frequency click over right second IC space Cardiac Changes w/ Normal Aging - ANSWER- - decreased left ventricular chamber size - shortened base- to- apex dimension - ventricular septum becomes sigmoid and shape, with basilar portion bulging into LV outflow tract - atrophy of myocardium causes increased interstitial connective tissue, often with concomitant extracellular amyloid deposition - lipofucin pigment accumulation within cardiomyocytes ARDS - ANSWER- Characterized by the development of hypoxemia and bilateral pulmonary infiltrates in the absence of heart failure -begins with initial injury of pul alveoli (smoke inhal) or pul endothelium (sepsis) which leads to the recruitment of neutrophils- this worsens the situation and leads to intraalveolar accumulation and hyaline membrane formation -decreased lung compliance, increased work of breathing, worsened V/Q mismatch, and normal PCWP Renal Artery Stenosis (histo) - ANSWER- medial fibroplasia, absent internal elastic lamina in areas of aneurysmal dilation