NBME 30 TEST A VERIFIED QUESTIONS AND ANSWERS EXAM

NBME 30 TEST A VERIFIED QUESTIONS AND ANSWERS EXAM "Relative Risk - CORRECT ANSWER difference in likelihood of occurrence of a particular disease outcome between two groups of patients with or without a particular exposure (pt with exposure and disease/all with exposure)/(pt with disease but no exposure/all without exposure) [a/(a+b)] / [c/(c+d)]" "anterior hypothalamic nucleus - CORRECT ANSWER thermoregulation (cooling), parasympathetic" "arcuate hypothalamic nucleus - CORRECT ANSWER complex regulatory functions involved in appetite stimulation" "Dorsomedial Hypothalamic Nucleus - CORRECT ANSWER regulation of feeding (Meals) and circadian rhythm (Dreams) --> DM = dorsomedial" "posterior hypothalamic nucleus - CORRECT ANSWER thermoregulation (heating), sympathetic" "Chronic Granulomatous Disease (CGD) - CORRECT ANSWER X-linked form = most common deficiency of NADPH oxidase complex which is essential for normal neutrophil intracellular killing of pathogens; renders phagocytes incapable of neutralizing catalase positive bacteria recurrent pneumonia = most common presenting infection usually caused by Staph aureus, aspergillus species, Burkholderia cepacia, and Nocardia species see NO color change with nitroblue tetrazolium test (normal phagocytes use NADPH to reduce nitroblue causing color change from yellow to blue) see normal concentrations of leukocytes and immunoglobulins" "Chediak-Higashi syndrome - CORRECT ANSWER autosomal recessive mutations in lysosomal trafficking regulator gene --> microtubule dysfunction in phagosome-lysosome fusion PLAIN: Progressive neurodegeneration, Lymphohistiocytosis, Albinism (oculocutaneous), recurrent pyogenic Infection, peripheral Neuropathy see giant granules in granulocytes and platelets" "myeloperoxidase deficiency - CORRECT ANSWER inability to produce hypochlorous acid within phagolysosomes; mild disease, see recurrent candida albicans infection positive nitroblue tetrazolium test (presence of blue dye) because NADPH oxidase is still intact --> why disease is mild" "renal autoregulation - CORRECT ANSWER goal: maintain constant GFR despite changes in renal perfusion -hypoperfusion: decreased Na+ delivery sensed by macula densa cells = set off RAAS = increased efferent arteriolar resistance = maintenance of GFR -systemic HTN: opposite mechanism (increased Na+ delivery sensed by macula densa = inhibition of RAAS = decreased efferent arteriolar resistance)" "Acromegaly - CORRECT ANSWER -growth hormone secreting pituitary adenoma that stimulates excessive production of insulin-like growth factor 1 (IGF-1) from the liver --> IGF-1 stimulates growth of appendicular skeleton -occurs AFTER closure of growth plates -excessive GH and IGF-1 = deranged glucose homeostasis by increasing peripheral insulin resistance = decrease muscle uptake of glucose = increase lipolysis and hepatic gluconeogenesis" "Funisitis - CORRECT ANSWER infection of the umbilical cord that occurs in the setting of chorioamnioitis (bacterial infection of fetal membranes that most commonly occurs with premature or prolonged rupture of membranes)" "Effects of allosteric activators on enzyme kinetics - CORRECT ANSWER bind to allosteric site and induce conformational change in active site of enzyme which increases its affinity for substrate --> demonstrated as a decrease in Km (opposite seen for allosteric inhibitors)" "Chronic renal failure and effects on calcium, phosphorous and PTH levels - CORRECT ANSWER -active vitamin D = 1,25-dihydroxycholecalciferol --> synthesized through cutaneous, hepatic and renal routes -pt with CKD show decreased native vitamin D synthesis due to parenchymal damage = impaired GI uptake of dietary calcium = hypocalcemia -CKD also inhibits kidney's ability to excrete phosphate leading to hyperphosphatemia -low Ca2+ and high phosphate = upregulation of parathyroid hormone leading to secondary hyperparathyroidism -PTH increases bone turnover in order to increase serum Ca2+" "Phases of clinical trials - CORRECT ANSWER 1: small number of healthy volunteers receive treatment to assess safety, toxicity, adverse effects, interactions 2: trial of intervention on patients to have the disease to be treated; assess efficacy and dosing 3: larger, randomized controlled trial for treatment vs placebo/standard of care; assess if new intervention is equivalent to, better than, or worse than control 4: post distribution and post-prescription surveillance following treatment approval; reports made to FDA" "Adherens junctions (zonulae adherentes) - CORRECT ANSWER epithelial cell junctions which connect actin cytoskeletons of adjacent cells to each other defects (such as when E-cadherin expression is lost in cancer) allow for cells to metastasize" "Leukocyte adhesion deficiency (type 1) - CORRECT ANSWER defect in LFA-1 (CD 18) integrin on phagocytes = impaired migration and chemotaxis ***late separation of umbilical cord (>30 days)*** absent pus, dysfunctional neutrophils, recurrent skin and mucosal bacterial infections" "bursitis - CORRECT ANSWER inflammation of bursa (thin, sac-like, fluid-filled structures that reduce friction and permit motion between layers of connective tissue) see pain with palpation, swelling, erythema, but intact range of motion common ones = subacromal bursa, trochanteric bursa, olecranon bursa" "Renal papillary necrosis -pathophysiology -causes -presentation - CORRECT ANSWER -occurs following ischemic, inflammatory, infectious or toxin-mediated damage to the renal papilla; sloughing and loss of papillae -triggered by infections (ex: acute pyelonephritis), DM, sickle cell disease (common; secondary to renal medullary ischemia and infarction), NSAIDs -gross hematuria, proteinuria, acute flank pain" "Zellweger syndrome -inheritance -pathophysiology -histology -clinical presentation -labs -treatment and prognosis - CORRECT ANSWER -autosomal recessive -defect in PEX gene = impaired peroxisome synthesis (peroxisome = cholesterol/bile acid synthesis, metabolism of very long chain fatty acids) -foamy, lipid filled hepatocytes and necrosis -seizures, intellectual disability, hypotonia, hepatomegaly, kidney disease, cataracts, hearing loss, craniofacial abnormalities -increased VLCFAs, AST, ALT and direct bilirubin -no treatment; life expectancy less than 6 months of age" "External validity - CORRECT ANSWER determines whether an experiment can be generalized and tis conclusions applied to groups beyond those considered in the study population see in studies that have wide representation in gender, socioeconomic and ethnic breadth, and wide financial and insurance status --> likely to capture a sample that represents whole population" "Peutz-Jeghers syndrome - CORRECT ANSWER autosomal dominant, hamartomatous polyps in colon and GI tract, pigmented macules in mouth/lips/hands/genitalia hamartomatous polyps can present with intussusception, bowel obstruction, microcytic anemia" "Cowden disease - CORRECT ANSWER autosomal dominant polyposis with hamartomatous polyps in GI tract mucocutaneous neuromas, oral papillomas, cutaneous tichilemmomas" "Gardner Syndrome - CORRECT ANSWER familial adenomatous polyposis; autosomal dominant; thousands of adenomatous polyps arising after puberty associated with osteomas, soft tissue tumors, supernumerary teeth, hypertrophy of retinal pigment epithelium" "Muir-Torre syndrome - CORRECT ANSWER hereditary nonpolyposis colorectal cancer; prone to developing colon, GU, or skin cancers cutaneous manifestations = keratoacanthomas, sebaceous gland tumors" "cells responsible for blood testis barrier - CORRECT ANSWER sertoli cells via tight junctions = immune protected site since developing spermatozoa may contain genetic material that is foreign to body as a result of recombination during meiosis destruction of barrier = elicit immune response = autoantibodies against gametes" "Severe Combined Immunodeficiency (SCID) - CORRECT ANSWER severe impairment of both B and T cel function = recurrent bacteria, viral, and fungal infections -caused by many different mutations -FTT, severe lymphopenia with impaired cellular and humoral immunity" "duodenal ulcer perforation -pathophysiology -imaging -clinical presentation - CORRECT ANSWER -perforation = bowel contents released into peritoneal space = peritonitis --> abdominal rigidity, rebound tenderness, guarding -upright CXR = air under diaphragm (pneumoperitoneum) caused by leakage of bowel contents into peritoneal cavity -severe, diffuse abdominal pain, nausea, vomiting, fever, tachycardia, septic shock ***perforated viscus and resulting peritonitis = surgical emergency requiring exploratory laparotomy***" "exceptions to parental consent of testing and treatment of minors (< 18 years of age) - CORRECT ANSWER medical care related to sex (STDs, contraception, pregnancy care), substance use, life-threatening medical or psychiatric conditions" "Prevalence vs incidence - CORRECT ANSWER -prevalence = number of cases of a disease/condition as a fraction of a population in consideration -incidence = number of new cases over the total population at risk over a specified period of time (does not include subjects that have already developed the condition prior to the time point in question) -chronic condition: prevalence increases over time and exceeds incidence -acute condition: prevalence and incidence are similar" "primary cause of SCID - CORRECT ANSWER -adenosine deaminase deficiency; autosomal recessive -accumulation of deoxyadenosine (dATP; purine derivative) in purine salvage pathway --> inhibits ribonucleotide reductase = prevents DNA synthesis in B and T cells -Tx = stem cell transplant (curative) and enzyme replacement" "Lesch-Nyhan syndrome - CORRECT ANSWER X-linked recessive disorder characterized by intellectual disability, signs of cerebral palsy, and self-mutilation -deficiency in HGPRT = impaired conversion of hypoxanthine to IMP and guanine to GMP (i.e inability to utilize purine salvage pathway) = excess uric acid (due to degradation) and increase in de novo purine synthesis -see orange sand-like sodium urate crystals in urine, gouty arthritis" "Bethanechol - CORRECT ANSWER direct cholinergic agonist at muscarinic receptors but not nicotinic used to treat urinary retention (Bladder) and gastric dysmotility (Bowel) not metabolized by acetylcholinesterase but actions can be blocked by atropine" "Normal pressure hydrocephalus - CORRECT ANSWER -type of communicating (non-obstructive) hydrocephalus in which ventricles are enlarged = damage to white matter tracts connecting frontal lobes and basal ganglia -dementia (frontal executive dysfunction), wide-based or magnetic gait, urinary incontinence, postural instability, nystagmus --> "Wet, Wobbly, Wacky" -signs of increased ICP (headaches, papilledema) are absent -many cases are idiopathic -Tx = ventricular shunting" "Pick disease - CORRECT ANSWER -aka frontotemporal dementia --> neurodegenerative disorder characterized by atrophy of frontal and temporal lobes -deficits in social behavior and personality along with dementia" "Ehrlichiosis -microbe and epidemiology -transmission -presentation -labs -treatment - CORRECT ANSWER -ehrlichia chaffeensis = intracellular bacterium endemic to southeast, mid-atlantic and central US -tick borne -fever, headache, mylagias, NO RASH -thrombocytopenia, leukopenia, increased AST, ALT -doxycycline (think: when you LICK someone, there is no rash left behind)" "Type 1 hypersensitivity reaction - CORRECT ANSWER -early (within minutes of allergen exposure; lasts 1-2 hours): crosslinking of IgE on sruface of basophils and mast cells = degranulation and release of cytokines (histamine, prostaglandins, leukotrienes) -late (2-8 hours after mast cell activation): recruitment of inflammatory cells (predominantly eosinophils) to nasal mucosa" "Type 1 error - CORRECT ANSWER -likelihood of erroneously rejecting the null hypothesis (and concluding there is a statistically significant relationship when there is not) -equal to alpha (%) which converted to a decimal is equal to the p value -ex: if p = 0.05, then alpha = 5% --> 5% likelihood of making a type 1 error ***think: in order to be #1, scientists will say experiment is right even when it is not***" "Type 2 error - CORRECT ANSWER -study demonstrates NO difference when in fact one exists -Power (1-beta) = probability of rejecting a null when it is true; Beta = probability of committing a type II error -ex: if power = 80% , then beta = 20%" "partial agonist - CORRECT ANSWER drug binds to and activates receptor at same site as full agonist but has decreased efficacy (decreased Vmax)" "major form of thyroid hormone found in circulation - CORRECT ANSWER T4 bound to T4-binding globulin" "identifying cardiac valves on CXR - CORRECT ANSWER on lateral view, draw line from carina to apex --> pulmonic and aortic are superior to line, tricuspid and mitral are inferior" "ACTH hypersecretion from pituitary adenoma vs small cell lung cancer - CORRECT ANSWER both show Cushing Syndrome, but adenoma will respond to feedback inhibition from exogenous dexamethasone administration where as small cell lung paraneoplastic syndrome will not" "diabetic neuropathy - CORRECT ANSWER chronic hyperglycemia = formation of advanced glycation end products in vascular endothelium = capillary damage t/o body, including within vasa nervorum (vessels that supply blood to peripheral nerves) ischemic nerves = upregulation and persistent activation of VG-Na+ channels in nociceptor = increased production of action potentials causing sensation of pain -Tx = TCA, carbamazepine (both have Na+ channel blocking properties)" "changes in CVP, MAP and PCWP with decreased cardiac contractility - CORRECT ANSWER decreased contractility = reduced stroke volume and decreased forward flow of blood CVP = increased --> blood pooling in venous system MAP = decreased --> less blood going into systemic circulation PCWP = increased --> blood backing up into LA" "changes in cardiac status with change of position from standing to supine - CORRECT ANSWER standing to supine = influx of blood from lower body to upper body caused by gravity = increased preload = increased SV and LV end diastolic volume increased amount of blood in systemic circulation = sensed by baroreceptors = reflex decrease in HR" "arteriovenous PO2 difference in hypovolemic shock - CORRECT ANSWER arteriovenous oxygen difference = indication of how much oxygen is removed in capillaries as blood circulates shock = state of low organ perfusion --> oxygen extraction in tissue is increased = increased arteriovenous PO2 difference" "Tinea (pityriasis) versicolor - CORRECT ANSWER -superficial myocsis; Malassezia furfur (yeast) -hyper and hypogimentation in areas with lots of sebaceous secretions (upper torso, arms, scalp) -skin lesions fluoresce under Wood's lamp -"spaghetti and meatballs" appearance = fungal spores and short hyphae along edges of epidermal cells" "Dermatophytoses (tinea) - CORRECT ANSWER cutaneous mycoses; trichophyton, epidermophyton, microsporum -tinea capitis, pedis, corporis, cruris, unguium, barbae" "amyloidosis - CORRECT ANSWER deposition of small molecular weight, insoluble proteins in various tissues resulting in progressive organ dysfunction --> ex: hepatomegaly, macroglossia, cardiac conduction abnormalities, Sx of restrictive cardiomyopathy, nephrotic syndrome protein fragments commonly derived from immunoglobulin light chains = AL amyloidosis (subtype of amyloidosis; most common; light chain amyloidosis) --> can be caused by plasma cell dycrasias (ex: multiple myeloma) second most common form = reactive amyloidosis (AA amyloidosis; serum amyloid A protein deposition) --> secondary to chronic inflammation; typically presents with nephrotic syndrome" "embryologic development of kidneys - CORRECT ANSWER -during development, several primitive renal structures form: pronephros, mesonephros, and metanephros -metanephros: only one that contributes to ultimate formation of kidney (other 2 structures degenerate) -ureteric bud forms as out pouching of mesonephric duct -normal renal embryologic development is dependent on reciprocal inductive signaling between ureteric bud and metanephros --> ureteric bud forms collecting ducts under influence of metanephros; metanephros forms renal tubules in response to ureteric buds" "Immune Thrombocytopenic Purpura (ITP) - CORRECT ANSWER autoimmune destruction of platelets with subsequent development of thrombocytopenia bone marrow biopsy shows increased number of megakaryocytes (indicates adequate production) see petechiae and purpura due to microhemorrhages into skin and prolonged bleeding time" "Thrombotic Thrombocytopenic Purpura (TTP) - CORRECT ANSWER thrombotic microangiopathy --> microthrombi consisting primarily of platelets form and occlude microvasculature --> can lead to end organ ischemia and damage primarily in adults; due to acquired autoantibodies against or gene mutations in a proteolytic enzyme (ADAMTS13) classic pentad: (1) fever (2) neurological abnormalities (3) microangiopathic hemolytic anemia [due to mechanical damage of RBCs by microthrombi in vasculature = schistocyte] (4) thrombocytopenia (5) impaired renal function ***Hematologic emergency*** --> Tx with plasma exchange ASAP (fatal if untreated)" "opiate withdrawal Sx - CORRECT ANSWER restlessness, tachycardia, hypertension, pupillary dilation, tremors, muscle cramping, abdominal cramping, NVD, lacrimation, rhinorrhea, ***yawning and piloerection*** (not seen withdrawal from other recreational drugs)" "lymph node drainage of testis - CORRECT ANSWER para-aortic (lumbar) lymph nodes --> same for ovaries" "relationship between blood flow, diameter and resistance - CORRECT ANSWER blood flow (quantity/unit time) = pressure/resistance resistance = length x viscosity/pie x radius ^4 decrease in vessel radius = large increase in resistance = decrease in blood flow" "Blood Flow vs Blood Velocity - CORRECT ANSWER flow = mL/sec --> quantity/time velocity = m/sec --> distance/time --> velocity decreases with an increase in cross-sectional area" "cystic hygroma - CORRECT ANSWER aka lymphangioma --> cystically dilated sac filled with lymph fluid caused by obstruction of the lymphatic system; lined with endothelium associated with Turner syndrome (45, XO)" "estrogen and thyroid hormone relationship - CORRECT ANSWER increase in estrogen (endogenous [ex: pregnancy] or exogenous) = increased levels of transport proteins such as thyroid hormone binding globulin increase in thyroid hormone binding globulin = increased total thyroid hormone concentration (because more in bound state) but unchanged free thyroxine and TSH concentrations" "Mucopolysaccharidoses (MPS) -common pathophysiology -types -presentation - CORRECT ANSWER -lysosomal storage disorder caused by enzyme deficiency that prevents degradation of glycosaminoglycans (heparan and dermatan sulfate) in lysosome = buildup of atypical substrates in lysosomes -MPS I = Hurler syndrome; alpha-iduronidase deficiency; autosomal recessive; coarse facial features, corneal clouding, hepatosplenomegaly, skeletal abnormalities (dysostosis multiplex), joint contractures, intellectual disability, developmental delay, heart failure, hydrocephalus, hearing loss, recurrent respiratory tract infections; life span = 5 years --> usually due to MI from deposition of dermatan and heparan sulfate within vessels -MPS II = Hunter syndrome; deficiency in iduronate-2-sulfatase; X-linked recessive; milder features of Hurler but with absence of corneal clouding and addition of aggressive behavior and pearly papular skin lesions; life span = 13-20 years" "benzodiazepines and GABA receptors - CORRECT ANSWER benzos = postitive ALLOSTERIC modulators of GABAa receptors (bind different site on receptor than GABA)" "Carcinogens associated with urothelial cancer (transitional cell carcinoma) - CORRECT ANSWER phenacetin, cyclophosphamide, 2-naphthylamine --> all found in cigarettes" "myasthenia gravis -pathophysiology -pregnancy - CORRECT ANSWER autoantibodies to nicotinic Ach receptors on skeletal muscle cells pregnancy can exacerbate Sx; nAChR antibodies may be transmitted transplacentally (need to monitor neonates)" "bradykinin - CORRECT ANSWER potent vasodilator and protussive mediator; normally degraded by ACE ACE inhibitors = increased [bradykinin] = persistent, nonproductive cough" "reflux nephropathy - CORRECT ANSWER renal damage secondary to vesicoureteral reflex (VUR) which is retrograde flow of urine from bladder into ureters and renal calyces VUR begins in childhood and occurs because of anatomical abnormalities in structure of ureteric valves; increases risk for recurrent UTI; severe = renal parenchymal atrophy and chronic renal failure" "atypical lymphocytes in EBV infection - CORRECT ANSWER recall: EBV infects B cells via binding of CD21 however, atypical lymphocytes seen on peripheral smear are cytotoxic CD8+ T cells which are reacting to the viral infection rather than infected B cells" "pol gene HIV - CORRECT ANSWER 1. reverse transcriptase 2. integrase 3. protease "RIP Pol"" "VIPoma - CORRECT ANSWER rare tumor associated with MEN that produces vasoactive intestinal peptide (increases secretion of water and electrolytes and increases relaxation of intestinal sphincters and smooth muscle) Sx = chronic and profound watery diarrhea, hypokalemia, hypercalcemia, achlorhydria, alkalosis, flushing, vasodilation" "vitamin E - CORRECT ANSWER fat soluble vitamin; antioxidant that protects cells from free radical damage deficiency = hemolytic anemia, generalized muscle weakness, posterior column and spinocerebellar tract demyelination" "part of the brain that is highly susceptible to hypoxic injury - CORRECT ANSWER hippocampus due to high metabolic demands hypoxia = no ATP production = increased intracellular Na+ concentration due to dysfunction of Na/K ATPase = pulls water into cells = edematous (large) neurons" "cross sectional study - CORRECT ANSWER seeks to identify prevalence of a condition at a particular point in time --> risk factor and outcomes are measured simultaneously (all information collected at single time point" "cohort study - CORRECT ANSWER identifies group of patients with or without exposure and follows them over time to identify whether exposure is associated with outcome of interest" “pellagra - CORRECT ANSWER acquired deficiency of niacin (nicotinic acid, vitamin B3); Sx = diarrhea, dementia, dermatitis" "Hartnup disease - CORRECT ANSWER autosomal recessive disorder of decreased GI absorption of tryptophan which is the precursor to nicotinic acid (niacin, vitamin B3); see pellagra-like Sx = diarrhea, dementia, dermatitis (3 D's with Vitamin B3 deficiency)" "scurvy - CORRECT ANSWER deficiency of vitamin C; signs and Sx of impaired collagen synthesis = swollen bleeding gums, easy bruising and bleeding, petechiae, impaired wound healing, short fragile curly hair" "Vascular changes as a result of chronic hypertension - CORRECT ANSWER see changes in small arteries and arterioles = arteriosclerosis --> thickening of vessel walls and loss of elasticity (1) Hyaline arterioscerolosis = protein deposition in vessel walls (2) Hyperplastic arteriosclerosis (aka hyperplastic arteriolitis) = concentric thickening of vessel wall with laminar appearance caused by proliferation of smooth muscle cells; associated with severe, chronic HTN" "lateral hypothalamic nucleus - CORRECT ANSWER promotes appetite under stimulation of ghrelin (your stomach growls if you're late to lunch)" "ventromedial hypothalamic nucleus - CORRECT ANSWER promotes satiety under stimulation of leptin (ventro sounds like "biento" = i'm good (full))" "supraoptic and paraventricular nuclei - CORRECT ANSWER synthesize ADH and oxytocin" "osteopetrosis - CORRECT ANSWER disease of excessive mineralization of bone leading to abnormally dense bone due to failure of osteoclastic resorption recall: osteoclasts arise from monocyte-macrophage lineage --> defects in signaling of macrophage CSF play role in pathogenesis" "porphyria cutanea tarda - CORRECT ANSWER most common porphyria; decreased activity of uroporphyrinogen decarboxylase = lack of heme synthesis + accumulation of uroporphyringogen III --> deposited into skin and produce ROS when excited by sunlight Sx= severe cutaneous photosensitivity with blistering and hyperpigmentation after exposure to sunlight" "Precursors to catecholamines - CORRECT ANSWER phenylalanine --> tyrosine --> dopamine, epinephrine, norepinephrine" "phenylketonuria (PKU) - CORRECT ANSWER deficiency in phenylalanine hydroxylase which converts phenylalanine to tyrosine build up of phenylalanine = failure to reach milestones, microcephaly, hyperactivity, seizures, intellectual disability, mousy odor of skin and urine must supplement diet with tyrosine in order to produce catecholamines" "bacterial transformation - CORRECT ANSWER ability of bacteria to take up and incorporate genetic material (naked DNA) that is not associated with proteins or lipids from the environment promotes genetic diversity and acquisition of survival advantage" "Brief psychotic disorder - CORRECT ANSWER at least one acute psychotic symptom (delusions, hallucinations, disorganized speech, disorganized behavior) lasting less than 1 month" "when does placenta become primarily responsible for progesterone production? - CORRECT ANSWER 7-10 weeks of gestation; before that, progesterone is secreted by the corpus luteum which is being maintained by hCG" "neutrophil-specific granule deficiency - CORRECT ANSWER defective production of granules within neutrophils; recurrent pyogenic infections that occur early in childhood + impaired production of defensins normal nitroblue tetrazolium test" "Wiskott-Aldrich syndrome - CORRECT ANSWER X-linked recessive mutation in WAS gene on X chromosome --> leukocytes and platelets unable to reorganize actin cytoskeleton --> defective antigen presentation WATER: Wiskott-Aldrich Thrombocytopenia, Eczema, Recurrent pyogenic infections" "most common primary brain tumor in adults - CORRECT ANSWER meningioma; malignant or benign --> malignant cause Sx of increased ICP such as headache well-circumscribed, extra-axial masses that compress adjacent brain parenchyma; see psammoma bodies" "pores of Kohn - CORRECT ANSWER connections between alveoli that are present in normal lung tissue aid in normal oxygenation and prevention of atelectasis by allowing equilibration between adjacent alveoli also allow passage of fluid, phagocytes and bacteria (in setting of pneumonia --> how whole lobe involvement can occur)" "Waardenburg Syndrome -inheritance -etiology -clinical presentation -diagnosis - CORRECT ANSWER -autosomal dominant -abnormality in neural crest development such that neural crest cells do not properly differentiate into melanoblasts (melanocyte precursors) or melanoblasts do not migrate to proper location -white forelock in hair, white eyelashes, depigmented skin patches, iridic heterochromia, sensorineural hearing loss, laterally displaced eyes -audiologic evaluation and genetic testing" "HIV encephalopathy - CORRECT ANSWER -diagnosis of exclusion; classic triad = (1) movement disorders (2) psychomotor impairment (3) memory deficits -imaging: multiple, symmetric, poorly demarcated T2 hyperintense lesions scattered in subcortical white matter -brain biopsy: microglial nodules with multinucleated giant cells -DDx: PML (more rapid disease progression, focal deficits, different MRI findings) vs Primary CNS lymphoma (MRI with dominant cortical mass not multiple lesions)" "Carotid Sinus Syndrome - CORRECT ANSWER exaggerated response to carotid baroreceptor stimulation = sinus bradycardia, hypotension, syncope may be exacerbated in setting of volume depletion (ex: diuretic use)" "Complications of Monochorionic twin gestation - CORRECT ANSWER (1) Twin-twin transfusion syndrome (TTTS) = formation of arteriovenous anastomoses in chorion of placenta that allows blood to pass from one fetus to the other (2) Twin Anemia Polycythemia Sequence (TAPS) = presentation of TTTS with one twin having anemia (low hematocrit) and the other twin having polycythemia (high hematocrit) can see discordant amniotic fluid indices, congenital anatomic abnormalities, hydrops fetalis, heart failure, intrauterine growth restriction" "Manifestations of chronic alcohol withdrawal - CORRECT ANSWER sympathetic overdrive (since alcohol is a CNS depressant) -initially: tremors, anxiety, diaphoresis, HTN, tachycardia, nausea -within hours of last drink: alcoholic hallucinations (auditory or visual without confusion or autonomic instability) and seizures (due to cortical hyperactivity) -Delirium tremens: most concerning and life threatening --> severe confusion, disorientation, fluctuations in consciousness, agitation, visual hallucinations, autonomic instability (fluctuations in pulse, BP with hyperthermia)" "de Quervain thyroiditis - CORRECT ANSWER aka subacute granulomatous thyroiditis self-limited thyroiditis that often follows an acute viral illness Sx of hyperthyroidisim --> diaphoresis, palpitations, neck pain, dysphagia, fever, tachycardia increased T3 and T4, decreased TSH may become hypothyroid or euthyroid following acute inflammation ***characteristic = PAINFUL, tender thyroid***" "Euthyroid sick syndrome - CORRECT ANSWER occurs in setting of acute systemic illness decreased concentrations of thyroid hormone but with euthyroid clinical appearance does not present with enlarged or tender thyroid" "Autoimmune hemolytic anemia (AIHA) -etiology -diagnosis -clinical presentation - CORRECT ANSWER result of binding of an autoantibody to RBC surface antigens leading to removal of RBC via RES (phagocytosis) or intravascular hemolysis (via complement) diagnosis made by positive Coomb's test clinical presentation: unconjugated hyperbilirubinemia (jaundice) and increased reticulocyte count" "Cellular presentation in myocardial ischemia and myocardial infarction - CORRECT ANSWER -ischemia: lack of blood flow = decreased oxygen = cells unable to produce ATP = inhibit function of Na/K ATPase = Na+ retention in cell = water enters cell and causes SWELLING (first sign of reversible cell damage) -infarction: irreversible cell injury = cell death; see defects in plasma membrane, nuclear pyknosis, rupture of lysosomes" "treatment of herpes simplex virus infection - CORRECT ANSWER -acyclovir, valacyclovir, famciclovir --> guansine analogues that inhibit viral DNA polymerase by terminating nascent DNA chain during replication -need to first be phosphorylated by viral thymidine kinase" "hemochromatosis -inheritance -pathophysiology -clinical manifestations -diagnosis - CORRECT ANSWER -acquired (secondary to multiple blood transfusions) or inherited (autosomal recessive) -abnormally increased intestinal absorption of iron (with inherited genetic defect) = iron accumulation in liver, pancreas, skin, heart joints --> increased free radical generation and cause failure of affected organs -liver failure (cirrhosis and portal HTN), DM, arthritis, cardiomyopathy w/ Sx of heart failure, darkening of skin, gonadal atrophy -biopsy shows iron deposition with Prussian blue stain" "purpose of positive end expiratory pressure - CORRECT ANSWER prevent pressure in alveoli from dropping to zero or becoming negative during respiratory cycle --> keep alveoli open and able to participate in gas exchange (prevent atelectasis)" "how to prevent tension pneumothorax during mechanical ventilation - CORRECT ANSWER using lung-protective tidal volume strategies and close monitoring of peak inspiratory pressure --> large tidal volumes or high peak pressure can cause alveolar sac rupture and air communication into pleural space = tension pneumothorax" "Pathophysiology of Alzheimers - CORRECT ANSWER amyloid plaques, neurofibrillary tangles, atrophy of cholinergic neurons (which originate from basal nucleus of Meynert in basal forebrain) = decreased cholinergic signaling in cerebral cortex and basal forebrain" "chronic kidney disease and vitamin D - CORRECT ANSWER -decreased levels of active vitamin D (1,25-dihydroxycholecalciferol) because conversion of 25-hydroxycholecalcifierol to 1,25 takes place in kidney (via 1-alpha-hydroxylase) -deficiency of vitamin D = decreased intestinal absorption of calcium" "endochondral ossification - CORRECT ANSWER bone is indirectly formed from mesenchymal cells via cartilaginous model -bones of limbs, axial skeleton (vertebrae, ribs), base of skull" "intramembranous ossification - CORRECT ANSWER bone is formed directly from mesenchymal connective tissue with no cartilaginous model -facial bones, parts of the calvarium, clavicle" "cleidocranial dysplasia (CCD) -inheritance -pathophysiology -clinical presentation - CORRECT ANSWER -de novo or autosomal dominant -CBFA1 gene mutation --> normally codes for a transcription factor involved in osteoblast differentiation --> therefore, disease = issue with osteoblast differentiation -delayed closure of cranial sutures, craniofacial dysmorphism (frontal blossing, prominent chin, maxillary hypoplasia), dental abnormalities (supernumerary teeth), hypoplastic clavicles, hypertelorism" "lead poisoning - CORRECT ANSWER -affects central and peripheral nervous systems, heme synthesis pathway (inhibition of ferrochelatase and ALA dehydratase), GI and kidney function -Sx = neurobehavioral symptoms (hyperactivity, decreased attention span), hearing loss, peripheral neuropathy, renal tubular dysfunction, interstitial nephritis, vomiting, abdominal gain, constipation, anemia -basophilic stippling on peripheral blood smear and ringed sideroblasts within bone marrow" "Familial hyperchylomicronemia - CORRECT ANSWER -autosomal recessive lipoprotein lipase deficiency --> lipoprotein lipase catalyzes conversion of triglyercides carried by circulating chylomicrons into fatty acids that can be absorbed by cells for use in metabolism -increased serum concentrations of chylomicrons and triglycerides -abdominal pain following ingestion of fatty meals and steatosis, eruptive xanthomas, lipemia retinalis (cream colored discoloration of retinal vessels) -buildup of chylomicrons and triglycerides in serum = milky appearance and increased serum amylase activity" "councilman body - CORRECT ANSWER hepatocytes in state of apoptosis or necrosis; possess small nuclear fragment but no distinct nucleus and intensely eosinophilic cytoplasm seen in both acute and chronic hepatitis" "Ataxia Telangiectasia -inheritance -pathophysiology -presentation - CORRECT ANSWER -autosomal recessive -defect in DNA repair --> somatic mutations accumulate = dysfunction of diverse proteins, increased susceptibility to hematologic malignancy (such as Hodgkin lymphoma) -progressive ataxia, telangiectasias of eyes and exposed areas of skin, abnormal eye movements, decreased immunoglobulin concentrations (leading to recurrent sinopulmonary infections)" "murmur associated with idiopathic hypertrophic cardiomyopathy - CORRECT ANSWER -systolic murmur loudest at the LLSB; LVOT obstruction + stiffened, noncompliant left ventricle (impairs filling during diastole = decreases CO --> more pronounced with tachycardia due to decreased filling time) -decrease preload (decreased venous return) or decrease afterload = accentuate murmur --> strain against closed glottis -increase preload or increase afterload = quiet murmur --> supine with legs elevated -medications used to reduce pulse and increase diastolic filling time = beta blockers, non-DHP CCB" "Carcinoid syndrome - CORRECT ANSWER -results from production of high concentrations of serotonin by a carcinoid tumor --> leads to weight loss, flushing, diarrhea, bronchospasm, right sided cardiac valvular disease (tricuspid valve) -carcinoid tumors = neuroendocrine cell neoplasms; most common in small intestine (can also see in lung)" "Senile (actinic) purpura - CORRECT ANSWER benign patches of extravasated RBCs which occur on sun-exposed areas in elderly due to atrophy of dermal collagen from age and actinic (sun-related) damage --> cause dermal vessels to become fragile and break easily most common locations = dorsal hands and forearms platelet count normal no treatment necessary" "Hereditary Hemorrhagic Telangiectasia - CORRECT ANSWER -aka Osler-Weber-Rendu syndrome; inherited (autosomal dominant) blood vessel disorder -mucocutaneous telangiectasias on lips, oral mucosa, finger tips -AV malformations in brain, lungs, liver, and intestine --> significant morbidity due to bleeding -iron deficiency anemia caused by occult bleeding"