NBME practice exam #1 Questions Answered 100% correct 2023

NBME practice exam #1 Questions Answered 100% correct 2023 Mitotic cyclin synthesis G2 phase Vitamin E def anemia Hemolytic anemia~ red antioxidants vs B12 def (megaloblastic macrocytic anemia) Hemolysis~ dec Hgb/hematocrit, inc LDH (normal MCV), and neurologic symptoms vs B12 def: dec Hgb/hematocrit, inc MCV, and neurologic symptoms (dorsal column) Volume of distribution Vd = (amount of drug in the body) / (plasma drug concentration) Achondroplasia Endochondrial ossification dysfunction (inhibit chondrocyte proliferation) TGF beta over expression Fibroblast growth factor ~ keloid and hypertrophic scar development Thyroglossal duct cyst a palpable cystic midline mass (fill w/mucous) in the neck sub>supra hyoid bone ~incomplete closure of the thyroglossal duct lined by lymphoid and mucous cells Connects tongue to thyroid gland developing: originates from tongue tissue Doesn't close completely-> cyst (fill w/mucous) -enlarge in infections, inc mucous, form thyroid cancer via ectopic thyroid tissue Moves w/tongue mvmt Immunoreactive trypsinogen (IRT) Measurement in blood of newborn babies is an assay in rapidly increasing use as a screening test for cystic fibrosis Positive~ CF (2 mutations- AR to cause CF phenotype) Mullerian agenesis (Mayer-Rokitansky-Kuster-Hauser syndrome) vs androgen insensitivity Both present w/blind vaginal pouch and absent 1st menstrual period AI: XY w/absent hair development (inc tesoterone-> estrogen production and female characteristics) MIF still made in embryo, also may be very tall~ lack of androgen mediated growth plate closure MA: XX w/NORMAL hair development suspensory ligament of ovary Ligament that contains ovarian vessels -posterior to ligament~ ureter Oophorectomy: divides suspensory ligament~ risk of ovarian vessel of ureter damage Ureter: also runs behind the uterine artery (F) and vas deferens (M) near its entrance to the bladder delirium tremens (DTs) the dramatic physical and psychological effects of alcohol withdrawal -> autonomic instability~ hypokalemia (catecholamine mediated intracellular shifts of K+ via inc Na/K+ ATPase activity)-> arrythmias Beneficence weighing risks and costs of procedure against the benefits of treat ment vs nonmaleficence: avoiding the causation of harm Zellweger syndrome Peroxisomal disease can't metabolize very long chain FA (VLCFAs) or branched-chain FAs (e.g. phytanic acid, via alpha-oxidation) Serum: high bilirubin, AST/ALT and VLFAs** Can't form myelin in CNS. Hypotonia, seizures, hepatomegaly, jaundice, MR, facial defects-look like jimmy neutron Myositis ossificans a condition in which bone forms in and replaces muscle tissue~Ca deposition as a result of trauma Radiation therapy treatment of cancer with a radioactive substance, x-ray, or radiation~ Free radical (OH-) formation ~ Xray or gamma Obstructive sleep apnea inc BMI, progressive/chronic daytime sleepiness and fatigue -awakes in the middle of the night: hypoxemia and hypercapnia ~ resp depression Complications: Peripheral edema and loud S2 ~ systemic HTN (sympathetic overstimulation when O2 drops too low) leading to vasoconstriction and inc HR Pulmonary HTN~ RHF (transient hypoxemia at night) vs central SA: loss of resp drive Peptide transporter (TAP) MHC Class I+ endogenous antigen ~ transporter associated w/antigen processing (TAP processing) vs MHC class II + invariant chain~ acidified endosome HLA D HLA A-C~ 1 letter ~ MHC Class I vs HLA DP, Q, R~ 2 letters ~ MHC Classs II Evolution of MI dark --> red --> yellow --> white 1 day: Coagulative necrosis~ neutrophils, wavy fibers w/o nuclei (reperfusion injury) 1-3 day: inc neutrophils and extent of coagulative necorsis 3day -2 weeks: granulation tissue: yellow/pale, lots of vasculature and macrophages 1 month: fibrous tissue (less vasculature) contracted scar (HF, aneurysms, mural thrombus, and dressler's syndrome) Fibromuscular dysplasia Most commonly affects renal artery and carotid artery~ 2nd most common cause of renal artery stenosis (1st = atherosclerosis-older age) Child bearing age, women Hydronephrosis post renal failure-> inc hydrostatic pressure builds back up into tubule system and into Bowman's space (inc pressure eventually pushes against the FORCE DRIVING GFR) This destroy filtration fx and causes renal failure Protein digestion in GI stomach: acid denatures and “opens up” proteins + pepsin (nonspecific cleavage) duodenum: pancreatic enzyme site of action then cleave denatured polypeptides into smaller bits; SI-intestinal mucosa: brush border enzymes finally break down into di/tri-peptides into absorbable amino acids Dorsolateral medulla stroke PICA lesion Lesion here: Lateral: CL sensation/pain/temp loss in body (motor runs medial) IL sensation/temp loss of face (CNV is lateral- not a factor of 12) Loss of gag reflex/paralysis of vocal cord: CN 9-10~ medulla (1-4 midbrain, 5-8 pons, 9-12 medulla) Acral lentiginous melanoma palms, soles, under nails; may occur in blacks Acral- palms and soles Mammography x-ray imaging of the breast~ AGE 40 and up 30-40~ wt bearing and regular exercise~ dec risk of osteoporosis Monosodium vs calcium pyrophosphate dihydrate crystals Monosodium=gout (needle shaped) Calcium pyrophosphate dihydrate=pseudogout (rhomboid shaped) macrocytic anemia A form of anemia characterized by large, immature red blood cells compare size to lymphocyte nucleus (should be same size) B12 def~ megaloblasts as well (not in picture) Megaloblastic: B12/Folate def, fanconi anemia, oriotic aciduria vs no megaloblasts: Liver dz, alcoholism and diamond blackfan anemia Depression w/cardiac issues can't give tricyclics (arrhythmic SEs) TCAs 1st line in depression: SSRI/SNRIs: paroxetine, citalopram, sertraline, fluoxetine/duloxetine, venlafaxine 11β-hydroxysteroid dehydrogenase Converts Cortisol-> cortisone in renal tubule (prevents GC to have MC effects at Aldosterone receptor) Overwhelming inc in cortisol or inhibition of 11bHS-DH~ hypokalemic HTN (inc GC~ inc MC action) Puberty associated gynecomastia Typically resolve in 12-18 months TMJ syndrome dysfunction of the temporomandibular joint (TMJ) Elevation of mandible: Lateral pterygoid ~ depression of mandible for opening Rectoceles a prolapse of the wall between the rectum and the vagina~ diverticulosis and damage to rectovaginal septum splinting: Push/support prolapsed rectum in vagina back into rectum during pooping Gonadotropins (FSH and LH) FSH stimulates the sertoli cells, which line the seminiferous tubules, produce spermatocytes (and inhibin A for - feedback) LH stimulates Leydig cells to make testosterone~ systemic effects and local sertoli cell/spermatozoa support Clomiphene citrate Medication used to induce ovulation: SERM treats infertility in women who don't ovulate: polycystic ovary syndrome ~ inc GnRH stimulation at hypothalamus -> gonadotropins from pituitary CFTR-F508del miss-folded protein made and can't fx so not sent to transmembrane ACCUMULATES IN RER Glycerol and fructose vs galactose entry to gluconeogenesis fructose bisphosphatase deficiency: looks exactly like Von Gierke's (hypotonia, hepatomegaly, hypoglycemia, lactic acidosis, ketonemia) Both ~ GNG dysfx (VG~ GNG and glycogen breakdown dysfx- G6P'tase def) IV glycerol or fructose doesn’t help because both enter the gluconeogenesis pathway below fructose bisphophatase at Glyceraldehyde 3P Galactose** enters above Fructose Biphos'tase transferred to G6P Wrist bones Straight Line Tuh Pinky, Here Comes The Thumb Scaphoid, Lunate, Triquetrium, Pisiform Hamate, Capitate, Trapezoid, Trapezium FOOSH injury: scaphoid is most common one to be fractured, lunate is most common to be dislocated case series study Study in which information about individual patients who share a disease in common is gathered over time Asthma exacerbation smoking is the #1 cause Inflammatory edema/exudate burns, anaphylaxis or sepsis, intercellular contacts disintegrate in post-capillary venules leading to intercellular gap formation-> release of contents arterioles vasodilate-> flushing venules expand (gaps)-> edema and swelling/blister formation Gaussian Distribution (normal distribution) Tetradotoxin (TTX) marine bacteria in Japanese puffer fish - binds to outside of Na channels and blocks sodium entry - impairs impulse conduction~ blocks cardiac contraction and nerve stimulation (cardiac arrest and paralysis) T1DM inheritance pattern Multifactorial ~ HLA-DR3 and 4 Synaptobrevin (VAMP) SNARE protein Synaptobrevin is the target of tetanospasmin (tetanus toxin) Tetanus toxin~ prevents GABA/Glycine neurons (traveling retrograde) to cause over activation of mucles-> myoclonus and spasms Intraductal papilloma The most common cause of bloody nipple discharge. Parotid duct passageway for delivering saliva from parotid gland into mouth passes through buccinator Elderly patients with caregivers Always be weary of abuse, speak to patient in private without caregiver when possible or disclosing diagnosis Biliary colic pain in the gallbladder caused by gallstones obstructing bile flow exocrine pancreas, gallbladder, and liver: the epithelium lining biliary tract has alkaline phosphatase so when they are damaged it releases this, increasing serum alk phos alkphos and bilirubin [conjugated] inc>ALT/AST inc ~ cholandrocyte damage ALT/AST inc> bilirubin [unconjugated]/alkphos~ hepatocyte damage Motorcycle collsion~ dysmetric on right Dysmetria: inaccurate hand mvmts (over and under shooting) A- primary motor cortex = wrong side of body (deficit of UMN on left side body) B - Thalamus = sensory information conduit - motor deficits unlikely to originate from here C - Pons - CNs 8,7,6,5, likely result in "locked in syndrome" or complete loss of motor function on right side + facial features. D. Vermis - central body coordination. Damage~truncal ataxia E. Cerebellum, posterior lobe~ peripheral ataxia Osteogenesis imperfecta wound healing brittle bone dz ~ bruising/poor wound healing, blue sclerae and fractures RER~ dysfx glycosylization Wound repair: granulation tissue~ type 3 collagen -> type 1 collagen during scar formation (defect in Type 1 collagen formation) Lamin vs Laminin Fibronectin is an ECM glycoprotein lamin is an intermediate filament ~ support to the cell nucleus. Don’t confuse lamin with laminin laminin is like fibronectin, an ECM glycoprotein~ basal lamina in BMs Enveloped virus enveloped virus don't hold up to acid, heat or being dried. fever and a cough, while affecting the larynx. ~ coronavirus (causes SARS/MERS (not EBV-no cough) Heme synthesis d-ALA synthase RLS: glycine and succinyl CoA -> delta-ALA -dysfx~ microcytic sideroblastic anemias earlier dysfx: higher up~ higher up symptosm (psych symptoms + port wine colored urine)= acute intermittent poryphyria~ CYP45- inducers -> inc liver fx and inc heme synthesis Later~ skin symptoms poryphyria cutanea tarda (vamparism)~HCV Prolonged bed rest supine position for a long time ~ increased venous return which leads to increased CO -> dec RAAS and inc ANP (RA), leading to decreased aldosterone-> increased diuresis which leads to decreased BV don't confuse with supine hypotension: IVC compression-> dec venous return due to compression~ pregnancy drug trial phases SWIM Phase 1 - small number of volunteers assess for Safety Phase 2 - moderate number of patients, does it Work Phase 3 - large number random assignment, with placebo, any Improvement? Phase 4 - hit the market, any unexpected side effects, can be withdrawn from Market Male onset of puberty nocturnal LH pulses ~ inc in FSH~ sperm and LH~ testosterone effects (2nd sex characteristics, growth, muscle) Paroxysmal nocturnal hemoglobinuria Red urine in the morning, fragile RBCs~ defect in cell membrane anchor protein~ anti-MAC (complement) on RBCs Tx: Eculizumab HOX genes Hox genes come from a family of homeobox genes that encode transcription factors~development to correctly form body part syndactyly, polydactyly, an extra cervical rib, and an increased risk of cancer. Vit A~ teratogen impacts HOX gene fx Cuff arterial occlusion and ADP function cuff is tied, the cells and tissue distal to the cuff will continue consuming ATP (ATP->ADP), but no fresh blood will be delivered to “clear” what will be an accumulating ADP and other metabolites. ADP (=Adenosine) is itself a proxy of consumption and drives vasoDilation of arteries Increasing ADP/Adenosine in a “local environment” is a signal to the body that a lot of consumption is occurring there; thus, arteries and arterioles naturally dilate to increase blood flow rates and “sweep away” metabolic byproducts Statins MOA Inhibit HMG CoA reductase; cholesterol precursor=mevalonate inc LDL R synthesis on the surface of the liver (inc LDL uptake) Plasmodium vivax/ovale ring form, an early ameboid trophozoite with co-existing Schuffner stippling and a mature schizont can be seen in one field ~hypnozoite formation in liver cellls Organic Acid Metabolism Disorders Ornithine Transcarbamylase def: hyperammonemia (not present in oriotic aciduria), acidemia (oriotic acid builds up~ pyrimidine synth not present w/Carbamoyl Synth I def), hypotonia, decreased reflexes Maculae adherens (desmosomes) ~stratum spinosum= suprabasal keratinocyte (above stratum basalis) vegitative state Lacks corical activity but BS fx remains Directives: what pt would want in this state (follow orders; no attempt to resuscitate) Penile Stimulation penile stimulation leads to an erection. This reflex only needs an intact arc in S2-S4 Psychogenic stimulation~ Cortex and association Cardiac tamponade Beck's triad: distant heart sounds, pulsus paridoxus and distended neck veins (plus likely hypotension) Autoregulation of GFR vs Endocrine Autoregulation~ local changes in BP Maintains GFR despite changes in local blood pressure and blood flow By changing diameters of afferent arterioles, efferent arterioles, and glomerular capillaries Myogenic: afferent arteriole~ inc RBF-> reactive vasoconstriction (inc ca release from SM cells)-> DEC RBF/GFR Tubuloglomerular feedback: inc RBF~ inc GFR-> inc Na/Cl delivery to JGA (in DCT)-> vasoconstrict afferent arteriole and DEC RBF/GFR Endocrine~ more systemic changes in BP AngII (inc Na/H activity-(inc Na HCO3 absorb); constrict efferent arteriole-> inc GFR) and inc aldosterone (inc Na and H+/K+ excretion~ contraction alkalosis) ANP: ~ inc naturesis via Afferent arteriole dilation and dec Na reabsorb in DCT Prostaglandins: PGE~ afferent arteriole dilation ~ inc GFR (NSAIDs reduce GFR~ inc risk of renal injury/insufficiency) Dual blood supply to testes Artery of ductus deferens (from sup vesicular~ internal iliac) and testicular arteries (from aorta) Vibrio parahaemolyticus gastroenteritis~ raw oysters (vomit and diarrhea) communicating hydrocephalus hydrocephalus ~impaired absorption arachnoid granulation CSF flow; whole CSF system would have increased pressure-> widened subarachnoid space Eti: scarring from meningitis or previous brain surgery (repair berry aneurysm in COW) -sub types: communicating= scarred arachnoid granulations (+papilledema) normal pressure: wet wobbly wacky~ older ppl, ventricular expansion w/urinary incontinence triad: gait apraxia (normal muscles but struggle w/intended fx), urinary incontinence and cognitive dysfx (old dude, comes in peeing himself and w/neuromuscular symptoms + hydrocephalus that is unexplained) Non communicating hydrocephalus hydrocephalus caused by a something obstructing the normal flow of CSF; Caused by stenosis of aqueduct of sylvian, colloid cyst blocking foramen of monro or a tumor (often pediatric~ infratentorial: Pinealoma, ependyoma, medulloblastoma) glue sniffer rash inhalant abuse around the nose and mouth is sometimes seen after prolonged use may look like impetigo; rapid improvement upon lack of use~ quick half life (differ from alcohol/benzos)~ other CNS depressants injection of conjuntivae: redness and friable or inflammed tissue Alendronate Bisphosphonate (-dronate ~ donate) ~ osteoporosis treatment Can cause esophagitis Prosopagnosia (face blindness) an inability to recognize faces, which may result from damage to the inferior temporal lobe encompassing the fusiform face area~ PCA stroke Post-stent complications Both~ coronary syndrome or angina Stent thrombosis= acute occlusion of a coronary artery stent, which often results in acute coronary syndrome: prevent w/dual antiplatelet therapy or drug-eluting stents. Re-stenosis is chronic narrowing of the stent lumen due to neointimal proliferation, resulting in anginal symptoms progressing overtime portal-caval anastomoses Umbilicus: caput medusa Distal esophagus: esophageal varices Rectum/anus: hemorrhoids rectum and anus, where the superior rectal vein (from the portal system) meets up with the middle and inferior rectal veins (which drain to the caval system) CD18 deficiency immunodeficiency looks like GC use: CD18=integrens~ leukocyte migration LADI (leukocyte adhesion deficiency), margination (leukocyte unable to travel to site of infect) => necrotic infects, and inc leukocyte count in BS (like GCs action) Tx = BMT, gene therapy HNPCC vs FAP mutation FAP (due to mutation in APC gene- F-APC, which is a tumor suppressor gene-> 2 hit hypothesis -> tons of polyps -> inc risk GI cancer Lynch syndrome (MarSHawn Lynch) AKA hereditary non-polyposis colorectal carcinoma (HNPCC), caused by a mutation in a number DNA mismatch repair genes~ microsatellite instability (MHS2-MicroSatellite/MLH1) Muscle stretch reflex Afferent: stimulus / somatosensory neurons (DRG), form an excitatory synapse in spinal cord Efferent: response, lower motor neurons Both occur on same side in knee jerk reflex. BYPASS brain / cerebrum Sertoli-Leydig Tumors Young girls (teens to young adult) produce androgens -> virilization (excessive hair, deep voice) -> need to rule out adrenal tumors -> differentials are familial hirsutism, medications, PCOD vs fx of normal female gonadal cells: theca/granulosa cells: Theca (Le Thicc) ~ LH -> androstenedione via desmolase Granulosa (estroGAN) ~ FSH-> takes androstenedione-> estrone/estradiol via aromatase Trichonella spiralis nematode, from undercooked pig/bear meat symptoms- intestinal (diarrhea, abdominal pain, vomiting), muscle inflammation (lesions can calcify), life-threatening (myocarditis, CNS, pneumonitis), periorbital edema dx on muscle biopsy