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NBME 17 Answers

Block/Question (20.7 difficulty score)
An 80-year-old woman is being evaluated for ...
Additional testing to confirm the diagnosis of TAπŸ”

Block/Question (9.5 difficulty score)
A 55-year-old man with chronic bronchitis is ...
NaloxoneπŸ”

Block/Question (20.0 difficulty score)
A 6-week-old girl is brought to the physician ...
Immature lower esophageal sphincterπŸ”

Block/Question (10.6 difficulty score)
A 21-year-old man comes to the emergency ...
Inferior rectal veinπŸ”

Block/Question (14.8 difficulty score)
A 24-year-old man with a history of ...
480πŸ”

Block/Question (15.4 difficulty score)
A 42-year-old farmer has a 7-mm red scaly ...
Actinic keratosisπŸ”

Block/Question (17.5 difficulty score)
A 12-year-old boy is swimming in a mountain ...
Central blood volume: increased; ADH (vasopressin): decreased; Atrial natriuretic peptide: increasedπŸ”

Block/Question (8.1 difficulty score)
A 42-year-old woman comes to the physician ...
RosaceaπŸ”

Block/Question (6.8 difficulty score)
A newborn has male genital ducts but female ...
ScrotumπŸ”

Block/Question (9.2 difficulty score)
A 9-year-old girl is brought to the physician ...
Diverticulum of the roof of the embryonic oral cavityπŸ”

Block/Question (13.8 difficulty score)
A 28-year-old woman is brought to the ...
Area labeled with letter 'C'πŸ”

Block/Question (9.5 difficulty score)
A 56-year-old man comes to the physician 4 ...
Right subthalamicπŸ”

Block/Question (8.7 difficulty score)
An 80-year-old woman comes to the emergency ...
HydrochlorothiazideπŸ”

Block/Question (10.9 difficulty score)
A randomized clinical trial is conducted to ...
Neither procedure is superiorπŸ”

Block/Question (7.8 difficulty score)
A 13-year-old girl has a grade 2/6, ...
TricuspidπŸ”

Block/Question (10.8 difficulty score)
A 2-month-old boy is given a vaccine that has ...
Haemophilus influenzae type bπŸ”

Block/Question (13.2 difficulty score)
A 28-year-old woman at 18 weeks' gestation ...
Free T4πŸ”

Block/Question (5.8 difficulty score)
A 21-year-old man is brought to the emergency ...
Streptococcus pneumoniaeπŸ”

Block/Question (12.7 difficulty score)
A 38-year-old woman comes to the physician ...
Proliferative endometrial tissueπŸ”

Block/Question (10.3 difficulty score)
A 60-year-old man comes to the physician ...
Pleural effusionπŸ”

Block/Question (7.7 difficulty score)
A 65-year-old woman with ovarian cancer is ...
DNA replicationπŸ”

Block/Question (12.5 difficulty score)
In a clinical study, a polymorphic marker ...
2,3πŸ”

Block/Question (7.5 difficulty score)
A study is conducted to assess the ...
Placebo effectπŸ”

Block/Question (11.2 difficulty score)
A 40-year-old man is evaluated because his ...
Heme synthesisπŸ”

Block/Question (9.1 difficulty score)
A 40-year-old woman comes to the physician ...
SulfasalazineπŸ”

Respiratory
Block/Question (9.8 difficulty score)
A 40-year-old man with interstitial pulmonary ...
Increased radial traction on airwaysπŸ”

Block/Question (6.5 difficulty score)
An investigator wishes to conduct a study of ...
CohortπŸ”

Block/Question (9.2 difficulty score)
A 25-year-old woman comes to the physician ...
21-HydroxylaseπŸ”

Block/Question (7.5 difficulty score)
A 38-year-old man is brought to the emergency ...
Metabolic acidosisπŸ”

Block/Question (6.3 difficulty score)
A 3-year-old boy and his 5-year-old brother ...
Factor VIII (antihemophilic factor)πŸ”

Block/Question (7.7 difficulty score)
A 40-year-old African American woman comes to ...
1,25-DihydroxycholecalciferolπŸ”

Block/Question (7.7 difficulty score)
A 30-year-old woman who is at 20 weeks' ...
Tracheoesophageal atresiaπŸ”

Block/Question (7.4 difficulty score)
A 15-year-old girl is brought to the ...
First-degree burnπŸ”

Block/Question (6.8 difficulty score)
A 16-year-old boy is brought to the physician ...
Luteinizing hormoneπŸ”

Block/Question (12.0 difficulty score)
A 14-year-old boy is brought to the physician ...
Inhaled glueπŸ”

Block/Question (9.1 difficulty score)
A 65-year-old woman undergoes surgical repair ...
Area labeled with letter 'A'πŸ”

Block/Question (8.0 difficulty score)
A 10-year-old girl is brought to the ...
Breast bud developmentπŸ”

Block/Question (10.2 difficulty score)
A physician is sad because he has to inform a ...
Yes, it is.πŸ”

Block/Question (11.0 difficulty score)
A 34-year-old man is evaluated after becoming ...
Sympathetic efferent activity: increased; parasympathetic efferent activity: decreasedπŸ”

Block/Question (7.9 difficulty score)
A 44-year-old woman comes to the physician ...
Ubiquitin ligaseπŸ”

Block/Question (8.4 difficulty score)
A 75-year-old man comes to the physician ...
Increased hydrostatic pressure in Bowman spaceπŸ”

Block/Question (10.7 difficulty score)
A 20-year-old man is brought to the emergency ...
EpinephrineπŸ”

Block/Question (11.5 difficulty score)
A female newborn delivered at 36 weeks' ...
Incomplete formation of pleuroperitoneal membraneπŸ”

Block/Question (11.1 difficulty score)
An 18-year-old man with Crohn disease is ...
T-lymphocyte functionπŸ”

Block/Question (8.9 difficulty score)
A 4-year-old boy is brought to the physician ...
Congenital ureteral obstructionπŸ”

Block/Question (6.2 difficulty score)
Ten healthy human subjects are given a new ...
Phase 1πŸ”

Block/Question (5.0 difficulty score)
A 27-year-old woman is admitted to the ...
StruviteπŸ”

Block/Question (9.0 difficulty score)
A previously healthy 48-year-old nulligravid ...
Endometrial hyperplasiaπŸ”

Block/Question (8.7 difficulty score)
An 83-year-old man is brought to the ...
Early septic shockπŸ”

Block/Question (7.3 difficulty score)
A 46-year-old man is treated with oral ...
Suppressing the early response of T lymphocytes to activationπŸ”

Block/Question (5.4 difficulty score)
A 54-year-old woman with hypertension and ...
Vasodilating prostaglandins at the afferent arterioleπŸ”

Block/Question (7.2 difficulty score)
A 32-year-old woman, gravida 2, para 1, at 7 ...
Ectopic pregnancyπŸ”

Block/Question (11.1 difficulty score)
A 55-year-old man is admitted to the hospital ...
0.9% SalineπŸ”

Block/Question (16.3 difficulty score)
A 32-year-old man comes to the physician ...
Tissue: Testicle; Effect: Estradiol productionπŸ”

Block/Question (10.3 difficulty score)
A 45-year-old man comes to the physician ...
Mallory hyalineπŸ”

Block/Question (10.9 difficulty score)
A previously healthy 72-year-old man is ...
Gastrointestinal blood lossπŸ”

Block/Question (6.6 difficulty score)
A 20-year-old man with suspected appendicitis ...
T10πŸ”

Block/Question (7.3 difficulty score)
A 45-year-old man comes to the physician ...
Tumor necrosis factorπŸ”

Block/Question (8.1 difficulty score)
An otherwise asymptomatic 52-year-old woman ...
Failure of the ovaries to secrete 17Ξ²-estradiolπŸ”

Block/Question (7.8 difficulty score)
A 16-year-old girl comes to the physician ...
Dopamine Ξ²-hydroxylaseπŸ”

Block/Question (6.1 difficulty score)
A 41-year-old woman is evaluated because of ...
Fibromuscular dysplasiaπŸ”

Block/Question (6.1 difficulty score)
A 48-year-old man comes to the physician ...
Increased intestinal iron absorptionπŸ”

Block/Question (8.3 difficulty score)
A 10-year-old boy has had anemia since birth. ...
Hereditary spherocytosisπŸ”

Block/Question (5.8 difficulty score)
A 34-year-old patient with AIDS develops ...
MacrophagesπŸ”

Block/Question (8.1 difficulty score)
15-year-old, lesions on neck, acid-fast ...
Temperature SensitivityπŸ”

Block/Question (8.3 difficulty score)
60-year-old man progressive shortness of ...
Alveolar macrophageπŸ”

Block/Question (6.7 difficulty score)
22-year-old woman, gravida 1, para 1... ...
Internal iliacπŸ”

Block/Question (7.0 difficulty score)
A previously healthy 17-year-old girl is ...
MyoglobinπŸ”

Block/Question (5.6 difficulty score)
63-year-old man, 3-month history of ...
Increased capillary hydrostatic pressureπŸ”

Block/Question (4.7 difficulty score)
14-year-old boy is brought to the emergency ...
Maxillary division of the trigeminal nerveπŸ”

Block/Question (3.8 difficulty score)
50-year-old woman comes to the physician... ...
Inhibition of osteoclast-mediated bone resorptionπŸ”

Block/Question (4.8 difficulty score)
58-year-old man with supraventricular ...
The junction of the superior vena cava and the right atriumπŸ”

Block/Question (6.4 difficulty score)
6-mercaptopurine (6-MP) is used to treat ...
They must be given decreased doses of 6-MPπŸ”

Block/Question (7.7 difficulty score)
An 80-year-old man with Type 2 Diabetes ...
Pelvic SplanchnicπŸ”

Block/Question (6.2 difficulty score)
35-year-old woman has an abnormal Pap smear. ...
Neoplastic cells in the sub-basement membrane connective tissueπŸ”

Block/Question (9.5 difficulty score)
A 45-year-old woman comes to the physician ...
25%πŸ”

Block/Question (6.4 difficulty score)
A 56-year-old woman develops a restrictive ...
Beta-Pleated sheet structureπŸ”

Block/Question (5.8 difficulty score)
45-year-old man with poorly controlled type 2 ...
Enterococcus faecalisπŸ”

Block/Question (4.9 difficulty score)
An 81-year-old woman is admitted to the ...
Potentiates the action of antithrombin IIIπŸ”

Block/Question (3.8 difficulty score)
18-month-old girl is brought, separation of ...
Leukocyte adhesion and transmigrationπŸ”

Block/Question (6.4 difficulty score)
16-year-old girl comes to the physician ...
IgMπŸ”

Block/Question (6.4 difficulty score)
A 65-year-old woman with a 20-year history of ...
L-3 to 4πŸ”

Block/Question (4.2 difficulty score)
38-year-old man with a 3-year history of type ...
ContemplationπŸ”

Block/Question (6.2 difficulty score)
27-year-old woman comes to the physician... ...
Trophoblastic tissueπŸ”

Block/Question (6.9 difficulty score)
A new compound is taken up by bacterial ...
Carrier-mediated diffusionπŸ”

Block/Question (6.4 difficulty score)
1-week-old girl is brought...defect in fatty ...
Measurement of serum acylcarnitine concentrationsπŸ”

Block/Question (4.3 difficulty score)
A previously healthy 3-year-old boy is ...
Interleukin-8 (IL-8)πŸ”

Block/Question (5.5 difficulty score)
59-year-old comes to the physician... lack of ...
CerebellumπŸ”

Block/Question (3.7 difficulty score)
A 37-year-old man comes to the physician, diarrhea
Pseudomembranes of fibrin and inflammatory debrisπŸ”

Block/Question (5.3 difficulty score)
A 24-year-old man comes to the physician, ...
T-lymphocytesπŸ”

Block/Question (7.3 difficulty score)
The sequence surrounding the first two exons ...
Disruption of normal splicing by creation of a new 3' splice siteπŸ”

Block/Question (3.6 difficulty score)
A 52-year-old man is brought to the physician ...
PellagraπŸ”

Block/Question (4.4 difficulty score)
A 20-year-old man comes to the physician, ...
Posterior pituitary glandπŸ”

Block/Question (8.1 difficulty score)
A 30-year-old woman comes to the physician ...
KidneyπŸ”

Block/Question (4.4 difficulty score)
35-year-old man is brought to the ED, fatigue ...
Activation of adenylyl cyclaseπŸ”

Block/Question (7.8 difficulty score)
A female newborn is delivered at 38 weeks' ...
15 to 40πŸ”

Block/Question (7.4 difficulty score)
A 27-year-old primigravid woman at 34 weeks' ...
SchistocytesπŸ”

Block/Question (4.2 difficulty score)
A 30-year-old man is brought to the ED... CT ...
Middle meningeal arteryπŸ”

Block/Question (4.7 difficulty score)
An investigator is studying mechanisms of ...
Transforming growth factor-beta πŸ”

Block/Question (5.5 difficulty score)
A 63-year-old man comes to the physician ...
Calcified 80% stenosisπŸ”

Block/Question (6.5 difficulty score)
A 50-year-old man comes to the physician 3 ...
CalciumπŸ”

Block/Question (3.3 difficulty score)
A 68-year-old man comes to the physician... ...
Inhibition of phosphodiesterase πŸ”

Block/Question (4.2 difficulty score)
8-year-old boy is brought to the physician by ...
Increased release of dopamine and norepinephrineπŸ”

Block/Question (7.9 difficulty score)
A protein found in the brown adipose tissue ...
Increased ratio of oxygen consumption to ATP generationπŸ”

Block/Question (4.0 difficulty score)
A 36-year-old man undergoes elective ...
Decreases release of Ca2+ from the sarcoplasmic reticulumπŸ”

Block/Question (4.8 difficulty score)
A 60-year-old man who emigrated from China to ...
AflatoxinπŸ”

Block/Question (7.0 difficulty score)
A 29-year-old woman comes to the physician ...
Decreased thyroid stimulating hormone, decreased free thyroxine, increased free triiodothyronineπŸ”

Block/Question (4.4 difficulty score)
A 42-year-old man comes to the physician ...
Development of autoantibodies against desmosomal proteinsπŸ”

Block/Question (4.7 difficulty score)
A 38-year-old woman comes to the physician ...
VagusπŸ”

Block/Question (4.0 difficulty score)
A 20-year-old woman has multiple ...
Autosomal dominantπŸ”

Block/Question (5.0 difficulty score)
A 67-year-old man has urinary urgency after ...
Inhibition of muscarinic receptorsπŸ”

Block/Question (6.0 difficulty score)
A 50-year-old man who has smoked 2 packs of ...
Increased blood HCO3-πŸ”

Block/Question (4.2 difficulty score)
A 30-year-old primigravid woman at 22 weeks' ...
Listeria monocytogenesπŸ”

Block/Question (7.0 difficulty score)
A previously healthy 42-year-old man is ...
IL-1 and tumor necrosis factor (TNF)-alphaπŸ”

Block/Question (9.2 difficulty score)
A 56-year-old woman comes to the physician ...
Maintenance of the basement membrane integrityπŸ”

Block/Question (5.6 difficulty score)
In a nuclear transplantation experiment, ...
ImprintingπŸ”

Block/Question (5.3 difficulty score)
An 18-year-old woman develops sepsis after an ...
Decreased plasma fibrinogen concentrationπŸ”

Block/Question (3.7 difficulty score)
A 62-year-old woman with recurrent pulmonary ...
VII (proconvertin)πŸ”

Block/Question (10.1 difficulty score)
A 19-year-old man is admitted to the hospital ...
Left achilles tendonπŸ”

Block/Question (3.2 difficulty score)
60-year-old man comes to the physician ...
Parietal cellsπŸ”

Block/Question (6.9 difficulty score)
A 42-year-old woman comes to the physician ...
Cholesterol synthesisπŸ”

Block/Question (3.8 difficulty score)
A 45-year-old woman who is intubated and ...
Beta-glucan carbohydrates in the cell wallπŸ”

Block/Question (11.9 difficulty score)
A 58-year-old woman is brought to the ...
Membrane lipid peroxidationπŸ”

Block/Question (5.7 difficulty score)
A 3-year-old boy with sickle cell disease has ...
OsteomyelitisπŸ”

Block/Question (3.7 difficulty score)
A 59-year-old man undergoes a total ...
Decreased parathyroid hormone, decreased calciumπŸ”

Block/Question (4.0 difficulty score)
Ten years after total gastrectomy, a ...
B12 (cobalamin)πŸ”

Block/Question (4.0 difficulty score)
A 65-year-old woman comes to the physician ...
Lichen sclerosusπŸ”

Block/Question (3.4 difficulty score)
A 28-year-old woman comes to the physician ...
Parotid gland enlargementπŸ”

Block/Question (5.1 difficulty score)
A 75-year-old man comes to the emergency ...
Salicylate poisoningπŸ”

Block/Question (4.6 difficulty score)
A 55-year-old woman comes to the physician ...
Major Depressive DisorderπŸ”

Block/Question (4.8 difficulty score)
A 40-year-old woman with a 6-month history of ...
Wegener granulomatosisπŸ”

Block/Question (4.3 difficulty score)
A previously healthy 35-year-old man has ...
Family history of a similar illnessπŸ”

Block/Question (3.8 difficulty score)
A 25-year-old woman comes to the physician ...
Rheumatoid arthritisπŸ”

Block/Question (4.1 difficulty score)
A 65-year-old man who recently emigrated from ...
Trypanosoma cruziπŸ”

Block/Question (4.7 difficulty score)
A 53-year-old man, who recently returned from ...
MalariaπŸ”

Block/Question (5.6 difficulty score)
A 42-year-old man comes to the emergency ...
Infection with HIV-2πŸ”

Block/Question (2.8 difficulty score)
A 70-year-old man from China has a poorly ...
Epstein-Barr virusπŸ”

Block/Question (4.5 difficulty score)
Three days after unprotected sex with a new ...
Herpes Simplex Virus type 2πŸ”

Block/Question (5.4 difficulty score)
A 27-year-old woman comes to the physician ...
GonorrheaπŸ”

Block/Question (5.9 difficulty score)
A 28-year-old man is brought to the emergency ...
Dissecting aneurysmπŸ”

Block/Question (6.2 difficulty score)
A newborn delivered at 38 weeks' gestation ...
Congenital cytomegalovirus infectionπŸ”

Block/Question (11.0 difficulty score)
A 70-year-old man dies in a motor vehicle ...
Tubular adenomaπŸ”

Block/Question (4.1 difficulty score)
A 40-year-old woman comes to the physician ...
MelanomaπŸ”

Block/Question (6.0 difficulty score)
A 32-year-old man comes to the physician ...
X-rays of the sacroiliac jointsπŸ”

Block/Question (3.6 difficulty score)
A 28-year-old woman, gravida 1 para 1, comes ...
Staphylococcus aureusπŸ”

Block/Question (5.8 difficulty score)
A 60-year-old woman is brought to the ...
NephrolithiasisπŸ”

Block/Question (4.1 difficulty score)
A 62-year-old man dies suddenly while playing ...
Aortic stenosisπŸ”

Block/Question (4.1 difficulty score)
A 35-year-old man comes to the physician for ...
Dynein armsπŸ”

Block/Question (4.0 difficulty score)
A 57-year-old man with alcoholism has a ...
GynecomastiaπŸ”

Block/Question (4.5 difficulty score)
While lifting weights, a 24-year-old man ...
StrangulationπŸ”

Block/Question (4.3 difficulty score)
A 6-year-old boy who recently emigrated from ...
Vitamin EπŸ”

Block/Question (2.9 difficulty score)
A 63-year-old woman is brought to the ...
DeliriumπŸ”

Block/Question (4.2 difficulty score)
A 54-year-old woman comes to the physician 1 ...
MyxomaπŸ”

Block/Question (5.5 difficulty score)
A 48-year-old woman comes to the physician ...
Decreased plasma renin activityπŸ”

Block/Question (4.8 difficulty score)
A 70-year old man is admitted to the hospital ...
Pulmonary neoplasmπŸ”

Block/Question (3.2 difficulty score)
A 27-year-old man comes to the physician for ...
SchizoidπŸ”

Block/Question (5.3 difficulty score)
A girl is brought to the physician for a ...
9 πŸ”

Block/Question (7.6 difficulty score)
A 55-year-old woman has left flank pain and ...
Renal cell adenocarcinomaπŸ”

Block/Question (3.9 difficulty score)
A 35-year-old man comes to the physician ...
Influenza virusπŸ”

Block/Question (6.8 difficulty score)
A 60-year-old man comes to the emergency ...
Mesenteric venous thrombosisπŸ”

Block/Question (4.6 difficulty score)
A 6-year old boy has had three systemic ...
Total hemolytic complement concentrationπŸ”

Block/Question (4.4 difficulty score)
A 62-year-old man develops a pericardial ...
Fibrinous pericarditisπŸ”

Block/Question (8.6 difficulty score)
A 50-year-old man comes to the physician ...
OmeprazoleπŸ”

Block/Question (3.8 difficulty score)
A 34-year-old woman with pyelonephritis has ...
GentamicinπŸ”

Block/Question (3.2 difficulty score)
A 15-year-old girl comes to the physician's ...
Use of sunscreen by her peersπŸ”

Block/Question (3.8 difficulty score)
A 41-year-old man with asthma and an allergy ...
AlbuterolπŸ”

Block/Question (5.5 difficulty score)
A 38-year-old man comes to the physician ...
LoratadineπŸ”

Block/Question (3.5 difficulty score)
A 64-year-old man is brought to the emergency ...
Torsades de pointesπŸ”

Block/Question (3.5 difficulty score)
A 68-year-old woman with recent onset of type ...
LisinoprilπŸ”

Block/Question (3.5 difficulty score)
A 17-year-old boy comes to the physician ...
"Yes, your weight gain can be caused by genes and environment combined"πŸ”

Block/Question (2.5 difficulty score)
A 66-year-old man with stage IV colon cancer ...
LoperamideπŸ”

Block/Question (6.8 difficulty score)
A 62-year-old man with alcohol induced liver ...
SpironolactoneπŸ”

Block/Question (4.9 difficulty score)
A 26-year-old-woman comes to the physician 5 weeks
SertralineπŸ”

Block/Question (3.2 difficulty score)
A 60-year-old woman with a 3-year history of ...
EzetimibeπŸ”

Block/Question (4.6 difficulty score)
A 45-year-old woman who is a farmer is ...
DoxycyclineπŸ”

Block/Question (2.7 difficulty score)
A study is designed to evaluate the efficacy ...
Randomized clinical trialπŸ”

Block/Question (5.4 difficulty score)
A randomized controlled study of 2000 ...
Failure to distinguish between statistical significance and clinical significanceπŸ”

Block/Question (5.3 difficulty score)
In an epidemiologic study of workers in the ...
3 πŸ”

Block/Question (2.8 difficulty score)
In a survey of 100 households (average three ...
15%πŸ”

Block/Question (2.7 difficulty score)
An examination is scaled so that the scores ...
67%πŸ”

Block/Question (8.3 difficulty score)
A male newborn has macrocephaly with poor ...
CollagenπŸ”

Block/Question (7.7 difficulty score)
A 27-year-old woman is brought to the ...
Inferior alveolar nerveπŸ”

Block/Question (3.0 difficulty score)
A 30-year-old woman has ptosis, ...
ThymomaπŸ”

Block/Question (3.9 difficulty score)
A 45-year-old woman has a thyroidectomy ...
CalcitoninπŸ”

Block/Question (3.8 difficulty score)
A 79-year-old man is brought to the emergency ...
Insertion of transvenous pacemakerπŸ”

Block/Question (10.5 difficulty score)
An 18-year-old man has yellow nodules on the ...
Absence of functional LDL receptors in hepatocytesπŸ”

Block/Question (3.2 difficulty score)
A 68-year-old man comes to the physician ...
Left atriumπŸ”

Block/Question (6.1 difficulty score)
A healthy 70-year-old woman has participated ...
Residual volume: ↑; Arterial PO2: ↓; Alveolar-arterial PO2 difference: β†‘πŸ”

Block/Question (4.2 difficulty score)
A 20-year-old woman comes to the physician ...
Mannose-binding (type I) fimbriaπŸ”

Block/Question (7.1 difficulty score)
A 60-year-old man comes to the physician for ...
Surface kappa:surface lambda ratioπŸ”

Block/Question (3.4 difficulty score)
A 6-year-old girl is brought to the physician ...
PoxvirusπŸ”

Block/Question (9.4 difficulty score)
A 69-year-old woman comes to the physician ...
Area marked "G"πŸ”

Block/Question (7.9 difficulty score)
A male newborn is born at 28 weeks' ...
Area marked "D"πŸ”

Block/Question (2.8 difficulty score)
A pharmaceutical company is trying to develop ...
LeptinπŸ”

Block/Question (3.6 difficulty score)
A 68-year-old man is asked to give informed ...
Information, competence, voluntarinessπŸ”

Block/Question (2.1 difficulty score)
A 35-year-old man who uses crack cocaine ...
Admit the patient to the hospital for possible myocardial ischemia πŸ”

Block/Question (1.4 difficulty score)
A 24-year old man comes to the physician ...
T lymphocytes πŸ”

Block/Question (1.0 difficulty score)
A 43-year-old man comes to the physician for ...
"I'm sorry I got delayed. I hope I haven't made you late somewhere else."πŸ”

Recent comments ...

... cassdawg made a comment on nbme17/block0/q#0 (A 58-year-old woman is brought to the emergency...)
 +24 
submitted by cassdawg(924)

I don't like how they are asking this, but I think what they are getting at is that after the stent placement ("subsequent to the stent placement") there will be reperfusion injury to the myocardial tissue which occurs through free radical injury and therefore membrane lipid peroxidation is the best answer (FA2020 p210 mentions membrane lipid peroxidation as a mechansism of free radical damage and lists reperfusion injury after thrombolytic therapy as a type). Elevations in the cardiac enzymes I assume are because of the injury to the cells.

zalzale96  Created an account just to up vote this answer +4
cheesetouch  1998 journal via google " Myocardial injury after cardiac surgery with cardiopulmonary bypass may be related to free oxygen radical-induced lipid peroxidation" +
peteandplop  "Evidence suggests that reactive oxygen species (ROS) may play important roles in the pathogenesis in myocardial infarction [2]. Following ischemia, ROS are produced during reperfusion phase [3, 4]. ROS are capable of reacting with unsaturated lipids and of initiating the self-perpetuating chain reactions of lipid peroxidation in the membranes" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2274989/) +1
mittelschmerz  Honestly the wording got me on this one. Great answer +
acerj  Also, you can rule out a few of the options to help justify this. Post MI you expect necrosis, not apoptosis. Remember, apoptosis is suicide, and necrosis is MURDER! Cell swelling is a sign of cellular injury, not cell shrinkage. The heart will undergo coagulative necrosis, not liquefactive necrosis. Also, protease inactivation by cytoplasmic free calcium is kind of nonsensical to me. Free calcium is more likely to cause cell injury via caspases (a form of proteases amongst other things), which is why calcium is usually bound up inside healthy cells. +2
ownersucks  This question presentation is exactly how Sattar said in pathoma Ch2. Raise in cardiac enzyme following reperfusion +
... cassdawg made a comment on nbme17/block4/q#1 (83 yo man found bedridden and confused)
 +13 
submitted by cassdawg(924)

DISTRIBUTIVE SHOCK (I.E. SEPTIC OR ANAPHYLAXIS) ARE THE ONLY SHOCKS WITH INCREASED CARDIAC OUTPUT!

FA2020 p310

This man presents with hypothermia (septic shock can present with hyper or hypothermia), tachycardia, and low blood pressure with increased cardiac output, characteristic of septic shock. Further distributive shock is associated with severe decrease in systemic vascular resistance while other forms of shock have increased systemic vascular resistance.

cheesetouch  FA2018 P305 Shock +
... cassdawg made a comment on nbme17/block1/q#21 (42 yo farmer, 7 mm red scaly plaque on ear)
 +12 
submitted by cassdawg(924)

Just to add to the explanation here is what you would see in the others (most on FA2020 p484)

  • Basal cell carcinoma:
  • Keratoacanthoma:
    • Resembles squamous cell carcinoma in that it is a rapidly growing dome shaped nodule with a keratin filled center
    • On histology it basically presents as a crater filled with keratin
    

  • Malignant melanoma:
    • Bad boi, look for the ABCDEs (asymmetry, border irregularity, color variation, diameter >6mm, and evolution)
    • On histology you see melanocyte proliferation below the basement membrane and it just looks uglier
    

  • Merkel cell carcinoma:
kstebbins  ^Amazing with the links. Thank you! +3
... cassdawg made a comment on nbme17/block2/q#12 (2 month old boy given vaccine which converts T-independent antigens to T-dependent forms)
 +12 
submitted by cassdawg(924)

The question stem is referring to a conjugate vaccine. This is because conjugate vaccines convert T-independent antigens (polysaccharides) into T-dependent antigens by conjugating them with a protein. [FA2020 p127]

Remember that in order for a T-cell to be able to respond to an antigen via MHC, it MUST be a protein. Thus, T-dependent (dependent on T-cells) responses are to proteins. T-dependent responses are overall better because then B-cells can then undergo affinity maturation and class switching through interaction with T-cells. So, by conjugating bacterial polysaccharides to proteins, the immune response will be a more robust T-dependent reaction and will yield better protection. [FA2020 p103]

Conjugate vaccines exist for encapsulated bacteria (as the capsules are polysaccharide and would need to be conjugated to protein to improve response). These are Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae

You can remember these encapsulated organisms and their conjugate vaccine because they are THE SAME organisms that you become susceptible to when you have a splenectomy and which necessitate vaccination.

drippinranch  I appreciate this explanation so much. Thank you. +4
j44n  cassdawg you are a beast +1
... cassdawg made a comment on nbme17/block3/q#31 (20 yo man, 6 hours of difficulty breathing and vomitting)
 +11 
submitted by cassdawg(924)

Hormone sensitive lipase (HSL) is the enzyme which degrades triglycerides stored within adipocytes (FA2020 p93). Thus, it makes sense that it is activated in times of fasting and suppressed in the fed state.

Insulin would inhibit HSL, as insulin is a fed state enzyme secreted by the pancreas and would want to trigger storage of triglycerides.

In contrast glucagon is secreted in response to hypoglycemia by the pancreas and will trigger fasted state activation. In terms of the fed/fast state I always think of glucagon and epinephrine kind of like a superhero and their side kick, because they usually work together in the fasting state on similar targets to ensure the body has enough energy (this helps me remember that epinephrine and glucagon are fasting state hormones). Here though is epinephrine's big action away from glucagon, where glucagon has minimal effect and epinephrine has the big action of activating HSL! Glucagon has a minor role and other catecholamines and ACTH can also serve to activate HSL as well.

Another example of the synergistic work of glucagon and epinephrine is in glycogen breakdown (FA2020 p85). Both will trigger cAMP increase and protein kinase A activation which will phosphorylate glycogen phosphporylase and activate it (FAST PHOSPHORYLATE! Hormone sensitive lipase is actually phsophorylated to activate it as well).

FUN FACT: Hormone sensitive lipase actually got its name because it was sensitive to epinephrine!

flapjacks  In Type 1 DM, the glucagon response to hypoglycemia is not functional and these individuals are reliant on the epinephrine-stimulated hepatic glycogenolysis. I recall this by remembering you can administer glucagon to these patients if they're having a hypoglycemic episode. They can respond to it, but they aren't releasing it. +1
passplease  How did you eliminate thyroxine? As it also plays a role in lipolysis. I was thrown off my the low blood pressure and therefore did not select epinephrine. Why would they still have a low blood pressure? +
jackie_chan  ^ they have low blood pressure because DKA causes a lot of dehydration (vomiting, diuresis due to osmotically active glucose in urine) so low BP Thyroxine I eliminated because remember that thyroxine is unique in that it functions similar to a steroid hormone and acts in the nucleus to upregulate expression of many genes. I figured hormone-sensitive lipase needs to be activated, not stimulated to upregulate expression, so I thought about EPI and beta-3 stimulation. fuckPeter +
schep  I figured since he has low BP/dehydrated, his body would try to maintain cardiac output by increasing sympathetic tone (releasing epinephrine). In hypovolemic shock, systemic vascular resistance is up because of this compensation. +
j44n  also thyroxine works like a steroid hormone meaning it takes a while to cause its effect +
... cassdawg made a comment on nbme17/block4/q#14 (55 yo man, admitted to hospital for treatment of sepsis)
 +10 
submitted by cassdawg(924)

This has to do with the algorithm of treating shock. Septic (a type of distributive) shock as well as hypovolemic shock are treated with IV fluid resuscitation (FA2020 p310). Crystalloid fluids are first-line choice, and normal saline (0.9%, isotonic) is first-line specifically in cases of shock.

5% dextrose in water and 0.45% saline is hypertonic and not useful here.

5% dextrose alone is isotonic in the bag but physiologically hypotonic. It is more often given for fluid replacement after severe dehydration.

0.45% saline only is hypotonic and not useful here.

3% saline is hypertonic and not useful here.

... waitingonprometric made a comment on nbme17/block0/q#0 (A 70-year-old man dies in a motor vehicle collision....)
 +10 
submitted by waitingonprometric(137)

From FA2020, pg. 381:

Tubular adenoma--> neoplastic; tubular histology has less malignant potential than villous; tubulovillous has intermediate malignant potential; usually asymptomatic, may present with rectal bleeding. Hence our patient who has been undergoing evaluation for fecal occult blood.

Other answers:

Hyperplastic polyp--> most common, generally smaller and in rectosigmoid region. I'm guessing the picture attached to this question is trying to clue us into this not being a small lesion.

Inflammatory pseudopolyps--> due to mucosal erosion in inflammatory bowel disease. There is no appreciable erosions in this picture, also the mass appears pedunculated, so we know it's not a spot of normal mucosa that just looks raised compared to surrounding erosion.

Juvenile polyp and Peutz-Jeghers syndrome--> these are both genetic disorders with numerous hamartomatous polyps seen in the colon. Peutz-Jeghers also associated with increased risk of breast and other GI cancers. It is unlikely that our patient had either of these b/c he is 70 y/o; therefore, if he had one of these, he would likely have more than one colon lesion and may also present with a history of other cancers at his age.

cheesetouch  great refutation of others, thanks! +1
lpp06  To add - tubular adenomas are pedunculate masses, as seen in the image +2
soccerfan23  great explanation and username lol +
... cassdawg made a comment on nbme17/block4/q#37 (An 18-year-old man has yellow nodules on the...)
 +10 
submitted by cassdawg(924)

Yellow nodules (cholesterol deposits) on the achilles tendons have a very high association with Type II familial dyslipidemia, or familial hypercholesterolemia. This is caused most often by a defect in the LDL receptor function. (FA2020 p94)

cassdawg  NOTE: This patient shows a SELECTIVE increase in LDL so it is a defect in the LDL receptor NOT a defect in ApoB100. A defect in ApoB100 would present with increased VLDL as well! +14
ginachipotle  Note that the answer is ABSENT LDL receptors vs. partial reduction b/c LDL >700 (LDL = 980), indicating individual is likely homozygous for the trait. (FA2020 pg. 94) +6
jdc_md  you trick me nbme. veryy veryy tricky +1
... cassdawg made a comment on nbme17/block0/q#0 (An 80-year-old man with Type 2 Diabetes Mellitus is...)
 +9 
submitted by cassdawg(924)

Pelvic splanchnic nerves carry the parasympathetic fibers that are responsible for hindgut intestinal motility including voiding (image). [FA2020 p364].

Diabetes mellitus can cause nerve damage and gastroparesis, treated with metoclopromide (FA2020 p400).

... cassdawg made a comment on nbme17/block2/q#13 (28 yo woman, 18 weeks gestation and palpitations)
 +8 
submitted by cassdawg(924)

In agreement with the other post: (see FA2020 p331)

You would want to check FREE T4 because pregnancy increases Thyroid binding globulin. It is possible she might have increased overall T4, but NOT have hyperthyroidism because the free T4 is normal (i.e. her increases amount of thyroid binding globulin has bound more T4, and since our bodies respond to the concentration of free T4 only, the hypothalamus should ensure that the free T4 is kept constant; this would appear as increased overall T4)

Another way of thinking of this:

  • Overall T4 = bound T4 + free T4

If we increase bound T4 and keep free T4 the same, we would still increase overall T4. Thus to know if she truly has hyperthyroidism we must look at free T4 concentration.

lpp06  Does Overall T4 stay the same because TBG+T4 can last longer in circulation? Cause I always struggle thinking that free T4 is low because its being bound by the extra TBG +
covid_19  I'm not sure if I'm interpreting your question correctly, but I thought overall T4 increases in pregnancy? The way I think of it is that early in pregnancy, Ξ²-HCG (acting like TSH) β†’ ↑ free T4 β†’ ↓ TSH via (-) feedback β†’ TSH back to nml as ↓β-HCG during pregnancy (i.e. gestational thyrotoxicosis). If the mom really has hyperthyroidism, then free T4 remains high and TSH low even as Ξ²-HCG ↓ and ↑TBG. Later in the pregnancy, estrogen β†’ ↑TBG β†’ ↓ free T4 β†’ TSH release β†’ ↑ free T4 to regain equilibrium. (bound T4: free T4) 2:2 (nml) β†’ 3:1 β†’ 3:3 (new nml where there's a relative increase in free T4 AND overall T4). What are your thoughts on this? +
topgunber  Overall t4 increases, but when t4 is bound to thyroid binding globulin it is not active, therefore someone would not show characteristics of hyperthyroidism if they had high thyroid binding globulin and high total t4. Basically, free t4 is the actual amount of thyroid hormone that can cause a physiologic effect. As the first comment says, total thyroid hormone and thyroid binding globulin are increased in pregnancy. Thus to check for hyperthyroid we are concerned only with free t4 (if it is low then the patient would be hypothyroid) +
... cassdawg made a comment on nbme17/block3/q#24 (10 yo girl, well-child examination)
 +8 
submitted by cassdawg(924)

Here is a great image showing the timeline for the different pubertal changes in males and females. Tanner stages are found in FA2020 p673.

In females, the earliest detectable sign of pubertal change is breast bud development which only slightly precedes pubic hair development. In males, testicular enlargement is the first detectable sign.

flapjacks  You share excellent charts. Thank you! +1
... lfcdave182 made a comment on nbme17/block1/q#28 (12 yo boy, swimming in mountain stream; immersed in 60-degree water for 20 minutes)
 +7 
submitted by lfcdave182(30)

Cold temperature: Causes peripheral vasoconstriction and central vasodilation

  • Increased central blood volume --> Lower ADH due to increased blood volume through kidneys
  • Increased central blood volme --> leads to atrial stretching, increased preload --> Increased ANP release
passplease  what organs are considered "central"? I initially thought that the kidneys would not be getting more blood with most of the blood flow going to the lungs and heart +1
brise  Same :( +
drdoom  the kidneys are the lungs for waste products that can't be expelled via your breathe. (another way of saying this is: the lungs are like the kidneys of your mouth: instead of urinating out of your mouth, you "pee out" CO2 in the form of expired air.) tl;dr the kidneys are very vital organs!! +1
... waitingonprometric made a comment on nbme17/block2/q#22 (60 yo man, 1 month of progressive shortness of breath)
 +7 
submitted by waitingonprometric(137)

FA2019, pg. 666:

Based on the findings of decreased breath sounds, dull percussion, and decreased tactile fremitus, pleural effusion is your answer.

This was more of a rule-out question than a remember-the-arrows-on-a-page-in-FA question for me!

Breath sounds are decreased, so you can rule out asthmatic bronchitis (wheezing) and pulmonary embolism (normal breath sounds, but tachypneic). Bronchiectasis can have a number of findings--crackles, rhonchi, wheezing, mid-inspiratory squeaks, etc.

Emphysema (loss of alveolar septal tissue) and pneumothorax have increased air in the lungs, therefore, they will be hyperresonant on percussion, so rule those out too.

Tactile fremitus decreases with most everything, but consolidation--low frequency sounds travel well in dense material (lobar pneumonia), but travel poorly through liquid (pleural effusion). Therefore, based on decreased fremitus, rule out pneumonia.

So...you're left with pleural effusion as your answer!

mw126  Physical exam findings related to the FA table for pulmonary embolism are usually normal, may have a pleural friction rub over the area of infarct. +
... lfcdave182 made a comment on nbme17/block4/q#20 (45 yo man, 4 days of yellow skin)
 +7 
submitted by lfcdave182(30)

Pg 391, FA 2020

  • Alcoholic hepatitis: Swollen and necrotic hepatocytes with neutrophilic infiltration; Mallory Bodies (Intracytoplasmic eosinophilic inclusions of damaged keratin filaments)
cheesetouch  FA2018 P385 +1
... cassdawg made a comment on nbme17/block0/q#0 (A protein found in the brown adipose tissue of mice...)
 +7 
submitted by cassdawg(924)

This protein is an uncoupling agent (likely thermogenin which is found in brown adipose and serves to increase heat production. Uncoupling agents will cause increased permeability of the mitochondria membrane, necessitating more oxygen consumption in order to generate the same ion gradient. Since more oxygen is consumed to generate the same gradient, more oxygen would be consumed to generate the same amount of ATP, so the ratio of oxygen consumption to ATP generation increases. (FA2020 p78)

Another way of thinking about this is that oxygen will continued to be consumed to attempt to generate the gradient, but the leaky membrane will prevent the gradient from being formed properly and therefore prevent ATP from being formed. Thus there is the same amount of oxygen consumed for little to no ATP being made so again the ratio of oxygen consumption to ATP generation increases. This is closer to what actually happens in the body but I found it easier to think about it the first way.

feochromocytoma  Exactly, the electron transport in the mitochondria will keep going, but ATP synthesis would stop, which causes production of heat. +
thegout  if you're like me, you picked decreased ratio of oxygen to ATP in a brain fart without thinking about what a ratio is, gotta read the answers more carefully in long grueling exam. +2
... cassdawg made a comment on nbme17/block0/q#0 (A 19-year-old man is admitted to the hospital...)
 +7 
submitted by cassdawg(924)

He has an upper motor neuron lesion which is causing paralysis on his left lower side, so he will have hyperreflexia on this side. Thus the deep tendon reflex will actually be increased/strongest in his left achilles tendon initially after the accident. [FA2020 p529]

kbizzitt  A radial nerve lesion is a LMN lesion (hyporeflexia). You can basically divide it by pre-anterior horn, and post-anterior horn of the spinal cord. After the synapse at the anterior horn it becomes a lower motor neuron. Before that (along the spinal cord and up back up to the motor cortex) is considered upper motor neuron. +1
... bingcentipede made a comment on nbme17/block0/q#0 (A 55-year-old woman has left flank pain and gross...)
 +7 
submitted by bingcentipede(209)

The classic triad of a renal cell carcinoma is: 1) hematuria; 2) flank pain; and 3) a palpable flank mass. The classic RCC comes from a VHL mutation. No VHL means you can't inhibit HIF (hypoxia inducible factor). This leads to uncontrolled activation of VEGF, leading to the hypervascular mass.

cheesetouch  FA2018 P583 +1
... compasses made a comment on nbme17/block1/q#20 (24 yo man, history of intravenous drug use, brought to ER 30 minutes after he could not be aroused)
 +6 
submitted by compasses(7)
unscramble the site ⋅ remove ads ⋅ become a member ($39/month)

ttalo ccnttnoinroea = 0lg0/.3m x L002 = 6m e0gh okto hte urdg 6 rsohu ago @ hltaf- fo 2 28=0=mshhru=1=rousgshg6or u00gsh=m=g ho2 r=o= s400rm464um2

... waitingonprometric made a comment on nbme17/block2/q#46 (38 yo man, brought to ER 30 minutes after being found near his home, unsbale to stand upright)
 +6 
submitted by waitingonprometric(137)

Metabolic acidosis because the arterial pH goes in the same direction as the bicarb and pCO2 (i.e. both pH and bicarb/pCO2 are decreased from normal); in primary respiratory acidosis/alkalosis the arterial pH goes in the opposite direction as the bicarb and pCO2.

Once you know that it is a primary metabolic acidosis, you have to check for concomitant respiratory disorders. Do this with Winter's formula:

expected pCO2 = 1.5(HCO3) + 8 +/- 2

so... expected pCO2 = 1.5(11) + 8 +/- 2 --> pCO2 = 24.5 +/- 2 = expected pCO2 is between 22.5-26.5, therefore, 23 is in the expected range, no concomitant respiratory process

baja_blast  Was looking for "Metabolic acidosis and respiratory acidosis" and was wondering why it wasn't a choice. Totally forgot about Winter's formula. Thanks!! +3
... cassdawg made a comment on nbme17/block3/q#33 (Female newborn delivered at 36 weeks, respiratory distress)
 +6 
submitted by cassdawg(924)

This is a Congenital Diaphragmatic Hernia (FA2020p370).

Conginital diaphragmatic hernias are caused by a congenital defect of the pleuroperitoneal membrane which allows contents of the abdominal cavity to herniate upward, and displace the contents of the thorax (hence why our baby has displacement of the mediastinal contents to the right). This also leads to lung malformation and respiratory distress (hence the low apgar scores). Because the stomach is likely herniates upward, a nasogastric tube placed would appear in the left mediastinum (because that is where the stomach is). Further, there is an absence of bowel gas in the abdomen likely because the bowels are herniated into the thorax.

cheesetouch  FA2018 P364 CDH +1
... cassdawg made a comment on nbme17/block0/q#0 (22-year-old woman, gravida 1, para 1... vaginal bleeding)
 +6 
submitted by cassdawg(924)

Ligation of the internal iliac artery is used to stop postpartum uterine bleeding while preserving fertility as the ovarian arteries provide collateral circulation (FA2020 p640).

Here is an image showing the uterine artery coming off the internal iliac with the ovarian artery collateral.

Other answers:

  • The external iliac gives rise to the femoral artery, inferior epigastric artery, and the deep circumflex iliac artery
  • The internal pudendal artery supplies the external genetalia and perineum via arteries such as the inferior rectal artery (anal canal BELOW the pectinate line), perineal artery, and ldorsal/deep arteries of the clitoris or dorsal/deep arteries of the penis
  • The median sacral artery is small and supplies the coccyx/sacrum/lumbar vertebrae
  • The obturator artery is a branch of the internal iliac which gives off the pubic branch (supplies pelvic muscles) and acetabular branch (supplies head of the femur)
cheesetouch  fa2018 p624 +1
... tinyhorse made a comment on nbme17/block0/q#0 (A 45-year-old woman comes to the physician for a...)
 +6 
submitted by tinyhorse(6)

Frankly pretty floored that anybody thought that this question contained enough information for someone to confidently answer it.

The question has you assume that both parents are heterozygotes at the locus. Why? I assume I'm missing some esoteric fact about P450 allele frequencies.

flapjacks  I got lucky guessing the same % chance that siblings share HLA markers +2
baja_blast  I agree with OP seriously no idea how anyone could have gotten this right without totally guessing it. Am I missing something here?? +1
sschulz2013  However, if one parent is homozygous and the other is heterozygous, then it works out that the sister will have the same allele 50% of the time, not 25%. So still not sure about the above answer. Don't think assuming the parents are both heterozygotes is something we should have to do. There is probably more to it than just that. +1
j44n  the probability for being the same gene as a sibling thats homozygous is always 25% this has been on just about every practice NBME +
... cassdawg made a comment on nbme17/block0/q#0 (A 50-year-old man comes to the physician 3 days after)
 +6 
submitted by cassdawg(924)

This individual is suffering from hypocalcemia, which explains the seizures, twitching (reason for Chvostek sign - tapping of the facial nerve causing contraction of the muscles), and spasms (similar to Trousseau sign - inflation of the blood pressure cuff causing carpal spasm). It also may present with QT prolongation and numbness and tingling (as described). It is also important to note that though mild hypocalcemia causes hyporeflexia, extreme hypocalcemia can lead to hyperreflexia, tetany, parasthesias, and seizures (see here). Basically you cannot bank on the reflexes.

Hypercalcemia would present with stones (renal), bones(pain), groans(abdominal pain), thrones( urinary frequency), psychiatric overtones(anxiety, altered mental status).

The others answers are incorrect because:

  • Bicarbonate disturbances are related to acid/base imbalance and would not present with the symptoms described.
  • Chloride:
  • Hypochloremia (associated with excessive vomiting) is typically accompanied by hyponatremia and typically presents with weakness/fatigue and dehydration.
  • Hyperchloremia disturbances are generally related to kidney issues and when signs present they are dehydration, excessive thirst, fatigue, and dry mucus membranes
  • Potassium:
  • Hypokalemia presents with muscle cramps, spasm, and weakness but also with cardiac anomalies (arrhythmias) and flattened T-waves on ECG.
  • Hyperkalemia presents with wide QRS and peaked T waves on ECG, weakness, and arrhythmias.
  • Sodium:
  • Hyponatremia can cause seizures and stupor, but it also typically presents with nausea and vomiting, weakness/fatigue, and confusion. Here is a good hyponatremia pneumonic (SALTLOSS - Stupor, Anorexia[nausea, vomiting], Lethargy, Tendon reflexes decreased, Limp muscles/weakness, Orthostatic hypotension, Seizures, Headache)
  • Hypernatremia presents with irritability and stupor

Electrolyte Disturbances: FA2020 p591

... cassdawg made a comment on nbme17/block2/q#1 (A 38-year-old man comes to the physician because of)
 +6 
submitted by cassdawg(924)

Loratadine is a second generation antihistamine and thus would be preferred in this patient as it does not cause sedation. [FA2020 p686]

Since he works operating heavy machinery, it would be preferred to put him on a second generation antihistamine. Bropheniramine, hydroxyzine, and diphenhydramine are first generation antihistamines which cause sedation.

Ranitidine is a histamine H2 blocker used to decrease secretion by parietal cells in peptic ulcer disease, gastritis, and gastric reflux [FA2020 p399]

cheesetouch  FA2018 P667 +
... lfcdave182 made a comment on nbme17/block1/q#14 (21 yo man, excruciating anal pain for 4 hours)
 +5 
submitted by lfcdave182(30)

Pg 366 FA 2020.

  • Below pectinate line: External hemorrhoids: Painful if thrombosed: Inferior Rectal Vein.
neovanilla  Note: pg 365 FA 2020 states: anorectal varices: portal <--> systemic: superior rectal <--> middle and inferior rectal. Not sure if that's correct, but definitely the info cited in pg 366 is correct +
cheesetouch  FA 2018 p360 +
... lpp06 made a comment on nbme17/block1/q#14 (21 yo man, excruciating anal pain for 4 hours)
 +5 
submitted by lpp06(26)

Hemorrhoids are dilatations of arteriorvenous plexuses in the rectum. Blockages on the arterial side will not cause the plexus to fill while venous thromboses will cause a back up of fluid.

Clues for hinting which vein are the location at the anal margin and that he was in extreme pain. External hem's will be painful, pointing towards inferior rectal as the answer since it drains below the pectinate line where external hem's are found.

skilledboyb  anyone know how to rule out middle rectal vein thromboses? +
prostar  it is just that when both are in option go for inferior rectal vein. this is more apt. or else both are correct. +
... osler_weber_rendu made a comment on nbme17/block1/q#21 (42 yo farmer, 7 mm red scaly plaque on ear)
 +5 
submitted by osler_weber_rendu(86)

What you can see is

1.Hyperkeratosis (thickened stratum corneum) 2.Parakeratosis (you can see the nuclei very clearly in the stratum corneum) 3.Dysplasia (notice keratinocytes hyperchromatic and large nuclei go up almost all the way to the top. This isnt so in normal skin)

all this fits actinic keratosis

cassdawg  Actinic keratosis is FA2020 p482 if anyone needs it! +4
baja_blast  FA2019 p. 472 +1
cheesetouch  Sweet name @osler_weber_rendu #represent #cureHHT +
... abkapoor made a comment on nbme17/block2/q#27 (Polymorphic marker with three alleles, 1, 2 and 3, tightly linked to gene for polycystic kidney disease)
 +5 
submitted by abkapoor(11)

The best way to explain this:

Firstly, the only possible combinations for the child are 1,2 or 2,3, one from each parent (that eliminates A, C & D)

They are looking for the genotype for III if he is unaffected by the disease. In I, we see that the male is affected, and the female is not. In II, both the female and male are affected.

If II female is 1,1 one of each 1 alleles comes from each parent, II male, we recognize that the 3 allele has to come from I female, and 1 allele HAS to come from I male. Therefore, one can infer that it is the one of the 1 genes from the I male causing the disease. If III is unaffected, the only option would be 3,2.

... icedcoffeeislyfe made a comment on nbme17/block2/q#34 (40 yo man, skin extremely sensitive to sunlight)
 +5 
submitted by icedcoffeeislyfe(35)

FA 2020 pg 425

Porphyria cutanea tarda-- defect in UROD in the heme synthesis pathway that causes photosensitivity and blistering

bingcentipede  Most common porphyria, too +2
brise  The thing that got me screwed was the "increases synthesis of compounds"; like what compounds? +
i_hate_it_here  I swear they just love to say shit to throw us off smh +
... baja_blast made a comment on nbme17/block2/q#39 (40 yo man, interstitial pulmonary fibrosis)
 +5 
submitted by baja_blast(91)

Fibrosis pulls the airway open, increasing radial traction and decreasing resistance to airflow.

Here is a picture comparing fibrosis (increased traction) to emphysema (decreased traction) to a healthy lung.

... icedcoffeeislyfe made a comment on nbme17/block3/q#9 (40 yo African American woman, 2 weeks of fever, malaise, dyspnea)
 +5 
submitted by icedcoffeeislyfe(35)

The pt has sarcoidosis via the classic demographic association and the b/l hilar adenopathy

in sarcoid you get increased ACE and you also get hypercalcemia due to increased 1-alpha-hydroxylase (via acitvated macrophages) which leads to increased vitamin D

FA2020 pg 676

jdc_md  black females lungs= sarcoidosis +
... lpp06 made a comment on nbme17/block3/q#16 (14 yo boy, daily headaches for 2 months)
 +5 
submitted by lpp06(26)

I think inhalants are a new add to FA2020 (at least they weren't in Zanki), so I go to this one by elimination:

eliminated Meth + PCP + Cocaine because they're Stimulants.

eliminated EtOH b/c it would take a long time for cerebellar atrophy to manifest and I doubt a 14yo has been drinking since birth.

... cassdawg made a comment on nbme17/block3/q#49 (48 yo nulligravid woman, 3 months excessive uterine bleeding)
 +5 
submitted by cassdawg(924)

Uterine conditions FA2020 p648

  • Adenomyosis - extension of uterine endometrial glandular tissue into the uterine myometrium; would present with dysmenorrhea or abnormal uterine bleeding with a uniformly enlarged soft and globular uterus
  • Endometrial hyperplasia - abnormal endometrial gland proliferation, abundant tissue but no dysplasia; presents with heavy bleeding during menses, more common in nulligravid due to excess estrogen
  • Endometrial metaplasia - metaplasia is transformation of one cell type to another; this can be a benign process or associated with malignancy but would not likely present with abundant tissue on curretage
  • Endometriosis - endometrium-like glands/stroma outside of the uterine cavity (in ovary, pelvis, or peritoneum); presents with PAIN and heavy bleeding or dysmenohorrea
  • Endometritis - inflammation of the endometrium, associated with retained products of conception or foreign body
... cassdawg made a comment on nbme17/block0/q#0 (15-year-old, lesions on neck, acid-fast bacilli,...)
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Mycobacterium leprae likes cool temperatures (FA2020 p141)

Mycobacterium leprae is an acid-fast bacteria which can cause two skin manifestations:

  • Lepromatous presents diffusely over the skin and with leonine facies and is more serious with a largely Th2 response and high bacteria load
  • Tuberculoid (what our patient has) presents with a few hypoesthetic hairless skin plaques with a largely Th1 response and low bacteria load

Leprosy likes cool temperatures so it infects skin and superficial nerves. Even without knowing the organism, the link could also be potentially inferred!

bingcentipede  In addition, the only other acid-fast bacterium is Nocardia; they would have to describe it as branching/filamentous (NOT a bacillus!). +2
... cassdawg made a comment on nbme17/block0/q#0 (59-year-old comes to the physician... lack of muscle...)
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Looking at the symptoms, they fit with cerebellar issue, as the cerebellum is responsible for modulating movement and aiding in coordination and balance. [FA2020 p499]

She does not have paralysis or parasthesia but rather lack of control of movement, making injury to the cerebrum less likely. Further, her issues are not localized to the upper or lower extremity and do not fit with any syndrome of spinal cord. Ataxia is also typically a buzzword for associations with the cerebellum. In this case, her limb ataxia is likely from a metastasis to the left cerebellar hemisphere.

If you want to review:

Common brain lesions can be found FA2020 p511.

Spinal lesions can be found FA2020 p530.

waitingonprometric  Also for completeness--this lesion is probably in a lateral hemisphere of the cerebellum. From FA "Cerebellar hemispheres are laterally located--affect lateral limbs." Lesions to the central portion of the cerebellum (vermis) usually cause "truncal" ataxia. +2
... cassdawg made a comment on nbme17/block0/q#0 (A female newborn is delivered at 38 weeks'...)
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This child likely has a meningomyelocele (neural tube defect caused by failure of the neuropores to fuse in week 4, FA2020 p491). Neural tube development in general occurs weeks 3-8 (FA2020 p612) which corresponds most closely to days 15-40. Organogenesis and most vital development also occurs during this period.

Days 1-10 are typically "all or nothing" in that a defect would cause fetal demise.

Days 60-75 (~weeks 8-10) are associated with external genital development, palate and teeth.

The most critical periods are typically over by week 10 (see this chart)

... andro made a comment on nbme17/block0/q#0 (A 29-year-old woman comes to the physician because...)
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Patient with Primary Hypothyroidism (problem with the gland itself ) treated with T3

  • In normal physiology T4 is converted to T3 and less commonly ( rT3) . As such most of the T3 in the body is derived from the peripheral deiodination of T4 to T3
  • Also note that TSH secretion by anterior pituitary is under negative feedback control by both Free T3 and T4

So what happens when we give our Patient T3.
- firstly , we inhibit secretion of TSH from the pituitary gland . ( TSH decreases ).

This means less stimulation of the Thyroid and less hormone production . The Throid hormone it primarily makes and releases is T4 , ( and so T4 decreases ) . Naturally you would also expect a decrease in T3 but patient is taking exogenous T3( and so T3 increases )

schep  I messed this up because I know treatment of primary hypothyroidism is usually with levothyroxine (T4). I totally skimmed the part where we are told she is being treated with T3 +1
jdc_md  ^nbme is asshoe! +1
topgunber  side note thyroglobulin would also be low and is asked on uworld +
cheesetouch  Thyroxine = T4 +
... abkapoor made a comment on nbme17/block0/q#0 (A 56-year-old woman comes to the physician for a...)
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Just to clarify, complete resolution after injury can only occur if the basement membrane remains intact as this below this is where the stem cells are located. If there is damage to the basement membrane, you will have incomplete resolution and scar formation. The best example of this is skin injury.

... kstebbins made a comment on nbme17/block1/q#1 (80 yo woman evaluated for suspected temporal arteritis)
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submitted by kstebbins(9)

I was thrown off because Pathoma/Dr. Sattar and pixorize say it is critical to start steroids ASAP to avoid permanent damage to the ophthalmic artery and blindness in patients suspected of having Giant Cell (Temporal) Arteritis.

This means not waiting for diagnostic confirmation.

However a 99% sensitivity does not equate to a 99% certainty of GCA/TA. So additional testing is the best answer choice even though her elevated ESR gives us strong suspicion of GCA/TA.

nsinghey  exactly, the reason why its not steroids is because that answer choice says the diagnosis of TA has been established with 99% certainty which is NOT true +1
j44n  this question threw me because you tx this on clinical suspicion alone. So i was torn between the right answer and the fact that if you repeated ESR again and its positive you youd the give steroids +1
... andro made a comment on nbme17/block1/q#8 (6 week old girl, 6 days of vomiting a small amount of milk)
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Differential Diagnosis of Newborn/Neonatal Vomiting

-Benign gastroesophageal reflux ( i.e immature lower esophageal sphincter ) regurgitation of food shortly after feeding .
No further symptoms , healthy children with normal development

-Hypertrophic pyloric stenosis
Regurgitation - projectile nonbilious vomiting electrolyte imbalances ( alkalosis and hypokalemia ) * physical examination may reveal an olive mass on palpation of epigastrium
*typically starts from between 2nd and 7th week of age

-Midgut volvulus /Malrotation /Duodenal atresia * bilious vomiting * abdominal distention * Imaging may reveal signs like the double bubble sign ( duodenal atresia ) etc

Note: The list is not exhaustive as there are many more causes associated with newborn vomiiting

covid_19  To add on to Benign GER, I couldn't find anything in a cursory look through FA and also didn't know that GER was a thing in neonates, so I found this nice and concise article in UpToDate: https://www.uptodate.com/contents/gastroesophageal-reflux-in-premature-infants +
i_hate_it_here  I don't understand why Esophageal spasm isn't right +
topgunber  I would say esophageal spasm would cause immediate regurgitation or inability to swallow properly. so we would be looking for dysphagia. +1
... waitingonprometric made a comment on nbme17/block1/q#35 (42 yo woman, 3 years of intermittent facial rash)
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submitted by waitingonprometric(137)

According to FA2019, pg. 468:

Rosacea is a facial disorder characterized by erythematous papules and pustules, but no comedones (hence this patients erythema over the nose and cheeks, with scattered telangiectasias and a few papules); may be associated with facial flushing in response to external stimuli (hence, blushing easily, spicy foods precipitating a flushing reaction).

Wrong answers:

Acne vulgaris would present with comedones.

Carcinoid syndrome can also present with episodic flushing triggered by foods, alcohol, or stress. But, this would also present with systemic symptoms--diarrhea, weakness, SOB, sweating, etc.

Pityriasis rosea is a viral rash that lasts between 6-12 weeks and would not be expected as the cause based on this patient's 3-yr history.

Seborrheic dermatitis causes an itchy rash with flaky scales (no flaking present in our patient here),

... cassdawg made a comment on nbme17/block1/q#48 (9 yo girl, poor growth over 1 year; below 3rd percentile for height; 10th percentile for weight)
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submitted by cassdawg(924)

She has a craniopharyngioma, the most common childhood supratentorial tumor which is derived from remnants of Rathke's pouch (FA2020 p528). Craniopharyngiomas commonly have calcification and can cause hypopituitary issues (like low HGH). Suprasellar is also the location of the pituitary, and pituitary tumors in general cause bitemporal hemianopsia due to compression of the optic chiasm.

Rathke's pouch (where craniopharyngiomas and anterior pituitary are derived from) is derived from the surface ectoderm of the oral cavity.

Note that the neurohypophysis (posterior pituitary) is derived from neural ectoderm while the adenohypophysis (anterior pituitary) is derived from surface ectoderm of the oral cavity.

waitingonprometric  If you can recognize that this is a craniopharyngioma based on "calcified cystic mass in the suprasellar region," then you can think "cranio-" mass in the brain, "-pharyngioma" from structures connected to the mouth. Always works for me! +6
cheesetouch  FA 2018 P512 +1
... cassdawg made a comment on nbme17/block2/q#20 (38 yo woman, 2 years of pain and heavy flow with menses)
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submitted by cassdawg(924)

This woman likely has endometriosis, characterized by cyclic pelvic pain, bleeding, and associated with infertility (FA2020 p648). It is associated with "chocolate cysts" on the ovaries. Proliferative endometrial tissue would be found on biopsy

Endometriosis scar tissue/adhesions can cause the uterus to stick in a backwards position (retroverted) according to https://www.healthline.com/health/womens-health/tilted-uterus

Polycystic ovarian syndrome is associated with obesity would also likely have symptoms of hisutism and acne as well as infertility. It also presents with amenorrhea or oligomenorrhea. [FA2020 p645]

waitingonprometric  Also, rule out cancers because no weight loss, symptoms are not constant throughout month, and symptoms are not getting progressively worse over the 2-yr history of pain +4
cheesetouch  FA2018 P630 +2
... cassdawg made a comment on nbme17/block3/q#26 (34 yo man, lightheaded after 12 miles of marathon)
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submitted by cassdawg(924)

This question is essentially asking what happens to sympathetic and parasympathetic efferents in the setting of hypovolemia/dehydration. In this setting, there would be lower blood pressure and thus this would cause reduced firing of the carotid baroreceptors, ultimately leading to feedback which stimulates the sympathetic nervous system (to increase heart rate and cause peripheral vasoconstriction in order to compensate for hypovolemia) while also inhibiting the parasympathetics.

saqeer  silly me thought they were asking about heat stroke. +
... breis made a comment on nbme17/block4/q#16 (32 yo man, 3 months of swelling, ternderness of breasts)
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submitted by breis(44)
unscramble the site ⋅ remove ads ⋅ become a member ($39/month)

HCG enntosiicj dwon augelert hte utpaiiyrt raeesel fo GRnH.

vehwero CGH alaph uutnsib nca smuaieltt lscel ieefunlcdn yb L,H HSF, HT.S

cassdawg  (FA2020 p633) - Basically HCG acts like FSH which stimulates estradiol production by the sertoli cells (see http://www.ansci.wisc.edu/jjp1/equine/male_endo/estrpath.html). There is no feedback inhibition since it is injected so there are elevated levels of estradiol causing gynecomastia. +10
j44n  also FSH upregs aromatase so you increase test (LH) and increase aromatase (FSH) that then converts that test to estradiol +
... covid_19 made a comment on nbme17/block4/q#23 (72 yo man, weakness and fatigue)
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submitted by covid_19(4)

Aplastic anemia: anemia, leukopenia, thrombocytopenia

CML, i.e. leukemias: anemia, ↓ mature WBC, ↓ plt, peripheral blood smear shows mature & maturing granulocytes (FA 2020, p. 432)

Ξ²-thalassemia major: microcytic, hypochromic anemia with target cells and anisopoikilocytosis, skeletal deformities, etc. (FA 2020, p. 418)

Cobalamin deficiency: d/t malabsorption, pancreatic insufficiency, gastrectomy, or insufficient intake, neurological Sx

Personally, I got this wrong, because to me, the RBCs in that smear looked both larger and more irregularly shaped, so in hindsight, I really should've honed in more on the HPI, i.e. the patient really has anemia and no other relevant PMx.

flapjacks  I believe Goljan mentions that the #1 cause of anemia in older adults is GI bleeds +3
flapjacks  (colon cancer) +1
mark0polo  Also, B-thalassemia major would present in childhood, not in a 75 year old man +2
... cassdawg made a comment on nbme17/block4/q#34 (16 yo girl, 2 years of intermittent fainting while standing)
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submitted by cassdawg(924)

Answering this question requires general knowledge of the catecholamine synthesis pathway (FA2020 p83).

The approach I took to this question was mainly elimination of wrong answers:

  • MAO (monoamine oxidase) could be eliminated because she is lacking epinephrine and since MAO is involved in the breakdown of catecholamines, a deficiency in MAO would increase concentrations of norepinephrine and other catecholamines.
  • Norepinephrine transporter could be eliminated because inhibition of reuptake of norepinephrine would, again, increase norepinephrine concentrations and she has decreased concentration.
  • Tyrosine hydroxylase can be eliminated because it is the first step in catecholamine synthesis and required for dopamine synthesis, and as she has increased dopamine this step is not deficient.
  • Amino acid decarboxylase, or L-amino acid decarboxylase also called DOPA decarboxylase, is also required in dopamine synthesis and can be eliminated because of her increased dopamine concentration.

This leaves the answer, dopamine beta-hydroxylase.

waitingonprometric  Awesome answer, but just to add a bit more about why the correct answer makes sense. Dopamine beta-hydroxylase is the enzyme that converts dopamine to norepinephrine. Therefore, the increase in dopamine conc. when rising from supine to standing, is trying to tell us that her body is ramping up the SNS to compensate for all of the blood rushing to her feet when she stands up. Ramping up the SNS requires production of catecholamines, but without this enzyme, synthesis of NE only gets to the dopamine stage and lots of dopamine backs up behind this enzyme. +10
... cassdawg made a comment on nbme17/block0/q#0 (14-year-old boy is brought to the emergency...)
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Maxillary nerve injury (specifically the infraorbital nerve) is an important potential complication of orbital rim fractures (e.g. blow out fractures) [See here]

Here is a picture of the territories of the different branches of the trigeminal nerve for sensation which could help you answer this question as he has numbness under the eye to the upper lip.

Orbital floor fractures can lead to entrapment of the inferior rectus, which can be a cause of pain on upward gaze and diplopia when asked to look upward. This is an ophthalmologic emergency (https://emedicine.medscape.com/article/825772-overview).

... cassdawg made a comment on nbme17/block0/q#0 (58-year-old man with supraventricular...)
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submitted by cassdawg(924)

This mainly has to do with the location of the SA node (see here). The SA node is located in the atrial wall at the junction of the superior vena cava and right atrium.

The AV node lies near the back of the intraventricular septum near the opening of the coronary sinus (the triangle of Koch defines the AV node location)

Other fun facts from UWorld about ablation and different sites of origin, etc:

  • Between the tricuspid and inferior vena cava (cavotricuspid isthmus) is the most likely location of a reentrant circuit causing atrial flutter
  • The pulmonary vein ostia is the most likely site of origin for AFib and therefore most likely targeted for catheter ablation to correct Afib
  • The right ventricular outflow tract and papillary muscles are the most likely site of origin for Idiopathic VTach (though it is more commonly from ischemic tissue)
  • An accessory pathway bypassing the AV node is the cause of Wolff-Parkinson-White syndrome (characteristic delta wave upstroke) and AV reentrant tachycardia
  • A slow pathway that reenters the AV node is the cause of AV nodal reentrant tachycardia and the slow pathway would be targeted for ablation
... cassdawg made a comment on nbme17/block0/q#0 (45-year-old man with poorly controlled type 2...)
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submitted by cassdawg(924)

First step to approach this problem is to eliminate Listeria monocytogenes (it is a gram positive ROD) and both staphylococcal species (Staph is always catalase positive), which leaves us with Streptococcus pneumoniae and Enterococcus faecalis.

Strep pneumoniae is an alpha hemolytic strep while enterococcus is typically gamma hemolytic, so seeing as there is no hemolysis on blood agar (meaning gamma hemolytic), Enterococcus is the correct answer. VRE (vancomycin resistant enterococcus) are also an important cause of nosocomial infections such as from his venous catheter.

Here is a good algorithm/flow chart for gram positive identification!