NBME 28 Flashcards
(75 cards)
1
Q
which organ in CNS mediates conscious v/s unconscious proprioception?
A
Conscious - CB ant lobe
Unconscious - DCML (along with 2-pt discrimination, vibration)
2
Q
Supination v/s pronation muscles?
A
Pronation - pronator teres
Supination - biceps brachii and supinator muscle in forearm
3
Q
New onset rash that is photosensitive + serum tryptophan is dec + Urine has inc alanine, valine, isoleucine, leucine, phenylalanine and tryptophan. Which other substance is dec?
Vit B1
Niacin
A
Ans: Niacin
Yes DDx is MSUD (Branched Alpha-ketoglutarate DH - uses B1) but urine shows more AAs inc - like tryptophan, phenylalanine etc so think of Hartnups (Also rash)
Since tryptophan is less - its mainly dec Niacin and SRT rmmbr pathway!
4
Q
Additive effect drugs?
A
ASA + Acetaminophen
5
Q
Permissive effect drugs?
A
NE + cortisol
6
Q
Synergistic effect drugs?
A
Ampicillin + gentamicin
7
Q
Tachyphylaxis development in?
A
Leuprolide
A1 agonist
Nitrates
8
Q
Fragile X synd?
A
Methylation issue - Trinucleotide repeat on X - chr (CGG on FMR1 gene)
Intellectual disability, elongated face, large ears, macro-orchidism + high arched palate.
Inc risk of MVP
9
Q
Apparently lentogo maligna = malignant melanoma
v/s compound nevus?
A
Lentigo maligna:
ABCDE hota h
Compound nevus:
No ABCDE
10
Q
Proportion of newborns with CHD last yr is?
Prevalence
Incidence
A
B!!
Prevalence is calculated as the ratio of the number of people with a disease divided by the total number of at-risk persons in a population at a particular point in time but incidence is over a yr and new cases so yesss
11
Q
Protein C inhibits?
A
F-5 and 8
12
Q
hypoTN in case of septic shock?
NO excess
H2O2 pdtn
Induction of endothelin adhesion molec
A
A!!
H202 - helps kill bact and cause tissue injury
Induction of endothelin adhesion molec - in the recruitment and migration of leukocytes to sites of infection and injury. Local role
13
Q
If normal diff of endoderm in lung bud is an issue, what is affected?
A) Capillary patterns
B) Cartilage in bronchi
C) Smooth muscle onthe bronchi
D) Surfactant secretion
E) Tracheal rings
A
B,C,A,E - Mesoderm
D - is only endoderm
14
Q
Pt is a suspected case of colon Ca. Physician suggests Colonoscopy but he wants FOBT. Issue is with?
Low sensitivity
+ve predictive value uncertain
A
A!!!
B is true but not immediate concern - Positive predictive value is based on both test specificity and the pretest probability of disease.
15
Q
How infliximumab inc risk of Tb?
A
Infliximumab is TNF-alpha inhibitor - this is secretd by Ms to maintain granuloma + walling off the bact
16
Q
Only PTT raised and is corrected when u add plasma a from Hemophilia A pt. Dx?
A
Pt has hemophilia B - cuz plasma from hemophilia A that has F-9 helped correct it
17
Q
Metaplasia description?
a) Intestinal metaplasia of squamous epithelium
b) Squamous metaplasia of submucosal gland
A
A!! obv the sq epi –> intestinal type
18
Q
Normal Art PO2 but dec arterial O2 content and dec mixed venous O2 content. Cause?
A
Anemia
19
Q
True abt T3 n T4?
a) Both T5and T4 enter the nucleus
b) T3 is converted to T4in the cytosol
c) Thyroid hormone receptors preferentially bind T4 over T3
A
Answer is A
T4 —> T3 peripherally via 5’-iodinase and R binds to both in nucleus.
20
Q
What is the significance of:
G1
S
G2
M phases
A
G1 - cellular contents (- chromosomes) duplicate
S - DNA synthesis
G2 - cell growth and mitotic cyclin synthesis
M - Nuclear envelope is +P and cytokinesis
21
Q
HypoNa acute + wt gain. Pt in ED is semicomatose now post running. High pulse + low BP. Cause?
A
Fluid overload h (wt gain) + low Na + acute - has to be dilutional - Excess fluid intake
agar chronic hota toh - CHF + Liver cirrhosis
U can have cerebral edema.
22
Q
Metformin effects?
A) Decrease intestinal carbohydrate digestion
B) Increase beta-cell insulin secretion
C) Increase deposition of adipocyte fat
D) increase hepatic triglyceride synthesis
E) Inhibit hepatic gluconeogenesis
A
Inc insulin sensitivity matlab more Insulin effects
- Inc AA uptake - protein synthesis
- Inc FFA synthesis not TGs (TGs are produced by FFA breakdown)
- Inc glycogenesis
23
Q
Types of opioid R?
A
Mu - is all effects on sketchy
Kappa - reward signalling + mu
Delta - analgesia
sigma - memory and drug dependence
24
Q
Pt: HLADR3/6
Donor: HLA DR3/4
donor’s T-Ls will react with what?
A
DR6 obvvv
25
Pt has Vertigo, lightheadedness, Left UL weakness that is only present when he exercises otherwise gone. P.Ex shows?
a) Right carotid bruit
b) Supraclavicular bruit
Answer is B!
Its subclavian steal synd - atherosclerosis in subclavian proxinal to VA is the pathophysio
UL + vertebrobasilar issues
26
Zenker's diverticula - contrictor muscles are innervated by?
CN 9
CN 10
The vagus nerve innervates most of the pharynx except the stylopharyngeus muscle (CN 9) and possesses fibers that join with nerve fibers from the external laryngeal nerve, glossopharyngeal nerve, and sympathetic chains to form the pharyngeal plexus.
27
Sequencing of the B-globin gene shows a point mutation in a sequence 3' to the coding region in which AATAAA is converted to AACAAA. Consequently the amount of mRNA for (3-globin is decreased to 10% of normal. Which of the following functions in mRNA synthesis and processing is most likely encoded by the sequence AATAAA?
a) ) Cleavage and polyadenylation
b) Splicing of the initial mRNA transcript in the nucleus
A
Splicing of the initial mRNA transcript in the nucleus (Choice D) is the process by which introns are removed and exons are connected. Splice sites exist at the end of an intron and the beginning of an exon. Splice sites are recognized by snRPs, which are RNA-protein complexes that combine with the pre-mRNA to form a spliceosome. Mutations in splice sites can result in the aberrant inclusion of introns or exclusion of exons.
The AATAAA sequence encodes the polyadenylation signal. Mutations here would result in failure to polyadenylate the 3' end of the mRNA transcript and lead to early degradation within the nucleus prior to translation
28
Pt has high uric acid and gouty tophi. Cause:
A) Cigarette smoking
B) Drinking home-distilled liquor
B not A!!
Cigarette smoking has been linked to numerous pathologies including lung cancer osteoporosis, bladder cancer and chronic obstructive pulmonary disease. It has not been directly associated with gout flares and alteration of uric acid metabolism or excretion
29
Qn 48 block 1 look at it once plss
PAH clearance
30
RR?
This is often calculated as relative risk. The definition of relative risk is the incidence rate in the exposed group divided by the incidence rate of the unexposed
group. In this question, the incidence of infection in the turtle exposure group would be calculated as 60 infections divided by 30 total persons in the turtle exposure group (60/80 = 0.75). The incidence of infection in the non-turtle exposure group would be 40
infections divided by 120 total persons without turtle exposure (40/120 = 0.33). Relative risk would be calculated as the incidence of infection in the turtle exposed group divided by the incidence of infection in the non-turtle exposed group ((6G/3G)/(4Q/12G) = 2.25).
This signifies that the risk of infection in the group exposed to turtles is 2.25 times the risk of infection in the group not exposed to turtles
31
B2 effects on which organ?
Not heart thats B1
- Uterus
- Bronchial sm muscle
- Arteriolar dilation
32
Wallerian degeneration regeneration has?
Slow axonal anterograde transport
Protein synthesis in the dorsal root ganglia ceil bodies and axons and subsequent anterograde axonal protein transport to the axon terminal mediate peripheral
nerve regeneration. Slow anterograde axonal transport occurs when microtubule motor proteins transport cytoskeletai proteins such as neutofilaments and cytoplasmic proteins such as actin and glycolytic enzymes to the axon terminal. Slow anterograde axonal
transport occurs at approximately 1 mm per day and is slower than fast anterograde axonal transport or retrograde axonal transport. Therefore,
slow anterograde axonal transport is the rate-limiting step in peripheral nerve regeneration
33
pKa of substance closer to pH of surroundings. Ionized or non-ionized?
Ionized!!
At pH lower - nonionized
34
A pedigree is shown Most affected members also have a rare allele at a locus thought to
be closely linked to the disease locus. A father (individual lra-3) and his daughter (individual IV-3) have the disorder, but they have the wild-type allele at the finked focus. Which of the following is the most likely cause of these findings?
A) Random segregation
b) Recombination
b
Random segregation (Choice B) is a principle applying to meiosis, the separation of DNA into haploid gametes, which states that parental genes separate randomly and equally into gametes. Each gamete has an equal chance of getting each parental allele. It
does not impact the linkage of alleles at two closely located gene loci.
35
Systemic sclerosis?
Inc SVR + Mean coronary art pr + pulmonary vascular pr + dec LV compliance
36
A25-year-old woman comes to the physician for a routine health maintenance examination. She is currently preparing for an 8-km (5-mile) race, and she sprint trains twice weekly. Curing this training:
she runs 200-meter sprints in two groups of 10 sprints
separated by a 30-second rest between each sprint in a group:
and a 2-minute rest between each group of 10. After the workout her legs feel weak:
and her muscles burn and sometimes cramp. Which of the following best explains her symptoms?
A) Decreased activity of the sodium-proton antiporter, resulting in an acidic sarcoplasm
D) Regeneration of NAD+ to NADH: which produces acid
B!
During strenuous exercise - muscle undergoes anaerobic respiration - via pyruvate DH - NADH inc
NADH inc - Lactic acid inc too
37
If uk exposure and u follow up to know if disease occured in 1/2 grps (exposed v/s unexposed)
Cohort
38
If uk that the disease and exposure - u divide based on diseased v/s not diseases n check exposure significance
Case control
39
An18-year-old woman is being evaluated for amenorrhea. She has never had a menstrual period. She is 183 cm (6 ft) tall. Breast development and external genitalia are normal. There is no axillary or pubic hair. Which of the following karyotypes is most likely?
A) 45.X
B) 46,XX
C) 46,XY
D) 46,X,i(X
AIS - C
40
Post MVA - can't drink water without spilling contents. Damage to what branch?
a) Buccal branch of the facial nerve
b) Mandibular branch of the facial nerve
The facial nerve performs diverse afferent and efferent functions and has five main extracranial branches: the temporal
zygomatic, buccal marginal mandibular and cervical branches. The bucca!branch of the faciai nerve runs along the parotid duct and innervates the orbicularis oris (purses lips),
buccinator (holds cheeks flat to aid in chewing and blowing), levator labii superiors
(elevates upper lip), and anguloris (assists in smiling). Damage to the buccal branch therefore leads to difficulty in performing tasks that require closing or pursing the lips such as drinking from a glass or whistling and may also lead to the decreased ability to masticate.
The mandibular branch of the facial nerve supplies the depressor muscles of the lower lip (the depressor anguli oris, depressor fabii inferioris, and mentals). Consequently,
damage to the mandibular branch leads to the decreased ability to open the mouth or smile This patient demonstrates a decreased ability to close the mouth (purse the lips)
41
Great saphenous vein location?
Runs medially from thigh (groin) to ankle (medial malleolus)
42
Internal iliac LNs?
Internal iliac lymph nodes drain the lower rectum to the anal canal above the pectinate line, bladder middle third of the
vagina, cervix, and prostate. After reaching the internal iliac lymph nodes; the lymph will be channeled through the cisterna chyli and thoracic duct and ultimately drain into the left subclavian vein.
43
70 yr old + had chronic GI bleeding per rectum and was undergoing FOBT + now dead and autopsy of colon shows mass. Type?
Inflammatory
Tubular adenoma
MCC of chronic bleeding in oldies - CRC so B
44
hereditary spherocytosis?
AD inheritance
45
Flushing and erythema of face post drinking alcohol. Cause?
a) Alcohol dehydrogenase
b) Alcohol reductase
c) Aldehyde dehydrogenase
C
why not A? Alcohol dehydrogenase plays the primary role in the metabolism of alcohols such as ethanol, methanol, and ethylene glycol. Alcohol dehydrogenase is the target of the drug fomepizole, which is used to treat methanol or ethylene glycol poisoning
46
medical management of cholecystitis MOA?
C) Increased metabolism of bile salts
D) Inhibition of biliary cholesterol secretion
Ursodeoxycholic acid - D - mainly used as bile acid sequestrants
C - Cholestyramine - not used for this but to lower Ch.
47
Physical examination shows no abnormalities. An EGG shows a sinus rhythm of 70/min PR interval of 152 msec and QRS complex of 84 msec: there are no ectopic beats. Which of the following best represents the longest conduction time in this patient?
a) Low right atrium to bundle of His
b} Proximal bundle of His to ventricular myocardium
We see prolonged PR (>120) matlab issue in AVN
Location is A!
48
US on pg 108 Intrauterine shows fluid arnd testis. Cause?
Patent processes vaginalis
49
2-week history of painful swelling under her right arm, Physical examination shows a 2 x 1-cm tender right axillary lymph node and a
small papule on the dorsum of the right hand. A silver-stained biopsy specimen of the papule shows pleomorphic bacilli. Cause?
Bartonella hensalie
50
SOB with exertion + high BP + loud S4. Cause of C/P:
a) Impaired left ventricular relaxation
b) Increased turbulent flow across the mitral valve
c) Obstruction of the left ventricular outflow tract
Ans) A
Why not C?
Obstruction of the left ventricular outflow tract may occur in hypertrophic cardiomyopathy. Left ventricular hypertrophy due to hypertension does not typically obstruct the outflow tract.
51
This neoplasm is further typed for cell surface and intracellular markers specific for lymphocyte subsets. The neoplastic cells
do not express the following markers: CD4: CD3; surface IgM, surface IgG, cytoplasmic IgM and p-heavy chain cytoplasmic lgG: and y-heavy chain The leukemic cells express class I MHC molecules and show rearrangement of the T-lymphocyte receptor
P-chain gene D and J segments. Which of the fallowing is the normal counterpart of these malignant lymphocytes?
A) Mature immunoglobulin-secreting plasma cells in the fymph node
b) Pre-B lymphocyte progenitor of mature B lymphocytes in the bone marrow
c) T-lymphocyte thymocytes localized to the thymic cortex
C read qn carefully!
52
Cervical rib fracture damages what art?
Subclavian art
53
A24-year-old man who is comatose is admitted to the hospital because of a drug overdose and pneumonia. On admission he is intubated and mechanically ventilated. While receiving a tidal volume of 500 mL. The patient's end-expiratory pressure is +5 cm
H2Q, and his end-inspiratory airway pressure is +25 cm H20 . An esophageal balloon is inserted, and an end-inspiratory pleural pressure of +20 cm Hp is measured. Which of the following best represents this patient's respiratory system compliance?
C = 500/20
change n pr = 25-5
54
Respiratory chain enzyme studies on cultured fibroblasts show decreased complex I! activity. The most likely cause ofthese findings is a defect in which of the following processes?
A) Coupling of electron transport to proton gradient formation
B) Coupling of proton gradient to ATP synthesis
C) Oxidation of succinate to fumarate
D) Reduction of pyruvate to lactate
E) Transfer of electrons from NADH to coenzyme Q
F) Transfer of electrons from ubiquinol to cytochrome c
C!!
Review Oxidative phosphorylation
Complex 1 - NADH DH
Complex 2 - Succinate DH (Succinate to fumarate)
Complex 3 - CoQ - CytC
Complex 4 - CytC oxidase
55
Neurologic examination shows decreased pain sensation in both upper extremities and weakness and atrophy of the intrinsic muscles of both
hands. Which of the following best explains these findings?
Syringomyelia
Pain + T and atrophy as well
56
Pg 113 CT scan - crosses midline + oldie + alchoholic. Type of Hemorrhage?
SDH - dural bridging veins !!
57
Pg 134 what signifies a meal consumption v/s ghrelin conc?
Ghrelin drops right after meal concumption (C- drop and B is meal consumption)
58
DiGeorge synd is?
Reciprocal translocation
Deletion
22q11 DELETION H!!!
59
If u get bad results and pt asks u its bad right. What to do?
Do not ask how u feeling and what u think just say yes it is
60
Humoral antibody produced against many viruses following natural infection mediates protection against reinfection with the same strain primarily by which of the following mechanisms?
A) Activation of macrophages
B) Blocking of viral attachment to cell receptors
C) Inhibition of viral nucleic acid replication
D) Killing of intracellular virions
E) Prevention of release of virions from infected cell
The antibodies produced target a variety of viral particles, some of which include the proteins on the viral surface required to bind to and infect host cells. For example, influenza contains the protein hemagglutinin, which binds the sialic acid receptor on the outside of host cells and allows for viral entry. When antibodies are present to hemagglutinin, they bind to the protein and create a barricade between the ligand and receptor preventing viral attachment to ceil receptors and subsequent cell entry.
A and D --> via adaptive IS
61
Pg 149 shows gram stain of?
N.gonorrhea
Chlamydia cant gram stain rmmbr?
62
A35-year-old woman gravida 1r
para 1: comes to the physician for a follow-up examination 1 month after delivering a healthy male newborn. During her pregnancy, she was diagnosed with gestational diabetes. Her mother and sister also developed this condition during pregnancy. Today, laboratory studies show a serum glucose concentration of 100 mg/dL This patient most likely has decreased activity of which of the following enzymes?
A) D13kinase
B) Glucokinase
G) Mevalonate kinase
D) Phosphofructokinase
E) Pyruvate kinase
Glucokinase acts as a glucose sensor in hepatocytes and B cells of the pancreas. Deficiencies of the enzyme lead to MGDY, which presents with an autosomal dominant pattern of mild hyperglycemia
63
Glucosuria caused by saturation of what channels in PCT?
A) SGLT2
B) SGLT1
B!
Saturation of glucose transporter protein-2 (GLUT-2) carrier protein (Choice D) occurs after large oral glucose loads. GLUT-2 is expressed in the liver pancreas,
kidneys, and gastrointestinal tract. It functions as a glucose-sensing receptor in the liver and pancreas but plays less of a role of glucose transport in the nephron
64
An investigator is planning to create gene therapy for Leigh syndrome, which is caused by an A^G mutation in the mitochondrial tRNALeu gene. Which of the following is the most likely reason why mitochondria encode their own DNA?
Mitochondria use a non-standard genetic code - cDNA
65
A27-year-old man comes to the physician because of fever and cough for 1 month. An x-ray of the chest shows diffuse infiltrates. Tiny intracellular yeast forms are seen on direct smears, and tubercuiate macroconidia are seen after culture at room
temperature. Which of the following exposures is most consistent with this patient's illness?
A) Bird droppings
B) Desert sandstorm
C) Moldy hay
Histoplasma species on culture grows with septate mycelia and characteristic tubercuiate macroconidia. So ans is A
b - Histology reveals spherules filled with Cocciciioldes species endospores
D - Moldy hay (Choice D) is associated with hypersensitivity pneumonitis secondary to the inhalation of dust and mold spares.
66
pg 169 on effect on Betablockers on tracheal sm muscle?
Drug X on the graph is likely metoprolol. which is selective for receptors with minimal B2 activity; resulting in a slight increase in the concentration of epinephrine needed to outcompete for the binding site. Propranolol is active at both on the graph.
67
13-year-old girl 70th percentile for height and weight. Breast and pubic hair development is Tanner stage 2. Physical examination shows a 3-mm; mildly pigmented mass located in the midclavicular ^ne at the 10th rib. The mass has a smooth surface, uniform outer border and central papule. There are no other pigmented lesions.
Which of the following is the most likely diagnosis?
Accessory nipple
68
Study is conducted to determine if concomitant oral administration of ciprofloxacin and sucralfate results in a decreased plasma ciprofloxacin concentration. Twelve subjects are enrolled in the study: six receive ciprofloxacin only, and six receive both
treatments. The half-life is determined; and a 1-week washout period follows. Each subject then receives the other treatment; and half-life is measured again. Which of the following best describes the design of this study?
A) Case-control
B) Crossover
C) Prospective cohort
Ans: B
n a crossover study;
patients will be switched between treatment cohorts during the study duration. In this method;
each patient can serve as their own control. As described in the study here, a washout period is used to allow for residual effects of the prior treatment to be adequately removed from the body. Because each patient acts as their own independent control; this study design is efficient , as it requires a smaller number of patients than would a randomized controlled trial to achieve the same power.
69
Glutamate used as a Co-factor for synthesis of:
Purine
Pyramidine
IMP - A n T - purine
n the de novo synthesis of both purines and pyrimidines, ribose 5-phosphate (provided by the pentose phosphate pathway) is initially converted to 5-phospho-a-D-ribosyl 1-pyrophosphate (PRPP) by PRPP synthetase. In the first step that commits the nucleotide precursor to the purine synthesis pathway, PRPP is then converted to S'-phosphoribosylamine (PRA) by PRPP amidatransferase. In this reaction, glutamine serves as a nitrogen donor and is
converted to glutamate. PRA is ultimately converted to inosine monophosphate (IMP), which can then be converted to adenine or guanine monophosphate (AMP or GMP). AMP and GMP can then form phosphodiester bonds with other nucleotides to form DNA.
IMP. AMP, and GMP inhibit PRPP amidotransferase activity.
70
An odds ratio (OR) of 1.4 is obtained. Which of the following 95% confidence intervals for the OR is the most precise statistically significant interval?
A)-0.9 to 0.9
B) 0.9 to1.7
C) 0.93 to 1.01
D) 1.01 to 1.73
E) 1.2 to1.7
Confidence intervals are a measure of the precision of a statistical estimate. Smaller confidence intervals indicate greater precision. When interpreting an odds ratio or a relative risk, a confidence interval that does not include 1.0 indicates a statistically significant difference between the groups
71
CNA isolated from the control lymphocytes, electrophoresed on an agarose gef
and stained with ethidium bromide, shows a ladder of regularly spaced bands. When lymphocytes from the same culture are transfected so that they overexpress Gene X, which encodes a normal protein product, the cells continue to proliferate and do not
undergo any of the morphologic changes seen in the control cells. Gene X is most likely to encode which of the following?
A) BCL2 protein
B) ERB62 protein
C) p53 protein
it is found in the outer mitochondrial membrane, nuclear envelope, and endoplasmic reticulum. BCL2 functions by preventing the
oligomerization of BAX/BAK in the outer mitochondrial membrane, which would normally cause release of cytochrome c and activation of caspases in the cytoplasm via interaction with apoptotic protease activating factors.
72
AS changes?
Inc SV + Inc Myocardial Oxygen
consumption but Myocardial Oxygen Tension is dec
Adenosine (Inc ATP use) - inc
73
AG5-year-old woman with severe sensorineural hearing loss undergoes surgical placement of a cochlear implant. This neural prosthesis converts sound energy to electrical signals, which results in stimulation of which of the following structures?
A) Auditory nerve endings in the cochlea
C) Inner hair cells of the cochlea
E) Oval window of the cochlea
Now basically we have a aid that doing the electrical signal conversion for us so next step is A
(SNHL - inner hair cells are defective)
c - The oval window normally transmits mechanical vibrations to the perilymph and ultimately to the hair cells. If the hair cells are defective, oval window stimulation would not solve the
problem.
74
K+ sparing diuretic MOA?
a) Blocks basolateral K+ channels inthe collecting duct
b) Decreases the luminal permeability to Na+in the collecting duct
B! Blocks ENac - triamterene and amiloride
75
Pg 199 shows CT
Damage to hippocampus causes anterograde amnesia
Not uninhibited inappropriate behavior that's Amygdala - abv hippocampus on CT
