NBME CBSE Exam – 50 Verified Questions
and Answers2025/2026 | Medical Board
Practice Test
1
Exam Section 1: Item 1 of 50
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
1. A 25-year-old man is brought to the emergency department because of severe abdominal pain,
nausea, and vomiting for 1 hour. The pain originates in the left flank and radiates to his groin. His pulse
is 100/min, respirations are 18/min, and blood pressure is
150/100 mm Hg. Physical examination shows tenderness of the left flank and the left lower quadrant of
the abdomen. Bowel sounds are mildly hypoactive. Test of the stool for occult blood is negative. Which
of the following best explains these findings?
A) Colon neoplasm
B) Diverticulitis
C) Epididymitis
D) Renal infarction
E) Torsion of the testis
F) Ureteral calculus - CORRECT ANSWER-F.
Ureteral calculus typically presents with colicky, unilateral flank pain radiating to the groin, and with
gross or microscopic hematuria. Pain may be significant enough to trigger nausea, as in this case. The
common types of urinary tract calculi are calcium oxalate or
phosphate, ammonium magnesium phosphate, uric acid, and cystine. On urinalysis, red blood cells
without casts are common. Fever, dysuria, and pyuria would not be expected unless there was a
concomitant infection. Treatment for ureteral calculus is
symptomatic with pain control and nausea relief. Most ureteral calculi pass spontaneously after a period
of observation for patients with well-controlled pain and no signs of sepsis or infection. Stone removal
by shock wave lithotripsy or endoscopic removal is an
option for patients requiring emergency therapy. It is also an option for patients with persistent
obstruction, uncontrolled symptoms, or failure of stone progression. In general, stones smaller than 5
mm will pass without operative assistance. Obstructing stones may
,require temporary placement of a ureteral stent to prevent hydronephrosis and renal parenchymal
injury.
Incorrect Answers: A, B, C, D, and E.
Colon neoplasm (Choice A) would be unlikely in an otherwise healthy young patient with no family
history of polyposis syndromes and acute, severe, flank pain. It would typically present with insidious
weight loss, anemia, constipation, or blood per rectum. In
addition, test for stool for occult blood is negative, making this diagnosis unlikely.
Diverticulitis (Choice B) can present with left lower quadrant abdominal pain and tenderness but would
be less abrupt in presentation and typically present with fever, diarrhea, and hyperactive bowel sounds.
It would be unlikely to cause flank pain.
Epididymitis (Choice C) is a common cause of painful scrot
2
Exam Section 1: Item 2 of 50
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
2. Which of the following types of sensory information is compromised by lesions of the structure at site
X in the photograph shown?
A) Conscious proprioception
B) Pain sensation
C) Two-point discrimination
D) Unconscious proprioception
E) Vibration sense - CORRECT ANSWER-D.
The anterior lobe of the cerebellum (labeled X, pictured in cross-section as an arborized brain area
posterior to the brainstem and anterior to the primary fissure of the cerebellum) mediates unconscious
proprioception. The anterior lobe of the cerebellum receives
information from the spinocerebellar tract about proprioception, or body position, that is gathered from
muscle stretch and tension receptors on the ipsilateral side of the body. This proprioceptive information
is transmitted outside of conscious awareness. The deep
cerebellar nuclei use this proprioceptive information to control motor learning, movement course
changes, and balance. Damage to the anterior lobe of the cerebellum, which commonly occurs in
chronic alcoholism, may lead to broad-based gait ataxia.
Incorrect Answers: A, B, C, and E.
,Conscious proprioception (Choice A), two-point discrimination (Choice C), and vibration sense (Choice E)
are mediated by the dorsal column-medial lemniscus pathway, which relays this sensory information up
the spinal cord to the thalamus and terminates in the
primary sensory cortex in the parietal lobe. The cortex is a high-order brain area involved in several
conscious brain functions, which reflects this pathway's mediation of the conscious (rather than
unconscious) awareness of proprioception.
Painbsensationb(ChoicebB)bisbmediatedbbybthebspinothalamicbpathway.bThebspinothalamicbpathwaybtrans
mitsbinformationbaboutbpain,btemperature,bandbcrudebtouchbupbthebspinalbcordbtobthebthalamus,btermin
atingbinbthebprimarybsensorybcortex.
EducationalbObjective:bThebanteriorblobebofbthebcerebellumbmediatesbunconsciousbproprioception,bwhe
reasbconsciousbproprioceptionbisbcontrolledbbybthebdorsalbcolumn-
medialblemniscusbpathway.bLesionsbofbthebanteriorblobebofbthebcerebellumbcanbresultbinbbroad-
basedbgaitbataxia.
%3D
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ExambSectionb1:bItemb3bofb50
NationalbBoardbofbMedicalbExaminers®
ComprehensivebBasicbSciencebSelf-Assessment
3.bMovingbthebforearmbagainstbresistancebfrombpalm-downbtobpalm-
upb(supination)bpositionbrequiresbthebusebofbwhichbofbthebfollowingbmuscles?
A)bBicepsbbrachii
B)bBrachialis
OC)bTriceps
D)bFlexorbcarpibradialis
E)bPronatorbteresb-bCORRECTbANSWER-A.
Thebbicepsbbrachiibmusclebhasbtwobmainbactions,bflexionbofbthebelbowbjointbandbsupinationbofbthebforea
rm.bThebbicepsbbrachiibcontainsbtwobproximalbheads,bwithbthebshortbheadbattachingbtobthebcoracoidbpro
cessbofbthebscapulabandbtheblongbheadbenteringbthebshoulder
, jointbandbattachingbtobthebsupraglenoidbtubercle.bThebdistalbbicepsbtendonbinsertsbonbthebbicipitalbtuber
ositybofbthebproximalbradius.bBecausebofbitsborientationbcrossingbthebelbowbjoint,bcontractionbofbthisbmu
sclebcausesbelbowbflexion.bItsbeccentricbinsertionbonbthe
proximalbradiusballowsbforbitbtobwindbaroundbthebradiusbduringbpronationbandbunwindbwhenbcontractedb
frombaroundbthebproximalbradiusbduringbsupination.
IncorrectbAnswers:bB,bC,bDbandbE.
Thebbrachialisbmuscleb(ChoicebB)boriginatesbonbthebanteriorbsurfacebofbthebhumerusbandbcrossesbthebelb
owbinsertingbonbthebtuberositybofbthebulna.bItbdoesbnotbwrapbaroundbthebulnabandbthebulnabdoesbnotbrot
ate.bBecausebofbthis,bitbdoesbnotbcontributebtobsupinationbor
pronation.
Thebtricepsbmuscleb(ChoicebC)bservesbtobextendbthebelbowbjoint.bProximally,bitboriginatesbfrombthebinfra
glenoidbtuberclebofbthebscapulab(longbhead),bjustbproximalbtobthebradialbgrooveb(lateralbhead),bandbjustb
distalbtobthebradialbgrooveb(medialbhead).bDistally,bitbinsertsbon
thebolecranonbprocessbofbthebulna.bContractionbofbthisbmusclebextendsbthebelbowbandbdoesbnotbcontrib
utebtobrotation.
Flexorbcarpibradialisb(ChoicebD)boriginatesbonbthebmedialbepicondylebofbthebhumerusbandbinsertsbonbtheb
secondbandbthirdbmetacarpalbbones.bThisballowsbforbflexionbofbthebwrist.
Pronatorbteresb(ChoicebE)bisbabmusclebofbthebproximalbforearmbthatbextendsbfrombthebmedialbsupracond
ylarbridgebofbthebhumerusbandbinsertsbonbtheblateralbaspectbofbthebradius.bContractionbalongbthisbaxisbwi
llbpromotebpronation,bnotbsupination.
EducationalbObjective:bThebbicepsbbrachii
4
ExambSectionb1:bItemb4bofb50
NationalbBoardbofbMedicalbExaminers'
ComprehensivebBasicbSciencebSelf-Assessment
4.bAb35-year-oldbmanbisbadmittedbtobthebhospitalbbecausebofbab5-
daybhistorybofbfeverbandbdyspnea.bHebunderwentbabbonebmarrowbtransplantationb6bmonthsbago;bthebpr
ocedurebwasbcomplicatedbbybseverebgraft-versus-hostbdisease.bHisbtemperaturebisb38°C
(100.4°F),bandbrespirationsbareb30/min.bScatteredbcracklesbarebheardbonbauscultationbofbthebchest.bAbch
estbx-
raybshowsbpatchybinfiltrates.bAbtransbronchialbbiopsybspecimenbshowsbfindingsbconsistentbwithbcytomeg
alovirusbinfection.bIntravenousbadministrationbof
ganciclovirbisbbegun.bThisbdrugbinterferesbwithbthebfunctionbofbwhichbofbthebfollowingbenzymes?
and Answers2025/2026 | Medical Board
Practice Test
1
Exam Section 1: Item 1 of 50
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
1. A 25-year-old man is brought to the emergency department because of severe abdominal pain,
nausea, and vomiting for 1 hour. The pain originates in the left flank and radiates to his groin. His pulse
is 100/min, respirations are 18/min, and blood pressure is
150/100 mm Hg. Physical examination shows tenderness of the left flank and the left lower quadrant of
the abdomen. Bowel sounds are mildly hypoactive. Test of the stool for occult blood is negative. Which
of the following best explains these findings?
A) Colon neoplasm
B) Diverticulitis
C) Epididymitis
D) Renal infarction
E) Torsion of the testis
F) Ureteral calculus - CORRECT ANSWER-F.
Ureteral calculus typically presents with colicky, unilateral flank pain radiating to the groin, and with
gross or microscopic hematuria. Pain may be significant enough to trigger nausea, as in this case. The
common types of urinary tract calculi are calcium oxalate or
phosphate, ammonium magnesium phosphate, uric acid, and cystine. On urinalysis, red blood cells
without casts are common. Fever, dysuria, and pyuria would not be expected unless there was a
concomitant infection. Treatment for ureteral calculus is
symptomatic with pain control and nausea relief. Most ureteral calculi pass spontaneously after a period
of observation for patients with well-controlled pain and no signs of sepsis or infection. Stone removal
by shock wave lithotripsy or endoscopic removal is an
option for patients requiring emergency therapy. It is also an option for patients with persistent
obstruction, uncontrolled symptoms, or failure of stone progression. In general, stones smaller than 5
mm will pass without operative assistance. Obstructing stones may
,require temporary placement of a ureteral stent to prevent hydronephrosis and renal parenchymal
injury.
Incorrect Answers: A, B, C, D, and E.
Colon neoplasm (Choice A) would be unlikely in an otherwise healthy young patient with no family
history of polyposis syndromes and acute, severe, flank pain. It would typically present with insidious
weight loss, anemia, constipation, or blood per rectum. In
addition, test for stool for occult blood is negative, making this diagnosis unlikely.
Diverticulitis (Choice B) can present with left lower quadrant abdominal pain and tenderness but would
be less abrupt in presentation and typically present with fever, diarrhea, and hyperactive bowel sounds.
It would be unlikely to cause flank pain.
Epididymitis (Choice C) is a common cause of painful scrot
2
Exam Section 1: Item 2 of 50
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
2. Which of the following types of sensory information is compromised by lesions of the structure at site
X in the photograph shown?
A) Conscious proprioception
B) Pain sensation
C) Two-point discrimination
D) Unconscious proprioception
E) Vibration sense - CORRECT ANSWER-D.
The anterior lobe of the cerebellum (labeled X, pictured in cross-section as an arborized brain area
posterior to the brainstem and anterior to the primary fissure of the cerebellum) mediates unconscious
proprioception. The anterior lobe of the cerebellum receives
information from the spinocerebellar tract about proprioception, or body position, that is gathered from
muscle stretch and tension receptors on the ipsilateral side of the body. This proprioceptive information
is transmitted outside of conscious awareness. The deep
cerebellar nuclei use this proprioceptive information to control motor learning, movement course
changes, and balance. Damage to the anterior lobe of the cerebellum, which commonly occurs in
chronic alcoholism, may lead to broad-based gait ataxia.
Incorrect Answers: A, B, C, and E.
,Conscious proprioception (Choice A), two-point discrimination (Choice C), and vibration sense (Choice E)
are mediated by the dorsal column-medial lemniscus pathway, which relays this sensory information up
the spinal cord to the thalamus and terminates in the
primary sensory cortex in the parietal lobe. The cortex is a high-order brain area involved in several
conscious brain functions, which reflects this pathway's mediation of the conscious (rather than
unconscious) awareness of proprioception.
Painbsensationb(ChoicebB)bisbmediatedbbybthebspinothalamicbpathway.bThebspinothalamicbpathwaybtrans
mitsbinformationbaboutbpain,btemperature,bandbcrudebtouchbupbthebspinalbcordbtobthebthalamus,btermin
atingbinbthebprimarybsensorybcortex.
EducationalbObjective:bThebanteriorblobebofbthebcerebellumbmediatesbunconsciousbproprioception,bwhe
reasbconsciousbproprioceptionbisbcontrolledbbybthebdorsalbcolumn-
medialblemniscusbpathway.bLesionsbofbthebanteriorblobebofbthebcerebellumbcanbresultbinbbroad-
basedbgaitbataxia.
%3D
Previous
Next
3
ExambSectionb1:bItemb3bofb50
NationalbBoardbofbMedicalbExaminers®
ComprehensivebBasicbSciencebSelf-Assessment
3.bMovingbthebforearmbagainstbresistancebfrombpalm-downbtobpalm-
upb(supination)bpositionbrequiresbthebusebofbwhichbofbthebfollowingbmuscles?
A)bBicepsbbrachii
B)bBrachialis
OC)bTriceps
D)bFlexorbcarpibradialis
E)bPronatorbteresb-bCORRECTbANSWER-A.
Thebbicepsbbrachiibmusclebhasbtwobmainbactions,bflexionbofbthebelbowbjointbandbsupinationbofbthebforea
rm.bThebbicepsbbrachiibcontainsbtwobproximalbheads,bwithbthebshortbheadbattachingbtobthebcoracoidbpro
cessbofbthebscapulabandbtheblongbheadbenteringbthebshoulder
, jointbandbattachingbtobthebsupraglenoidbtubercle.bThebdistalbbicepsbtendonbinsertsbonbthebbicipitalbtuber
ositybofbthebproximalbradius.bBecausebofbitsborientationbcrossingbthebelbowbjoint,bcontractionbofbthisbmu
sclebcausesbelbowbflexion.bItsbeccentricbinsertionbonbthe
proximalbradiusballowsbforbitbtobwindbaroundbthebradiusbduringbpronationbandbunwindbwhenbcontractedb
frombaroundbthebproximalbradiusbduringbsupination.
IncorrectbAnswers:bB,bC,bDbandbE.
Thebbrachialisbmuscleb(ChoicebB)boriginatesbonbthebanteriorbsurfacebofbthebhumerusbandbcrossesbthebelb
owbinsertingbonbthebtuberositybofbthebulna.bItbdoesbnotbwrapbaroundbthebulnabandbthebulnabdoesbnotbrot
ate.bBecausebofbthis,bitbdoesbnotbcontributebtobsupinationbor
pronation.
Thebtricepsbmuscleb(ChoicebC)bservesbtobextendbthebelbowbjoint.bProximally,bitboriginatesbfrombthebinfra
glenoidbtuberclebofbthebscapulab(longbhead),bjustbproximalbtobthebradialbgrooveb(lateralbhead),bandbjustb
distalbtobthebradialbgrooveb(medialbhead).bDistally,bitbinsertsbon
thebolecranonbprocessbofbthebulna.bContractionbofbthisbmusclebextendsbthebelbowbandbdoesbnotbcontrib
utebtobrotation.
Flexorbcarpibradialisb(ChoicebD)boriginatesbonbthebmedialbepicondylebofbthebhumerusbandbinsertsbonbtheb
secondbandbthirdbmetacarpalbbones.bThisballowsbforbflexionbofbthebwrist.
Pronatorbteresb(ChoicebE)bisbabmusclebofbthebproximalbforearmbthatbextendsbfrombthebmedialbsupracond
ylarbridgebofbthebhumerusbandbinsertsbonbtheblateralbaspectbofbthebradius.bContractionbalongbthisbaxisbwi
llbpromotebpronation,bnotbsupination.
EducationalbObjective:bThebbicepsbbrachii
4
ExambSectionb1:bItemb4bofb50
NationalbBoardbofbMedicalbExaminers'
ComprehensivebBasicbSciencebSelf-Assessment
4.bAb35-year-oldbmanbisbadmittedbtobthebhospitalbbecausebofbab5-
daybhistorybofbfeverbandbdyspnea.bHebunderwentbabbonebmarrowbtransplantationb6bmonthsbago;bthebpr
ocedurebwasbcomplicatedbbybseverebgraft-versus-hostbdisease.bHisbtemperaturebisb38°C
(100.4°F),bandbrespirationsbareb30/min.bScatteredbcracklesbarebheardbonbauscultationbofbthebchest.bAbch
estbx-
raybshowsbpatchybinfiltrates.bAbtransbronchialbbiopsybspecimenbshowsbfindingsbconsistentbwithbcytomeg
alovirusbinfection.bIntravenousbadministrationbof
ganciclovirbisbbegun.bThisbdrugbinterferesbwithbthebfunctionbofbwhichbofbthebfollowingbenzymes?
