NBME 28
1
Exam Section 1: Item 1 of fifty
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
1. A 25-12 months-old man is brought to the emergency branch due to extreme abdominal
pain, nausea, and vomiting for 1 hour. The ache originates within the left flank and radiates
to his groin. His pulse is one hundred/min, respirations are 18/min, and blood strain is
a hundred and fifty/a hundred mm Hg. Physical exam suggests 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 terrible. Which of the following first-rate explains those findings?
A) Colon neoplasm
B) Diverticulitis
C) Epididymitis
D) Renal infarction
E) Torsion of the testis
F) Ureteral calculus - ANS-F.
Ureteral calculus usually gives with colicky, unilateral flank ache radiating to the groin, and
with gross or microscopic hematuria. Pain can be sizable enough to cause nausea, as in this
situation. The not unusual types of urinary tract calculi are calcium oxalate or
phosphate, ammonium magnesium phosphate, uric acid, and cystine. On urinalysis, crimson
blood cells without casts are not unusual. Fever, dysuria, and pyuria would now not be
predicted unless there was a concomitant contamination. Treatment for ureteral calculus is
symptomatic with pain control and nausea remedy. Most ureteral calculi skip spontaneously
after a length of commentary for patients with well-controlled pain and no signs of sepsis or
contamination. Stone elimination by means of surprise wave lithotripsy or endoscopic
elimination is an
option for patients requiring emergency remedy. It is also an alternative for patients with
persistent obstruction, out of control signs, or failure of stone progression. In widespread,
stones smaller than 5 mm will skip without operative assistance. Obstructing stones can also
require transient placement of a ureteral stent to prevent hydronephrosis and renal
parenchymal harm.
Incorrect Answers: A, B, C, D, and E.
Colon neoplasm (Choice A) could be not likely in an otherwise healthy young patient with no
family history of polyposis syndromes and acute, intense, flank ache. It could generally
present with insidious weight reduction, anemia, constipation, or blood per rectum. In
addition, test for stool for occult blood is bad, making this diagnosis not likely.
Diverticulitis (Choice B) can present with left decrease quadrant belly pain and tenderness
however might be much less abrupt in presentation and generally present with fever,
diarrhea, and hyperactive bowel sounds. It might be not going to cause flank pain.
Epididymitis (Choice C) is a commonplace motive 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 varieties of sensory statistics is compromised by using lesions of
the shape at website X within the image shown?
A) Conscious proprioception
B) Pain sensation
C) Two-point discrimination
D) Unconscious proprioception
E) Vibration sense - ANS-D.
The anterior lobe of the cerebellum (categorised X, pictured in pass-section as an arborized
brain place posterior to the brainstem and anterior to the number one fissure of the
cerebellum) mediates unconscious proprioception. The anterior lobe of the cerebellum
receives
records from the spinocerebellar tract approximately proprioception, or frame position, that is
accumulated from muscle stretch and tension receptors on the ipsilateral facet of the body.
This proprioceptive statistics is transmitted out of doors of aware consciousness. The deep
cerebellar nuclei use this proprioceptive records to govern motor gaining knowledge of,
movement course modifications, and stability. Damage to the anterior lobe of the cerebellum,
which generally happens in persistent alcoholism, may also result in broad-based gait ataxia.
Incorrect Answers: A, B, C, and E.
Conscious proprioception (Choice A), two-point discrimination (Choice C), and vibration
experience (Choice E) are mediated with the aid of the dorsal column-medial lemniscus
pathway, which relays this sensory facts up the spinal wire to the thalamus and terminates
within the
number one sensory cortex in the parietal lobe. The cortex is a excessive-order mind
location concerned in several aware mind features, which reflects this pathway's mediation
of the conscious (as opposed to subconscious) consciousness of proprioception.
Pain sensation (Choice B) is mediated with the aid of the spinothalamic pathway. The
spinothalamic pathway transmits information approximately ache, temperature, and crude
contact up the spinal cord to the thalamus, terminating inside the number one sensory
cortex.
Educational Objective: The anterior lobe of the cerebellum mediates subconscious
proprioception, whereas aware proprioception is managed by means of the dorsal
column-medial lemniscus pathway. Lesions of the anterior lobe of the cerebellum can result
in vast-
based totally gait ataxia.
%3D
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3
Exam Section 1: Item 3 of 50
National Board of Medical Examiners®
Comprehensive Basic Science Self-Assessment
3. Moving the forearm towards resistance from palm-right down to palm-up (supination) role
requires using which of the subsequent muscle groups?
A) Biceps brachii
,B) Brachialis
OC) Triceps
D) Flexor carpi radialis
E) Pronator teres - ANS-A.
The biceps brachii muscle has foremost movements, flexion of the elbow joint and
supination of the forearm. The biceps brachii includes two proximal heads, with the quick
head attaching to the coracoid system of the scapula and the lengthy head getting into the
shoulder
joint and attaching to the supraglenoid tubercle. The distal biceps tendon inserts on the
bicipital tuberosity of the proximal radius. Because of its orientation crossing the elbow joint,
contraction of this muscle reasons elbow flexion. Its eccentric insertion at the
proximal radius lets in for it to wind around the radius all through pronation and unwind while
shrunk from across the proximal radius throughout supination.
Incorrect Answers: B, C, D and E.
The brachialis muscle (Choice B) originates at the anterior surface of the humerus and
crosses the elbow putting at the tuberosity of the ulna. It does no longer wrap across the
ulna and the ulna does now not rotate. Because of this, it does not contribute to supination
or
pronation.
The triceps muscle (Choice C) serves to increase the elbow joint. Proximally, it originates
from the infraglenoid tubercle of the scapula (long head), simply proximal to the radial
groove (lateral head), and just distal to the radial groove (medial head). Distally, it inserts on
the olecranon process of the ulna. Contraction of this muscle extends the elbow and does
not contribute to rotation.
Flexor carpi radialis (Choice D) originates at the medial epicondyle of the humerus and
inserts on the second and 1/3 metacarpal bones. This permits for flexion of the wrist.
Pronator teres (Choice E) is a muscle of the proximal forearm that extends from the medial
supracondylar ridge of the humerus and inserts on the lateral factor of the radius.
Contraction alongside this axis will sell pronation, now not supination.
Educational Objective: The biceps brachii
4
Exam Section 1: Item 4 of fifty
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
four. A 35-year-old guy is admitted to the medical institution due to a five-day history of fever
and dyspnea. He underwent a bone marrow transplantation 6 months in the past; the
manner changed into complicated by extreme graft-versus-host disease. His temperature is
38°C
(one hundred.4°F), and respirations are 30/min. Scattered crackles are heard on
auscultation of the chest. A chest x-ray indicates patchy infiltrates. A transbronchial biopsy
specimen indicates findings steady with cytomegalovirus infection. Intravenous
administration of
ganciclovir is started. This drug interferes with the function of which of the subsequent
enzymes?
A) DNA polymerase
B) Integrase
C) Reverse transcriptase
, D) RNA polymerase
E) Thymidine kinase - ANS-A.
Cytomegalovirus (CMV), additionally known as human herpesvirus five (HHV-5), is an
opportunistic contamination usually happening in immunocompromised patients with
solid-organ or allogeneic bone marrow transplantation, intense ulcerative colitis, or HIV/AIDS
infection. It
may be transmitted thru more than one modes, inclusive of sexual touch, urine, respiratory
droplets, and to a fetus thru the placenta. It can motive a selection of displays, inclusive of
mononucleosis in immunocompetent sufferers, and retinitis, esophagitis, and pneumonia
in immunocompromised patients. Treatment for all human herpesvirus infections entails
tablets that inhibit viral DNA polymerase, classically by using guanosine analogs including
acyclovir, valacyclovir, and famciclovir. Prior to exerting their antiviral outcomes, most
guanosine analogs have to be phosphorylated by means of the viral enzyme thymidine
kinase. They are then capable of inhibit the viral DNA polymerase with the aid of terminating
the nascent DNA chain at some stage in replication. These drugs are powerful towards
herpes simplex virus and varicella
zoster virus, weakly powerful towards Épstein-Barr virus, and no longer powerful in
opposition to CMV, which does no longer have the vital thymidine kinase wished for
phosphorylation. However, it does have the important phosphorylating enzyme to prompt
ganciclovir, any other
guanosine analog that inhibits DNA polymerase, and as a result this is an powerful anti-viral
treatment for CMV.
Incorrect Answers: B, C, D, and E.
Integrase inhibitors (Choice B) save you integration of proviral DNA into the host genome.
They are a element of the surprisingly lively anti-retroviral therapy applied in the remedy of
HIV.
Reverse transcriptase (Choice C) transcribes DNA from viral MRNA for incorporation into the
host mobile genome. This enzyme is inhibited with the aid of both nucleoside opposite
transcriptase inhibitors, which include abacavir and d
five
Exam Section 1: Item five of fifty
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
two hundred-
a hundred-
M
M
25 27 1 3 5 7 9 eleven 13 15 17 19 21 23 25 2713 5
Cycle (day)
M = menstruation
5. The graph shows changes in serum estradiol awareness all through a normal menstrual
cycle. Which of the subsequent ovarian cells is in the main liable for the aromatization of
androstenedione to estradiol at the time indicated via the arrow?
A) Granulosa
B) Luteal
C) Stromal
D) Theca externa
1
Exam Section 1: Item 1 of fifty
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
1. A 25-12 months-old man is brought to the emergency branch due to extreme abdominal
pain, nausea, and vomiting for 1 hour. The ache originates within the left flank and radiates
to his groin. His pulse is one hundred/min, respirations are 18/min, and blood strain is
a hundred and fifty/a hundred mm Hg. Physical exam suggests 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 terrible. Which of the following first-rate explains those findings?
A) Colon neoplasm
B) Diverticulitis
C) Epididymitis
D) Renal infarction
E) Torsion of the testis
F) Ureteral calculus - ANS-F.
Ureteral calculus usually gives with colicky, unilateral flank ache radiating to the groin, and
with gross or microscopic hematuria. Pain can be sizable enough to cause nausea, as in this
situation. The not unusual types of urinary tract calculi are calcium oxalate or
phosphate, ammonium magnesium phosphate, uric acid, and cystine. On urinalysis, crimson
blood cells without casts are not unusual. Fever, dysuria, and pyuria would now not be
predicted unless there was a concomitant contamination. Treatment for ureteral calculus is
symptomatic with pain control and nausea remedy. Most ureteral calculi skip spontaneously
after a length of commentary for patients with well-controlled pain and no signs of sepsis or
contamination. Stone elimination by means of surprise wave lithotripsy or endoscopic
elimination is an
option for patients requiring emergency remedy. It is also an alternative for patients with
persistent obstruction, out of control signs, or failure of stone progression. In widespread,
stones smaller than 5 mm will skip without operative assistance. Obstructing stones can also
require transient placement of a ureteral stent to prevent hydronephrosis and renal
parenchymal harm.
Incorrect Answers: A, B, C, D, and E.
Colon neoplasm (Choice A) could be not likely in an otherwise healthy young patient with no
family history of polyposis syndromes and acute, intense, flank ache. It could generally
present with insidious weight reduction, anemia, constipation, or blood per rectum. In
addition, test for stool for occult blood is bad, making this diagnosis not likely.
Diverticulitis (Choice B) can present with left decrease quadrant belly pain and tenderness
however might be much less abrupt in presentation and generally present with fever,
diarrhea, and hyperactive bowel sounds. It might be not going to cause flank pain.
Epididymitis (Choice C) is a commonplace motive 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 varieties of sensory statistics is compromised by using lesions of
the shape at website X within the image shown?
A) Conscious proprioception
B) Pain sensation
C) Two-point discrimination
D) Unconscious proprioception
E) Vibration sense - ANS-D.
The anterior lobe of the cerebellum (categorised X, pictured in pass-section as an arborized
brain place posterior to the brainstem and anterior to the number one fissure of the
cerebellum) mediates unconscious proprioception. The anterior lobe of the cerebellum
receives
records from the spinocerebellar tract approximately proprioception, or frame position, that is
accumulated from muscle stretch and tension receptors on the ipsilateral facet of the body.
This proprioceptive statistics is transmitted out of doors of aware consciousness. The deep
cerebellar nuclei use this proprioceptive records to govern motor gaining knowledge of,
movement course modifications, and stability. Damage to the anterior lobe of the cerebellum,
which generally happens in persistent alcoholism, may also result in broad-based gait ataxia.
Incorrect Answers: A, B, C, and E.
Conscious proprioception (Choice A), two-point discrimination (Choice C), and vibration
experience (Choice E) are mediated with the aid of the dorsal column-medial lemniscus
pathway, which relays this sensory facts up the spinal wire to the thalamus and terminates
within the
number one sensory cortex in the parietal lobe. The cortex is a excessive-order mind
location concerned in several aware mind features, which reflects this pathway's mediation
of the conscious (as opposed to subconscious) consciousness of proprioception.
Pain sensation (Choice B) is mediated with the aid of the spinothalamic pathway. The
spinothalamic pathway transmits information approximately ache, temperature, and crude
contact up the spinal cord to the thalamus, terminating inside the number one sensory
cortex.
Educational Objective: The anterior lobe of the cerebellum mediates subconscious
proprioception, whereas aware proprioception is managed by means of the dorsal
column-medial lemniscus pathway. Lesions of the anterior lobe of the cerebellum can result
in vast-
based totally gait ataxia.
%3D
Previous
Next
3
Exam Section 1: Item 3 of 50
National Board of Medical Examiners®
Comprehensive Basic Science Self-Assessment
3. Moving the forearm towards resistance from palm-right down to palm-up (supination) role
requires using which of the subsequent muscle groups?
A) Biceps brachii
,B) Brachialis
OC) Triceps
D) Flexor carpi radialis
E) Pronator teres - ANS-A.
The biceps brachii muscle has foremost movements, flexion of the elbow joint and
supination of the forearm. The biceps brachii includes two proximal heads, with the quick
head attaching to the coracoid system of the scapula and the lengthy head getting into the
shoulder
joint and attaching to the supraglenoid tubercle. The distal biceps tendon inserts on the
bicipital tuberosity of the proximal radius. Because of its orientation crossing the elbow joint,
contraction of this muscle reasons elbow flexion. Its eccentric insertion at the
proximal radius lets in for it to wind around the radius all through pronation and unwind while
shrunk from across the proximal radius throughout supination.
Incorrect Answers: B, C, D and E.
The brachialis muscle (Choice B) originates at the anterior surface of the humerus and
crosses the elbow putting at the tuberosity of the ulna. It does no longer wrap across the
ulna and the ulna does now not rotate. Because of this, it does not contribute to supination
or
pronation.
The triceps muscle (Choice C) serves to increase the elbow joint. Proximally, it originates
from the infraglenoid tubercle of the scapula (long head), simply proximal to the radial
groove (lateral head), and just distal to the radial groove (medial head). Distally, it inserts on
the olecranon process of the ulna. Contraction of this muscle extends the elbow and does
not contribute to rotation.
Flexor carpi radialis (Choice D) originates at the medial epicondyle of the humerus and
inserts on the second and 1/3 metacarpal bones. This permits for flexion of the wrist.
Pronator teres (Choice E) is a muscle of the proximal forearm that extends from the medial
supracondylar ridge of the humerus and inserts on the lateral factor of the radius.
Contraction alongside this axis will sell pronation, now not supination.
Educational Objective: The biceps brachii
4
Exam Section 1: Item 4 of fifty
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
four. A 35-year-old guy is admitted to the medical institution due to a five-day history of fever
and dyspnea. He underwent a bone marrow transplantation 6 months in the past; the
manner changed into complicated by extreme graft-versus-host disease. His temperature is
38°C
(one hundred.4°F), and respirations are 30/min. Scattered crackles are heard on
auscultation of the chest. A chest x-ray indicates patchy infiltrates. A transbronchial biopsy
specimen indicates findings steady with cytomegalovirus infection. Intravenous
administration of
ganciclovir is started. This drug interferes with the function of which of the subsequent
enzymes?
A) DNA polymerase
B) Integrase
C) Reverse transcriptase
, D) RNA polymerase
E) Thymidine kinase - ANS-A.
Cytomegalovirus (CMV), additionally known as human herpesvirus five (HHV-5), is an
opportunistic contamination usually happening in immunocompromised patients with
solid-organ or allogeneic bone marrow transplantation, intense ulcerative colitis, or HIV/AIDS
infection. It
may be transmitted thru more than one modes, inclusive of sexual touch, urine, respiratory
droplets, and to a fetus thru the placenta. It can motive a selection of displays, inclusive of
mononucleosis in immunocompetent sufferers, and retinitis, esophagitis, and pneumonia
in immunocompromised patients. Treatment for all human herpesvirus infections entails
tablets that inhibit viral DNA polymerase, classically by using guanosine analogs including
acyclovir, valacyclovir, and famciclovir. Prior to exerting their antiviral outcomes, most
guanosine analogs have to be phosphorylated by means of the viral enzyme thymidine
kinase. They are then capable of inhibit the viral DNA polymerase with the aid of terminating
the nascent DNA chain at some stage in replication. These drugs are powerful towards
herpes simplex virus and varicella
zoster virus, weakly powerful towards Épstein-Barr virus, and no longer powerful in
opposition to CMV, which does no longer have the vital thymidine kinase wished for
phosphorylation. However, it does have the important phosphorylating enzyme to prompt
ganciclovir, any other
guanosine analog that inhibits DNA polymerase, and as a result this is an powerful anti-viral
treatment for CMV.
Incorrect Answers: B, C, D, and E.
Integrase inhibitors (Choice B) save you integration of proviral DNA into the host genome.
They are a element of the surprisingly lively anti-retroviral therapy applied in the remedy of
HIV.
Reverse transcriptase (Choice C) transcribes DNA from viral MRNA for incorporation into the
host mobile genome. This enzyme is inhibited with the aid of both nucleoside opposite
transcriptase inhibitors, which include abacavir and d
five
Exam Section 1: Item five of fifty
National Board of Medical Examiners'
Comprehensive Basic Science Self-Assessment
two hundred-
a hundred-
M
M
25 27 1 3 5 7 9 eleven 13 15 17 19 21 23 25 2713 5
Cycle (day)
M = menstruation
5. The graph shows changes in serum estradiol awareness all through a normal menstrual
cycle. Which of the subsequent ovarian cells is in the main liable for the aromatization of
androstenedione to estradiol at the time indicated via the arrow?
A) Granulosa
B) Luteal
C) Stromal
D) Theca externa
