NBME 28 EXAM WITH ACTUAL CORRECT
QUESTIONS AND VERIFIED DETAILED
ANSWERS| CURRENTLY TESTING VERSION |
ALREADY GRADED A+|EXPERT VERIFIED
FOR GUARANTEED PASS 2026-2027
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
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
1|Page
,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 scrotal swelling and refers to
acute infection and inflammation of the epididymis. In younger males, this is commonly
secondary to sexually transmitted infections such as Chlamydia trachomatis or
Neisseria
gonorrhoeae. In older males, Escherichia coli is more common.
Renal infarction (Choice D) can cause flank pain, nausea, and vomiting, and can be due
to thromboembolic disease, renal artery dissection, or a hypercoagulable state.
However, it is rare and ureteral calculus is more common and likely in this patient.
Torsion of the testis (Choice E) occurs when the testicle twists on the spermatic cord
resulting in subsequent loss of testicular blood supply. Patients typically present with
acute, severe testicular pain, swelling, and erythema. On physical examination, the
testicle
typically demonstrates an abnormal lie (eg, transverse), extreme tenderness to
palpation, absent cremasteric reflex, and pain that does not improve with elevation of
the scrotum (as it does in epididymitis).
Educational Objective: Ureteral calculus typically presents with colicky, unilateral flank
pain radiating to the groin, along with gross or microscopic hematuria.
%3D
Next
Score Report
Lab Values
Calculator
Help
Pause
2|Page
,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
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.
Pain sensation (Choice B) is mediated by the spinothalamic pathway. The
spinothalamic pathway transmits information about pain, temperature, and crude
touch up the spinal cord to the thalamus, terminating in the primary sensory cortex.
Educational Objective: The anterior lobe of the cerebellum mediates unconscious
proprioception, whereas conscious proprioception is controlled by the dorsal column-
medial lemniscus pathway. Lesions of the anterior lobe of the cerebellum can result in
broad-
based gait ataxia.
3|Page
, %3D
Previous
Next
Score Report
Lab Values
Calculator
Help
Pause
3
Exam Section 1: Item 3 of 50
National Board of Medical Examiners®
Comprehensive Basic Science Self-Assessment
3. Moving the forearm against resistance from palm-down to palm-up (supination)
position requires the use of which of the following muscles?
A) Biceps brachii
B) Brachialis
OC) Triceps
D) Flexor carpi radialis
E) Pronator teres
A.
The biceps brachii muscle has two main actions, flexion of the elbow joint and
supination of the forearm. The biceps brachii contains two proximal heads, with the
short head attaching to the coracoid process of the scapula and the long head entering
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 causes elbow flexion. Its eccentric insertion on the
proximal radius allows for it to wind around the radius during pronation and unwind
when contracted from around the proximal radius during supination.
Incorrect Answers: B, C, D and E.
The brachialis muscle (Choice B) originates on the anterior surface of the humerus and
crosses the elbow inserting on the tuberosity of the ulna. It does not wrap around the
ulna and the ulna does not rotate. Because of this, it does not contribute to supination
or
pronation.
The triceps muscle (Choice C) serves to extend the elbow joint. Proximally, it originates
from the infraglenoid tubercle of the scapula (long head), just 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
4|Page
QUESTIONS AND VERIFIED DETAILED
ANSWERS| CURRENTLY TESTING VERSION |
ALREADY GRADED A+|EXPERT VERIFIED
FOR GUARANTEED PASS 2026-2027
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
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
1|Page
,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 scrotal swelling and refers to
acute infection and inflammation of the epididymis. In younger males, this is commonly
secondary to sexually transmitted infections such as Chlamydia trachomatis or
Neisseria
gonorrhoeae. In older males, Escherichia coli is more common.
Renal infarction (Choice D) can cause flank pain, nausea, and vomiting, and can be due
to thromboembolic disease, renal artery dissection, or a hypercoagulable state.
However, it is rare and ureteral calculus is more common and likely in this patient.
Torsion of the testis (Choice E) occurs when the testicle twists on the spermatic cord
resulting in subsequent loss of testicular blood supply. Patients typically present with
acute, severe testicular pain, swelling, and erythema. On physical examination, the
testicle
typically demonstrates an abnormal lie (eg, transverse), extreme tenderness to
palpation, absent cremasteric reflex, and pain that does not improve with elevation of
the scrotum (as it does in epididymitis).
Educational Objective: Ureteral calculus typically presents with colicky, unilateral flank
pain radiating to the groin, along with gross or microscopic hematuria.
%3D
Next
Score Report
Lab Values
Calculator
Help
Pause
2|Page
,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
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.
Pain sensation (Choice B) is mediated by the spinothalamic pathway. The
spinothalamic pathway transmits information about pain, temperature, and crude
touch up the spinal cord to the thalamus, terminating in the primary sensory cortex.
Educational Objective: The anterior lobe of the cerebellum mediates unconscious
proprioception, whereas conscious proprioception is controlled by the dorsal column-
medial lemniscus pathway. Lesions of the anterior lobe of the cerebellum can result in
broad-
based gait ataxia.
3|Page
, %3D
Previous
Next
Score Report
Lab Values
Calculator
Help
Pause
3
Exam Section 1: Item 3 of 50
National Board of Medical Examiners®
Comprehensive Basic Science Self-Assessment
3. Moving the forearm against resistance from palm-down to palm-up (supination)
position requires the use of which of the following muscles?
A) Biceps brachii
B) Brachialis
OC) Triceps
D) Flexor carpi radialis
E) Pronator teres
A.
The biceps brachii muscle has two main actions, flexion of the elbow joint and
supination of the forearm. The biceps brachii contains two proximal heads, with the
short head attaching to the coracoid process of the scapula and the long head entering
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 causes elbow flexion. Its eccentric insertion on the
proximal radius allows for it to wind around the radius during pronation and unwind
when contracted from around the proximal radius during supination.
Incorrect Answers: B, C, D and E.
The brachialis muscle (Choice B) originates on the anterior surface of the humerus and
crosses the elbow inserting on the tuberosity of the ulna. It does not wrap around the
ulna and the ulna does not rotate. Because of this, it does not contribute to supination
or
pronation.
The triceps muscle (Choice C) serves to extend the elbow joint. Proximally, it originates
from the infraglenoid tubercle of the scapula (long head), just 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
4|Page
