USMLE
Step 1
Sample Items
A 32-year-old construction
worker arrives in the emergency department after an accident on
the job. The tendon of the biceps brachii at the elbow has been
severed by a laceration that extends 2 cm medially from the
tendon. Which of the following structures is likely to have been
injured by medial extension of the laceration?
 |
|
|
| (A) |
|
Brachial artery |
| (B) |
|
Musculocutaneous nerve |
| (C) |
|
Profunda brachii artery |
| (D) |
|
Radial nerve |
| (E) |
|
Ulnar nerve |
A 52-year-old man presents to his physician
after a community health screening test reveals a fasting glucose
of 170 mg/dL. Physical examination is remarkable for bronze skin
pigmentation, hepatomegaly, splenomegaly, and limitation of
motion in the second and third metacarpophalangeal joints of both
hands. A liver biopsy obtained from the patient is shown above.
The man has no known history of hemolytic anemia and takes daily
multivitamins without minerals. Which of the following pigments
is most likely present in the man's liver?
|
|
|
| (A) |
|
Bilirubin |
| (B) |
|
Carotene |
| (C) |
|
Ferritin |
| (D) |
|
Lipofuscin |
| (E) |
|
Melanin
|
A
57-year-old woman with a history of hypertension and arthritis is
referred to a rheumatologist for evaluation. A complete blood
count (CBC) is normal, and a mini-chem panel shows no electrolyte
abnormalities. Her erythrocyte sedimentation rate (ESR) is
elevated, and an antinuclear antibody test (ANA) is positive.
Further antibody studies are performed, and the results are shown
below.
| |
Anti-histones |
 |
high titer |
|
 |
| |
Anti-double stranded DNA |
|
not detected |
|
|
| |
Anti-single stranded DNA |
|
not detected |
|
|
| |
Anti-SSA |
|
not detected |
|
|
| |
Anti-SSB |
|
not detected |
|
|
| |
Anti-SCI-70 |
|
not detected |
|
|
| |
Anti-Smith |
|
not detected |
|
|
| |
Anti-centromere |
|
not detected |
|
|
| |
Anti-RNP |
|
not detected |
|
Which of the following diseases is suggested
by these results?
|
|
|
| (A) |
|
CREST syndrome |
| (B) |
|
Diffuse form of scleroderma |
| (C) |
|
Drug-induced lupus |
| (D) |
|
Sjögren syndrome |
| (E) |
|
Systemic lupus erythematosus |
During a fight, a
32-year-old man is hit on the back of the neck with a chair. A CT
scan reveals a bony fragment that penetrated the lateral portion
of the dorsal columns. Which of the following functions would
most likely be affected by this lesion?
|
|
|
| (A) |
|
Fine motor control of the ipsilateral
fingers |
| (B) |
|
Motor control of the contralateral foot |
| (C) |
|
Sweating of the ipsilateral face |
| (D) |
|
Proprioception from the ipsilateral leg |
| (E) |
|
Vibratory sense from the ipsilateral
arm |
A 15-year-old high school
student and several of her friends ate lunch at a local Chinese
restaurant. They all were served the daily special, which
consisted of sweet and sour pork with vegetables and fried rice.
All the girls developed nausea, vomiting, abdominal pain, and
diarrhea within 6 hours of eating lunch. Which of the following
organisms is the most likely cause of these
symptoms?
|
|
|
| (A) |
|
Bacillus cereus |
| (B) |
|
Clostridium botulinum |
| (C) |
|
Clostridium perfringens |
| (D) |
|
EHEC (enterohemorrhagic Escherichia
coli) |
| (E) |
|
Staphylococcus aureus |
| (F) |
|
Vibrio cholerae |
