MEDSTUDENTS - USMLE Step 1 Questions and Answers
(A) Incorrect.
(B) Incorrect.
(C)
CORRECT. Furosemide is the prototype loop diuretic. It inhibit the
cotransporter of sodium, potassium , and chloride in the loop of Henle.
Inhibition of the transport also results in loss of the lumen-positive
potential, which reduces reabsorption of divalent cations as well. As a
result, calcium excretion is significantly increased.
(D) Incorrect.
(E) Incorrect.
(A) Incorrect.
(B) Incorrect.
(C) CORRECT.
(D) Incorrect.
(E) Incorrect.
(A) Incorrect.
(B) Incorrect..
(C) Incorrect.
(D) CORRECT.The physician should use alternative means of replacing body
fluids but not give the patient the blood transfusion. Mentally
competent patients may refuse treatment.
(E) Incorrect.
(A) Incorrect.
(B) CORRECT.
(C) Incorrect.
(D) Incorrect
(E) Incorrect.
(A) Incorrect.
(B) CORRECT.
(C) Incorrect.
(D) Incorrect.
(E) Incorrect.
(A) Incorrect.
(B) Incorrect
(C) CORRECT. Multiple myeloma often presents with diffuse demineralization
of bone, even though punched-out lesions are more characteristic.
Findings that distinguish it from other conditions that cause
demineralization are anemia, hypergammaglobulinemia, proteinuria, and
NORMAL(rather than elevated) serum alkaline phosphatase.
(D) Incorrect
(E) Incorrect.
(A) Incorrect..
(B) Incorrect.
(C) Incorrect.
(D) CORRECT. Chylomicrons are blood lipoproteins produced from dietary fat.
VLDL are produced mainly from dietary carbohydrate. IDL and LDL are
produced from VLDL.
(E) Incorrect
(A) Incorrect.
(B) CORRECT. The axillary nerve, with the posterior circumflex artery,
passes through the quadrangular space and crosses the surgical neck of
the humerus, where it is susceptible to injury in fracture and in
dislocation of the shoulder joint.
(C) Incorrect.
(D) Incorrect.
(E) Incorrect
(A) Incorrect.
(B) Incorrect.
(C) Incorrect. .
(D) CORRECT.
(E) Incorrect
(A) Incorrect.
(B)CORRECT. The frequency can be calculated from the Hardy-Weinberg law,
in which the carrier frequency is equal 2 pq. q is calculated by taking
the square root of the incidence, which gives the frequency of the gene,
1 in 60, and p equal to 1-q, or 60/60-1/60, which gives 59/60. As can be
seen here, in most cases of rare diseases, p becomes equal to 1, and the
carrier frequency becomes 2q, or 2 times 1/60, which gives the
frequency of 1/30.
(C) CORRECT.
(D) Incorrect.
(E) Incorrect. .