ATI Pathophysiology Test Bank

Correct Answer: A

Rationale: The correct answer is A. Raloxifene works by decreasing bone resorption and increasing bone density. This helps in strengthening bones, reducing the risk of fractures, and improving bone health in patients with osteoporosis. Choice B is incorrect because raloxifene does not directly stimulate the formation of new bone but rather prevents bone loss. Choice C is incorrect as raloxifene does not primarily affect calcium absorption in the intestines. Choice D is also incorrect as raloxifene does not primarily decrease the excretion of calcium through the kidneys.

Correct Answer: B

Rationale: When a patient with active tuberculosis is not responding to antitubercular drug therapy, drug-resistant tuberculosis should be suspected. Drug-resistant tuberculosis occurs when the bacteria causing tuberculosis become resistant to the medications being used. Choices A, C, and D are incorrect because the scenario described does not align with HIV infection, methicillin-resistant Staphylococcus aureus, or vancomycin-resistant Staphylococcus aureus.

Correct Answer: C

Rationale: Intravenous amphotericin can cause nephrotoxicity, leading to increased blood urea nitrogen levels. Elevated blood urea nitrogen (BUN) indicates impaired renal function, which is a known adverse effect of amphotericin. Therefore, a BUN level of 60 mg/dL warrants the discontinuation of the antifungal agent. The other options, such as a sodium level of 138 mEq/L, hematocrit of 39%, and AST level of 10 Unit/L, are within normal ranges and not indicative of the need to discontinue amphotericin therapy.

Correct Answer: B

Rationale: The correct answer is B: Purulent. Purulent exudates, or pus, consist primarily of leukocytes and dead cells, indicating a bacterial infection. Serous exudates contain a thin, watery fluid with few leukocytes. Fibrinous exudates are rich in fibrin and are commonly seen in severe inflammation. Hemorrhagic exudates contain red blood cells due to blood vessel damage.

Correct Answer: C

Rationale: Antigens are the correct answer as they are the molecules that trigger the immune response by binding to specific B or T cells. This binding activates these cells, leading to their proliferation and differentiation to fight off the antigen. B cells and T cells are the responders to antigens, not the initiators of clonal selection. Lymphocytes is a broad term encompassing both B and T cells, so it is not the specific factor responsible for initiating clonal selection.