Pathophysiology Practice Exam

Correct Answer: A

Rationale: An attenuated antigen used in a vaccine is alive but less infectious, aiming to stimulate an immune response. Choice B is incorrect because an attenuated antigen is not highly infectious. Choice C is incorrect as the antigen is intentionally altered to be less infectious. Choice D is incorrect as an attenuated antigen is not infectious.

Correct Answer: B

Rationale: The correct answer is B because hormone replacement therapy (HRT) is associated with an increased risk of cardiovascular events, including venous thromboembolism. Patients with a history of venous thromboembolism are at higher risk, so discussing this potential risk is crucial. Choice A, increased bone density, is not a major risk of HRT. Choice C, reduced risk of breast cancer, is not a common discussion point regarding HRT risks. Choice D, improved mood and energy levels, is more related to the benefits of HRT rather than its risks.

Correct Answer: B

Rationale: The correct answer is B: Size. Muscular atrophy is characterized by a reduction in the size of muscle cells. This decrease in size can be due to various factors such as disuse, aging, or disease. Choice A, Number, is incorrect because muscular atrophy does not involve a decrease in the number of muscle cells but rather their size. Choice C, Vacuoles, is incorrect as vacuoles are not directly related to the definition of muscular atrophy. Choice D, Lipofuscin, is incorrect as lipofuscin is a pigment associated with aging and has no direct connection to the decrease in muscle cell size seen in muscular atrophy.

Correct Answer: A

Rationale: In a patient with an autoimmune disorder, a viral infection can trigger an immune response where lymphocytes mistakenly recognize the host's tissue as foreign. This can lead to an exacerbation of the autoimmune condition. Choice B is incorrect because erythrocytes are not responsible for destroying T cells. Choice C is incorrect as thymus involution weakens the immune response, making the patient more susceptible to infections rather than increasing the infection risk. Choice D is unrelated to the potential effects of a viral infection in a patient with an autoimmune disorder.

Correct Answer: A

Rationale: An attenuated antigen used in a vaccine is alive but less infectious, aiming to stimulate an immune response. Choice B is incorrect because an attenuated antigen is not highly infectious. Choice C is incorrect as the antigen is intentionally altered to be less infectious. Choice D is incorrect as an attenuated antigen is not infectious.