Pathophysiology Practice Exam

Correct Answer: C

Rationale: When the maternal immune system becomes sensitized against antigens expressed by the fetus, an alloimmune reaction occurs. In this situation, the mother's immune system recognizes the fetus as foreign due to differences in antigens, leading to an immune response against the fetus. Choice A, 'Autoimmune,' is incorrect because it refers to the immune system mistakenly attacking the body's own cells and tissues. Choice B, 'Anaphylaxis,' is not the correct answer as it is a severe allergic reaction that can be life-threatening. Choice D, 'Allergic,' is also incorrect as it refers to an immune response triggered by allergens, not antigens expressed by the fetus.

Correct Answer: C

Rationale: Ivermectin (Stromectol) is commonly used to treat parasitic infections, particularly Strongyloides stercoralis. This parasitic infection is known to respond well to Ivermectin therapy. Entamoeba histolytica causes amoebiasis and is typically treated with antiprotozoal drugs like metronidazole, not Ivermectin. Giardia lamblia is a protozoan parasite causing giardiasis, which is usually treated with medications like metronidazole or tinidazole, not Ivermectin. Plasmodium falciparum is a malaria-causing parasite and is not treated with Ivermectin but with antimalarial medications like chloroquine or artemisinin-based combination therapies.

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: The correct answer is A. Finasteride, a type of androgen therapy, has been shown to reduce the risk of developing prostate cancer. It works by shrinking the prostate gland, which can help lower the risk of developing prostate cancer. However, while it may reduce the risk, regular screening is still recommended to monitor for any potential issues. Choice B is incorrect because finasteride does have an impact on reducing the risk of prostate cancer. Choice C is incorrect as finasteride is not known to increase the risk of developing prostate cancer. Choice D is incorrect as finasteride does have an effect on reducing the risk of prostate cancer.

Correct Answer: C

Rationale: Ptosis (drooping eyelid) and diplopia (double vision) are classic symptoms of myasthenia gravis. Muscle atrophy (Choice A) is not a typical early manifestation of myasthenia gravis. While facial weakness (Choice B) can occur, it is not as specific as ptosis and diplopia. Increased muscle tone (Choice D) is more indicative of conditions like spasticity, not myasthenia gravis.