A patient who is infected with hookworms produces signs and symptoms of anemia. Which of the following can be seen in the peripheral blood smear of the patient?

Correct Answer: B

Rationale: The correct answer is B: Basophilic stippling. Hookworm infection can lead to anemia due to chronic blood loss. Basophilic stippling is a characteristic finding in the peripheral blood smear of patients with iron deficiency anemia, which can result from hookworm infection. Basophilic stippling represents the aggregation of ribosomes and is seen in erythrocytes that contain denatured ribosomal RNA. Howell-Jolly bodies are remnants of nuclear material and are typically seen in patients with functional asplenia. Target cells are seen in conditions like liver disease or hemoglobinopathies. Spherocytes are seen in immune hemolytic anemias.

Correct Answer: C

Rationale: The correct answer is C, Microangiopathic hemolytic anemia. Schistocytes are fragmented red blood cells caused by mechanical damage as they pass through narrowed vessels. This occurs in conditions like thrombotic thrombocytopenic purpura and hemolytic uremic syndrome, which are types of microangiopathic hemolytic anemia. Sickle cell trait (A) and Thalassemia (B) are genetic disorders affecting red blood cell structure and production, not causing mechanical fragmentation. Idiopathic thrombocytopenic purpura (D) is a disorder characterized by low platelet count, unrelated to RBC fragmentation.

Correct Answer: C

Rationale: The correct answer is C: Platelets change their shape during the process of platelet aggregation in vascular injury. Platelets undergo shape change from a discoid to a spiky form, leading to the exposure of their glycoprotein receptors, which then bind to fibrinogen and other platelets to form a platelet plug. This process is crucial for hemostasis and preventing excessive bleeding. Explanation for why other choices are incorrect: A: There will be initial vasodilation - Vasodilation is not a direct result of platelet aggregation but rather an initial response to vascular injury to increase blood flow to the area. B: Clotting factors play no role in its formation - Clotting factors are essential for the later stages of hemostasis, but platelet aggregation is primarily driven by platelet activation and shape change. D: Serotonin stimulates platelet aggregation - While serotonin is released from platelets upon activation, it does not directly stimulate platelet aggregation.

Correct Answer: B

Rationale: The correct answer is B because once a mosquito vector, usually Aedes aegypti, is infected with the dengue virus, it remains infective for life. This is due to the virus establishing a lifelong infection in the mosquito's salivary glands. A: Incorrect. Dengue is caused by an RNA virus, specifically the flavivirus. C: Incorrect. Aedes mosquitoes prefer clean, stagnant water for breeding, not polluted water. D: Incorrect. Joint symptoms are common in both dengue fever and chikungunya, but usually more severe in chikungunya.

Correct Answer: C

Rationale: Virchow's node, also known as the left supraclavicular node, receives lymphatics primarily from the abdomen. The correct answer is C (prostate) because the prostate does not drain into Virchow's node. The stomach, breast, and testes all have lymphatic connections to Virchow's node. This is due to the anatomical location of these organs and their respective lymphatic drainage pathways. The stomach drains into the celiac lymph nodes, which then connect to Virchow's node. The breast drains into the axillary lymph nodes, which also communicate with Virchow's node. The testes drain into the para-aortic lymph nodes, which eventually lead to Virchow's node. Therefore, C is the correct answer based on the unique lymphatic drainage patterns of these organs.