A 20-year-old male shoots his hand with a nail gun while replacing roofing shingles. Which of the following cell types would be the first to aid in killing bacteria to prevent infection in his hand?

Correct Answer: B

Rationale: Neutrophils are the first responders to bacterial infections. When there is a breach in the skin like in this scenario, neutrophils are quickly recruited to the site of injury to phagocytize and kill bacteria. Eosinophils are primarily involved in parasitic infections and allergic reactions, making choice A incorrect. Leukotrienes are lipid mediators involved in inflammation but are not cells, so choice C is incorrect. Monocytes are precursors to macrophages and play a role in immune response, but they are not the first cells to arrive at the site of a bacterial infection, making choice D incorrect.

Correct Answer: D

Rationale: Anemia of chronic inflammation is characterized by normochromic and normocytic red blood cells. In chronic inflammation, the body typically produces enough red blood cells, but they are often smaller and paler than normal (normocytic and normochromic). Choices A, B, and C are incorrect because hypochromic and microcytic, hypochromic and macrocytic, and normochromic and microcytic anemias are not typically associated with chronic inflammation.

Correct Answer: B

Rationale: HbAS indicates sickle cell trait, not full-blown sickle cell anemia. Choice A is incorrect because HbAS indicates the presence of the sickle cell trait. Choice C is incorrect as sickle cell anemia is characterized by HbSS, not HbAS. Choice D is incorrect as thalassemia is a different type of hemoglobin disorder not indicated by HbAS.

Correct Answer: B

Rationale: In peripheral artery disease, pain in the lower extremities worsens with the elevation of the extremity because it diverts blood flow away from the affected area, exacerbating the pain. Choices A, C, and D are incorrect. Resting doesn't increase blood flow, a dependent position doesn't lead to blood pooling in this context, and pain worsening due to touch or massage is not a typical feature of peripheral artery disease.

Correct Answer: A

Rationale: The correct answer is A. Alpha-1 antitrypsin deficiency is a genetic condition that can lead to COPD at a young age, even in light smokers. Choice B is less likely as the patient's occupation does not directly correlate with alpha-1 antitrypsin deficiency. Choice C, a 70-year-old woman with a long smoking history, is more likely to have COPD due to smoking rather than alpha-1 antitrypsin deficiency. Choice D, exposure to secondhand smoke, is not a common cause of alpha-1 antitrypsin deficiency-related COPD.